Anatomy & Physiology I Exam 1

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What are the three types of muscle tissue?

Skeletal Cardiac Smooth

Hip Joint . Rim of fibrocartilage that enhances depth of socket (hip dislocations are rare)

Acetabular Labrum

What are the three types of bone markings?

Projection Depression Opening

• For cushioning between fibrous layer of capsule and synovial membrane or bone

Fatty Pads

One or more cells that makes and secretes an aqueous fluid called a secretion

Gland

Cells that destroy bone

Osteoclasts

Sensor - Monitors environment - Responds to stimuli (things that cause changes in controlled variables)

Receptor

Homeostatic control of variables involves three components: ______, ______ _____, and ______

Receptor Control center Effector

-Appears poorly organized but is actually organized along lines of stress to help bone resist any stress -Trabeculae, like cables on a suspension bridge, confer strength to bone •No osteons are present, but trabeculae do contain irregularly arranged lamellae and osteocytes interconnected by canaliculi •Capillaries in endosteum supply nutrients

Spongy Bone

Epithelia Flattened and scale-like

Squamous

•Cells of bone tissue -Five major cell types, each of which is a specialized form of the same basic cell type 1. Osteogenic cells 2. Osteoblasts 3. Osteocytes 4. Bone-lining cells 5. Osteoclasts . Cells 1. Osteogenic cells -Also called osteoprogenitor cells -Mitotically active stem cells in periosteum and endosteum -When stimulated, they differentiate into osteoblasts or bone-lining cells -Some remain as osteogenic stem cells 2. Osteoblasts -Bone-forming cells that secrete unmineralized bone matrix called osteoid •Osteoid is made up of collagen and calcium-binding proteins •Collagen makes up 90% of bone protein -Osteoblasts are actively mitotic 3. Osteocytes -Mature bone cells in lacunae that no longer divide -Maintain bone matrix and act as stress or strain sensors •Respond to mechanical stimuli such as increased force on bone or weightlessness •Communicate information to osteoblasts and osteoclasts (cells that destroy bone) so bone remodeling can occur 4. Bone-lining cells -Flat cells on bone surfaces believed to also help maintain matrix (along with osteocytes) -On external bone surface, lining cells are called periosteal cells -On internal surfaces, they are called endosteal cells 5. Osteoclasts -Derived from same hematopoietic stem cells that become macrophages -Giant, multinucleate cells function in bone resorption (breakdown of bone) -When active, cells are located in depressions called resorption bays -Cells have ruffled borders that serve to increase surface area for enzyme degradation of bone •Also helps seal off area from surrounding matrix •Compact bone -Also called lamellar bone -Consists of: •Osteon (Haversian system) •Canals and canaliculi •Interstitial and circumferential lamella •Osteon (Haversian system) -An osteon is the structural unit of compact bone -Consists of an elongated cylinder that runs parallel to long axis of bone •Acts as tiny weight-bearing pillars -An osteon cylinder consists of several rings of bone matrix called lamellae •Lamellae contain collagen fibers that run in different directions in adjacent rings •Withstands stress and resist twisting •Bone salts are found between collagen fibers •Canals and canaliculi -Central (Haversian) canal runs through core of osteon •Contains blood vessels and nerve fibers -Perforating (Volkmann's) canals: canals lined with endosteum that occur at right angles to central canal •Connect blood vessels and nerves of periosteum, medullary cavity, and central canal -Lacunae: small cavities that contain osteocytes -Canaliculi: hairlike canals that connect lacunae to each other and to central canal -Osteoblasts that secrete bone matrix maintain contact with each other and osteocytes via cell projections with gap junctions -When matrix hardens and cells are trapped the canaliculi form •Allow communication between all osteocytes of osteon and permit nutrients and wastes to be relayed from one cell to another •Interstitial and circumferential lamellae -Interstitial lamellae •Lamellae that are not part of osteon •Some fill gaps between forming osteons; others are remnants of osteons cut by bone remodeling -Circumferential lamellae •Just deep to periosteum, but superficial to endosteum, these layers of lamellae extend around entire surface of diaphysis •Help long bone to resist twisting •Spongy bone -Appears poorly organized but is actually organized along lines of stress to help bone resist any stress -Trabeculae, like cables on a suspension bridge, confer strength to bone •No osteons are present, but trabeculae do contain irregularly arranged lamellae and osteocytes interconnected by canaliculi •Capillaries in endosteum supply nutrients

Anatomy of Bones

Connective Tissue Proper Loose Connective Tissue

Areolar Adipose Reticular

Most atypical connective tissue because it is fluid

Blood

• Skin can hold up to 5% of the body's total blood volume • Skin vessels can be constricted to shunt blood to other organs, such as an exercising muscle

Blood Resevoir

-Surfaces along which body or structures may be cut for anatomical study -Three most common planes: •Sagittal plane •Frontal (coronal) plane •Transverse (horizontal) plane

Body Planes

• Under normal, resting body temperature, sweat glands produce about 500 ml/day of unnoticeable sweat - Called insensible perspiration • If body temperature rises, dilation of dermal vessels can increase sweat gland activity to produce 12 L (3 gallons) of noticeable sweat - Called sensible perspiration; designed to cool body • Cold external environment - Dermal blood vessels constrict - Skin temperature drops to slow passive heat loss

Body Temperature Regulation

- Also called osseous tissue - Supports and protects body structures - Stores fat and synthesizes blood cells in cavities - Has more collagen compared to cartilage - Has inorganic calcium salts - Osteoblasts produce matrix - Osteocytes maintain the matrix • Reside in cavities in matrix called lacunae - Osteons: individual structural units - Richly vascularized Description:Hard, calcified matrix containing many collagen fibers; osteocytes lie in lacunae. Very well vascularized. Function:Supports and protects (by enclosing); provides levers for the muscles to act on; stores calcium and other minerals and fat; marrow inside bones is the site for blood cell formation (hematopoiesis). Location: Bones

Bone

Osseous tissue

Bone

Reduce friction where ligaments, muscles, skin, tendons, or bones rub together

Bursae

Synovial Joints Thickened part of fibrous layer

Capsular

What are the three types of reinforcing ligaments in synovial joints?

Capsular Extracapsular Intracapsular

Major Source of energy

Carbohydrates

What are the different things in nutrients?

Carbohydrates Proteins Fats Minerals and vitamins

Muscles of heart

Cardiac

- ________ ________ tissue is found only in heart • Makes up bulk of heart walls - Striated - Involuntary: cannot be controlled consciously • Contracts at steady rate due to heart's own pacemaker, but nervous system can increase rate - Key words for cardiac muscle: cardiac, striated, and involuntary

Cardiac Muscle

- Found only in walls of heart - Involuntary muscle - Like skeletal muscle, contains striations; but cells have only one nucleus - Cells can have many branches that join branches of other cardiac cells • Intercalated discs are special joints where cardiac cells are joined Description:Branching, striated, generally uninucleate cells that interdigitate at specialized junctions (intercalated discs). Function:As it contracts, it propels blood into the circulation; involuntary control. Location:The walls of the heart.

Cardiac Muscle Tissue

• Tissues with virtually no functional regenerative capacity: - _____ _____ and _____ _____ of brain and _____ _____ - New research shows ______ _____ does occur, and efforts are underway to coax them to regenerate better

Cardiac muscle Nervous tissue Spinal cord Cell division

Blood vessels transport blood, which carries oxygen, carbon dioxide, nutrients, wastes, etc. The heart pumps blood.

Cardiovascular System

•There are seven important functions of _______: 1. Support •For body and soft organs 2. Protection •Protect brain, spinal cord, and vital organs 3. Movement •Levers for muscle action 4. Mineral and growth factor storage •Calcium and phosphorus, and growth factors reservoir 5. Blood cell formation •Hematopoiesis occurs in red marrow cavities of certain _______ 6. Triglyceride (fat) storage •Fat, used for an energy source, is stored in bone cavities 7. Hormone production •Osteocalcin secreted by bones helps to regulate insulin secretion, glucose levels, and metabolism •206 named ______ in human skeleton •Divided into two groups based on location -Axial skeleton •Long axis of body •Skull, vertebral column, rib cage -Appendicular skeleton •Bones of upper and lower limbs •Girdles attaching limbs to axial skeleton •_____ are also classified according to one of four shapes: 1. Long ______ •Longer than they are wide •Limb ______ 2. Short ______ •Cube-shaped _______ (in wrist and ankle) •Sesamoid ______ form within tendons (example: patella) •Vary in size and number in different individuals 3. Flat ______ •Thin, flat, slightly curved •Sternum, scapulae, ribs, most skull ______ 4. Irregular _____ •Complicated shapes •Vertebrae and hip _____ •_____ are organs because they contain different types of tissues •______ (osseous) tissue predominates, but a bone also has nervous tissue, cartilage, fibrous connective tissue, muscle cells, and epithelial cells in its blood vessels •Three levels of structure -Gross -Microscopic -Chemical . Gross Anatomy •Compact and spongy _____ -Compact _____: dense outer layer on every bone that appears smooth and solid -Spongy ______: made up of a honeycomb of small, needle-like or flat pieces of bone called trabeculae •Open spaces between trabeculae are filled with red or yellow _____ marrow •Structure of short, irregular, and flat _____ -Consist of thin plates of spongy _____ (diploe) covered by compact ______ -Compact _____ sandwiched between connective tissue membranes •Periosteum covers outside of compact _____, and endosteum covers inside portion of compact _____ -_______ marrow is scattered throughout spongy _____; no defined marrow cavity -Hyaline cartilage covers area of _____ that is part of a movable joint •Structure of typical long ______ -All long _____ have a shaft (diaphysis), ______ ends (epiphyses), and membranes •Diaphysis: tubular shaft that forms long axis of _____ -Consists of compact ______ surrounding central medullary cavity that is filled with yellow marrow in adults •Epiphyses: ends of long _____ that consist of compact ______ externally and spongy ______ internally -Articular cartilage covers articular (joint) surfaces •Between diaphysis and epiphysis is epiphyseal line -Remnant of childhood epiphyseal plate where _____ growth occurs •Membranes: two types (periosteum and endosteum) -Periosteum: white, double-layered membrane that covers external surfaces except joints » Fibrous layer: outer layer consisting of dense irregular connective tissue consisting of Sharpey's fibers that secure to bone matrix » Osteogenic layer: inner layer abutting bone and contains primitive osteogenic stem cells that gives rise to most all ______ cells » Contains many nerve fibers and blood vessels that continue on to the shaft through nutrient foramen openings » Anchoring points for tendons and ligaments •Hematopoietic tissue in ______ -Red marrow is found within trabecular cavities of spongy ______ and diploë of flat ______, such as sternum •In newborns, medullary cavities and all spongy _______ contain red marrow •In adults, red marrow is located in heads of femur and humerus, but most active areas of hematopoiesis are flat ______ diploë and some irregular _______ (such as the hip _______) •Yellow marrow can convert to red, if person becomes anemic •______ markings -Sites of muscle, ligament, and tendon attachment on external surfaces -Areas involved in joint formation or conduits for blood vessels and nerves -Three types of markings: •Projection: outward bulge of ______ -May be due to increased stress from muscle pull or is a modification for joints •Depression: bowl- or groove-like cut-out that can serve as passageways for vessels and nerves, or plays a role in joints •Opening: hole or canal in bone that serves as passageways for blood vessels and nerves •Cells of ______ tissue -Five major cell types, each of which is a specialized form of the same basic cell type 1. Osteogenic cells 2. Osteoblasts 3. Osteocytes 4. ______-lining cells 5. Osteoclasts . Cells 1. Osteogenic cells -Also called osteoprogenitor cells -Mitotically active stem cells in periosteum and endosteum -When stimulated, they differentiate into osteoblasts or ______-lining cells -Some remain as osteogenic stem cells 2. Osteoblasts -_____-forming cells that secrete unmineralized ______ matrix called osteoid •Osteoid is made up of collagen and calcium-binding proteins •Collagen makes up 90% of _____ protein -Osteoblasts are actively mitotic 3. Osteocytes -Mature ______ cells in lacunae that no longer divide -Maintain ______ matrix and act as stress or strain sensors •Respond to mechanical stimuli such as increased force on ______ or weightlessness •Communicate information to osteoblasts and osteoclasts (cells that destroy bone) so _____ remodeling can occur 4. _______-lining cells -Flat cells on ______ surfaces believed to also help maintain matrix (along with osteocytes) -On external ______ surface, lining cells are called periosteal cells -On internal surfaces, they are called endosteal cells 5. Osteoclasts -Derived from same hematopoietic stem cells that become macrophages -Giant, multinucleate cells function in ______ resorption (breakdown of ______) -When active, cells are located in depressions called resorption bays -Cells have ruffled borders that serve to increase surface area for enzyme degradation of ______ •Also helps seal off area from surrounding matrix •Compact _____ -Also called lamellar ______ -Consists of: •Osteon (Haversian system) •Canals and canaliculi •Interstitial and circumferential lamella •Osteon (Haversian system) -An osteon is the structural unit of compact ______ -Consists of an elongated cylinder that runs parallel to long axis of ______ •Acts as tiny weight-bearing pillars -An osteon cylinder consists of several rings of _____ matrix called lamellae •Lamellae contain collagen fibers that run in different directions in adjacent rings •Withstands stress and resist twisting •______ salts are found between collagen fibers •Canals and canaliculi -Central (Haversian) canal runs through core of osteon •Contains blood vessels and nerve fibers -Perforating (Volkmann's) canals: canals lined with endosteum that occur at right angles to central canal •Connect blood vessels and nerves of periosteum, medullary cavity, and central canal -Lacunae: small cavities that contain osteocytes -Canaliculi: hairlike canals that connect lacunae to each other and to central canal -Osteoblasts that secrete ______ matrix maintain contact with each other and osteocytes via cell projections with gap junctions -When matrix hardens and cells are trapped the canaliculi form •Allow communication between all osteocytes of osteon and permit nutrients and wastes to be relayed from one cell to another •Interstitial and circumferential lamellae -Interstitial lamellae •Lamellae that are not part of osteon •Some fill gaps between forming osteons; others are remnants of osteons cut by ______ remodeling -Circumferential lamellae •Just deep to periosteum, but superficial to endosteum, these layers of lamellae extend around entire surface of diaphysis •Help long _____ to resist twisting •Spongy ______ -Appears poorly organized but is actually organized along lines of stress to help _____ resist any stress -Trabeculae, like cables on a suspension bridge, confer strength to _____ •No osteons are present, but trabeculae do contain irregularly arranged lamellae and osteocytes interconnected by canaliculi •Capillaries in endosteum supply nutrients . Chemical makeup of ____ •_____ is made up of both organic and inorganic components -Organic components •Includes osteogenic cells, osteoblasts, osteocytes, ______-lining cells, osteoclasts, and osteoid -Osteoid, which makes up one-third of organic _____ matrix, is secreted by osteoblasts » Consists of ground substance and collagen fibers, which contribute to high tensile strength and flexibility of ______ -Resilience of _____ is due to sacrificial bonds in or between collagen molecules that stretch and break to dissipate energy and prevent fractures -If no additional trauma, bonds re-form •Inorganic components -Hydroxyapatites (mineral salts) •Makeup 65% of ______ by mass •Consist mainly of tiny calcium phosphate crystals in and around collagen fibers •Responsible for hardness and resistance to compression -_____ is half as strong as steel in resisting compression and as strong as steel in resisting tension -Lasts long after death because of mineral composition -Can reveal information about ancient people • Ossification (osteogenesis) is the process of _____ tissue formation - Formation of ______ skeleton begins in month 2 of development - Postnatal ______ growth occurs until early adulthood - _______ remodeling and repair are lifelong

Bones

- Within one week, new trabeculae appear in fibrocartilaginous callus - Callus is converted to bony (hard) callus of spongy bone - _______ _______ ______ continues for about 2 months until firm union forms

Bony Callus Formation

• Inadequate steroid hormones (example: Addison's disease)

Bronzing

• Clotted blood beneath skin . Black and blue marks

Bruises

• Tissue damage caused by heat, electricity, radiation, or certain chemicals - Damage caused by denaturation of proteins, which destroys cells • Immediate threat is dehydration and electrolyte imbalance - Leads to renal shutdown and circulatory shock • To evaluate _____, the Rule of Nines is used - Body is broken into 11 sections, with each section representing 9% of body surface (except genitals, which account for 1%) • _____ can be classified by severity - First-degree • Epidermal damage only - Localized redness, edema (swelling), and pain - Second-degree • Epidermal and upper dermal damage - Blisters appear - First- and second-degree burns are referred to as partial-thickness burns because only the epidermis and upper dermis are involved - Third-degree • Entire thickness of skin involved (referred to as full-thickness burns) • Skin color turns gray-white, cherry red, or blackened • No edema is seen and area is not painful because nerve endings are destroyed • Skin grafting usually necessary • ______ are considered critical if: - >25% of body has second-degree _____ - >10% of body has third-degree ______ - Face, hands, or feet bear third-degree ______ • Treatment includes: - Debridement (removal) of burned skin - Antibiotics - Temporary covering - Skin grafts

Burns

Cell type not found in areolar connective tissue. A. Macrophages B. Mast cells C. Fibroblasts D. Chondrocytes

Changes in the color of skin are often an indication of a homeostatic imbalance. Which of the following changes would suggest that a patient is suffering from Addison's disease? A. Black-and-blue marks become evident for no apparent cause. B. It is impossible to suggest Addison's disease from an inspection of a person's skin. C. The skin appears to have an abnormal, yellowish tint. D. The skin takes on a bronze or metallic appearance

2. Generation and propagation of an action potential (AP) - If end plate potential causes enough change in membrane voltage to reach critical level called threshold, voltage-gated Na+ channels in membrane will open - Large influx of Na+ through channels into cell triggers AP that is unstoppable and will lead to muscle fiber contraction - AP spreads across sarcolemma from one voltage-gated Na+ channel to next one in adjacent areas, causing that area to depolarize

Depolarization

Skeletal Muscle Tissue Attachments . Epimysium fused to periosteum of bone or perichondrium of cartilage

Direct

To be viewed under a microscope, tissue must be?

Fixed Sectioned Stained

•Thin, ____, slightly curved •Sternum, scapulae, ribs, most skull bones

Flat Bones

Angular Movements . Decreases the angle of the joint

Flexion

Synovial Joints Muscles Attachment to movable bone

Instertion

Forms the external body covering, and protects deeper tissues from injury. Synthesizes vitamin D, and houses cutaneous (pain, pressure, etc.) receptors and sweat and oil glands.

Integumentary System

Special joints where cardiac cells are joined

Intercalated Discs

Between a more medial and a more lateral structure

Intermediate

•Chondrocytes within lacunae divide and secrete new matrix, expanding cartilage from within -New matrix made within cartilage

Interstitial Growth

•Lamellae that are not part of osteon •Some fill gaps between forming osteons; others are remnants of osteons cut by bone remodeling

Interstitial Lamella

-_______ _______ •________ that are not part of osteon •Some fill gaps between forming osteons; others are remnants of osteons cut by bone remodeling -________ _______ •Just deep to periosteum, but superficial to endosteum, these layers of lamellae extend around entire surface of diaphysis •Help long bone to resist twisting

Interstitial and Circumferential Lamellae

Synovial Joints Deep to capsule; covered by synovial membrane

Intracapsular

- Bone develops from fibrous membrane - Bones are called membrane bones

Intramembranous Bones

. Begins within fibrous connective tissue membranes formed by mesenchymal cells - Forms frontal, parietal, occipital, temporal, and clavicle bones • Four major steps are involved: 1. _______ centers are formed when mesenchymal cells cluster and become osteoblasts 2. Osteoid is secreted, then calcified 3. Woven bone is formed when osteoid is laid down around blood vessels, resulting in trabeculae • Outer layer of woven bone forms periosteum 4. Lamellar bone replaces woven bone, and red marrow appears

Intramembranous Ossification

Epithelial sheet lies over layer of loose connective tissue

Lamina Propria

. Small, fluid-filled potential space that is unique to synovial joints

Joint Cavity

• _______, also called articulations: sites where two or more bones meet • Functions of joints: give skeleton mobility and hold skeleton together • Two classifications: 1. Structural: three types based on what material binds the ______ and whether a cavity is present • Fibrous • Cartilaginous • Synovial 2. Functional classifications: three types based on movement ______ allows • Synarthroses: immovable joints • Amphiarthroses: slightly movable joints • Diarthroses: freely movable joints • Structural classifications are more clear cut, so these will be used here

Joints

• Produce fibrous keratin (protein that gives skin its protective properties) • Major cells of epidermis • Tightly connected by desmosomes • Millions slough off every day

Keratinocytes

What are the four cell types of the Epidermis?

Keratinocytes Melanocytes Dendritic Tactile

• Largest, most complex joint of body • Consists of three joints surrounded by single cavity 1. Femoropatellar joint • Plane joint • Allows gliding motion during knee flexion 2. Lateral joint and 3. Medial joint • Lateral and medial joints together are called tibiofemoral joint • Joint between femoral condyles and lateral and medial menisci of tibia • Hinge joint that allows flexion, extension, and some rotation when knee partly flexed • Joint capsule is thin and absent anteriorly • Anteriorly, quadriceps tendon gives rise to three broad ligaments that run from patella to tibia - Medial and lateral patellar retinacula that flank the patellar ligament • Doctors tap patellar ligament to test knee-jerk reflex • At least 12 bursae associated with ______ ______ • Capsular, extracapsular, or intracapsular ligaments act to stabilize knee joint • Capsular and extracapsular ligaments help prevent hyperextension of knee - Fibular and tibial collateral ligaments: prevent rotation when knee is extended - Oblique popliteal ligament: stabilizes posterior _____ _______ - Arcuate popliteal ligament: reinforces joint capsule posteriorly • Intracapsular ligaments reside within capsule, but outside synovial cavity • Help to prevent anterior-posterior displacement - Anterior cruciate ligament (ACL) • Attaches to anterior tibia • Prevents forward sliding of tibia and stops hyperextension of knee - Posterior cruciate ligament • Attaches to posterior tibia • Prevents backward sliding of tibia and forward sliding of femur • Knee absorbs great amount of vertical force; however, it is vulnerable to horizontal blows - Common knee injuries involved the 3 C's: • Collateral ligaments • Cruciate ligaments • Cartilages (menisci) - Lateral blows to extended knee can result in tears in tibial collateral ligament, medial meniscus, and anterior cruciate ligament - Injuries affecting just ACL are common in runners who change direction, twisting ACL

Knee Joint

What are the 5 main synovial joints?

Knee Shoulder Elbow Hip Jaw

Picks up fluid leaked from blood vessels and returns it to blood. Disposes of debris in the lymphatic stream. Houses white blood cells (lymphocytes) involved in immunity.

Lymphatic System

Skeletal Muscle Fibers Myofibrils Striations A Bands H Zone . Line of protein (myomesin) that bisects H zone vertically

M Line

Connective Tissue • Phagocytic cells that "eat" dead cells, microorganisms; function in immune system

Macrophages

Overall function is production of offspring. Testes produce sperm and male sex hormone, and male ducts and glands aid in delivery of sperm to the female reproductive tract. Ovaries produce eggs and female sex hormones. The remaining female structures serve as sites for fertilization and development of the fetus. Mammary glands of female breasts produce milk to nourish the newborn.

Male Reproductive System

What are the prefixes for muscle?

Mao Mys Sarco

Connective Tissue • Initiate local inflammatory response against foreign microorganisms they detect

Mast Cells

Serous membrane •Thin, double-layered membranes that cover surfaces in ventral body cavity -Parietal serosa lines internal body cavity walls -Visceral serosa covers internal organs (viscera) •Double layers are separated by slit-like cavity filled with serous fluid •Fluid secreted by both layers of membrane

Serosa

Serosae

Serous Membranes

• Also called serosae • Found in closed ventral body cavities • Constructed from simple squamous epithelium (called mesothelium) resting on thin areolar connective tissue • Parietal serosae line internal body cavity walls • Visceral serosae cover internal organs • Cavity between layers is filled with slippery serous fluid, so these are moist membranes • Special names given to show location: pleurae (lungs), pericardium (heart), peritoneum (abdomen)

Serous Membranes

Bones form within tendons (example: patella)

Sesamoid

. Made of highly resilient, molded cartilage tissue that consists primarily of water -Contains no blood vessels or nerves

Skeletal Cartilage

Muscle Fiber Contraction Cross Bridge Cycling . Myosin head pivots and pulls thin filament toward M line

Working Stroke

Skeletal Muscle Fibers Myofibrils Striations I Bands . Coin-shaped sheet of proteins on midline of light I band

Z Disc

Peritoneum

Abdomen

. Small cavities that contain osteocytes

Lacunae

Cavities in matrix

Lacunae

Encases brain

Cranial Cavity

What are the two parts of a dorsal body cavity?

Cranial Vertebral

Muscle Fiber Contraction Cross Bridge Cycling . ATP attaches to myosin head, causing cross bridge to detach

Cross Bridge Detachment

Muscle Fiber Contraction Cross Bridge Cycling . High-energy myosin head attaches to actin thin filament active site

Cross Bridge Formation

What are the four steps to cross bridge cycle?

Cross bridge formation Working stroke Cross bridge detachment Cocking of myosin head

Epithelia Box-like, cube

Cuboidal

• Another name for skin • Keratinized stratified squamous epithelium (epidermis) attached to a thick layer of connective tissue (dermis) • Unlike other membranes, skin is a dry membrane . The _____ ______ (the skin) covers the body surface.

Cutaneous Membranes

What are the three types of covering and lining membranes?

Cutaneous Mucous Serous

• ________ sensory receptors are part of the nervous system - Exteroreceptors respond to stimuli outside body, such as temperature and touch - Free nerve endings sense painful stimuli

Cutaneous Sensations

• Blue skin color: low oxygenation of hemoglobin

Cyanosis

• Mature, less active form of "blast" cell that now becomes part of and helps maintain health of matrix

Cyte Cells

Microscopic study of cells

Cytology

A joint united by fibrocartilage tissue that usually permits a slight degree of movement is a ________. A. Syndesmosis B. Gomphosis C. Suture D. Symphysis

A splinter penetrated into the skin of the sole of the foot, almost to the papillary region of the dermis. Which layer of the epidermis would be the final layer injured? A. Spinosum B. Granulosum C. Lucidum D. Basale

An anaerobic metabolic pathway that results in the production of two net ATPs per glucose plus two pyruvic acid molecules is ________. A. The electron transport chain B. The citric acid cycle C. Hydrolysis D. Glycolysis

An example of an interosseous fibrous joint is ________. A. Between the humerus and the glenoid cavity B. Between the vertebrae C. The clavicle and the scapula at the distal ends D. The radius and ulna along its length

Apocrine glands, which begin to function at puberty under hormonal influence, seem to play little role in thermoregulation. Where would we find these glands in the human body? A. In all body regions and buried deep in the dermis B. In the palms of the hands and soles of the feet C. Beneath the flexure lines in the body D. In the axillary and anogenital area

Arteries, veins, and lymphatics keep clots from sticking as long as their ________ is intact and healthy. A. Mesothelium B. Simple cuboidal epithelium C. Transitional epithelium D. Endothelium

Articulations permitting only slight degrees of movement are ________. A. Synarthroses B. Synovial joints C. Diarthroses D. Amphiarthroses

Average body temperature is ________ degrees centigrade. A. 68 B. 98 C. 47 D. 37

Elongated bursae wrapped completely around tendons subjected to friction

Tendon Sheathes

- Inflammation of tendon sheaths, typically caused by overuse - Symptoms and treatment similar to those of bursitis

Tendonitis

. Coarse, long hair - Found on scalp and eyebrows - At puberty • Appear in axillary and pubic regions of both sexes • Also on face and neck of males

Terminal Hair

Muscle Fiber Contraction • Skeletal muscles are stimulated by somatic motor neurons • Axons (long, threadlike extensions of motor neurons) travel from central nervous system to skeletal muscle • Each axon divides into many branches as it enters muscle • Axon branches end on muscle fiber, forming neuromuscular junction or motor end plate - Each muscle fiber has one neuromuscular junction with one motor neuron • Axon terminal (end of axon) and muscle fiber are separated by gel-filled space called synaptic cleft • Stored within axon terminals are membrane-bound synaptic vesicles - Synaptic vesicles contain neurotransmitter acetylcholine (ACh) • Infoldings of sarcolemma, called junctional folds, contain millions of ACh receptors • NMJ consists of axon terminals, synaptic cleft, and junctional folds • Events at the neuromuscular junction - Nerve impulse arrives at axon terminal, causing ACh to be released into synaptic cleft - ACh diffuses across cleft and binds with receptors on sarcolemma - ACh binding leads to electrical events that ultimately generate an action potential through muscle fiber - ACh is quickly broken down by enzyme acetylcholinesterase, which stops contractions

The Nerve Stimulus and Events at the Neuromuscular Junction

Skeletal Muscle Fibers Myofibrils Myofilaments . Composed of protein myosin that contains two heavy and four light polypeptide chains • Heavy chains intertwine to form myosin tail • Light chains form myosin globular head - During contraction, heads link thick and thin filaments together, forming cross bridges • Myosins are offset from each other, resulting in staggered array of heads at different points along thick filament

Thick Filaments

Skeletal Muscle Fibers Myofibrils Myofilaments - Composed of fibrous protein actin • Actin is polypeptide made up of kidney-shaped G actin (globular) subunits - G actin subunits bears active sites for myosin head attachment during contraction • G actin subunits link together to form long, fibrous F actin (filamentous) • Two F actin strands twist together to form a thin filament - Tropomyosin and troponin: regulatory proteins bound to actin

Thin Filaments

. Burns • Entire thickness of skin involved (referred to as full-thickness burns) • Skin color turns gray-white, cherry red, or blackened • No edema is seen and area is not painful because nerve endings are destroyed • Skin grafting usually necessary

Third Degree

What are the two subdivisions in the ventral body cavity?

Thoracic Abdominopelvic

Two pleural cavities Each cavity surrounds one lung

Thoracic Cavity

Smooth Muscle • Smooth muscle varies in different organs by: 1. Fiber arrangement and organization 2. Innervation 3. Responsiveness to various stimuli • All smooth muscle is categorized as either: - Unitary - Multiunit • Unitary smooth muscle - Commonly referred to as visceral muscle - Found in all hollow organs except heart - Possess all common characteristics of smooth muscle: • Arranged in opposing (longitudinal and circular) sheets • Innervated by varicosities • Often exhibit spontaneous action potentials • Electrically coupled by gap junctions • Respond to various chemical stimuli • Multiunit smooth muscle - Located in large airways in lungs, large arteries, arrector pili muscles, and iris of eye - Very few gap junctions, and spontaneous depolarization is rare - Similar to skeletal muscle in some features • Consists of independent muscle fibers • Innervated by autonomic nervous system, forming motor units • Graded contractions occur in response to neural stimuli that involve recruitment - Different from skeletal muscle because, like unitary smooth muscle, it is controlled by autonomic nervous system and hormones

Types of Smooth Muscle

What are the two capsular ligaments restricted side to side movement in the elbow joint?

Ulnar collateral ligament Radial collateral ligament

Synovial Joints Movement . Movement in one plane

Uniaxial

. The only important unicellular glands are mucous cells and goblet cells . Found in epithelial linings of intestinal and respiratory tracts . All produce mucin, a sugar-protein that can dissolve in water to form mucus, a slimy protective, lubricating coating

Unicellular Exocrine Glands

What two ways is smooth muscle categorized?

Unitary Multiunit

Smooth Muscle Types of Smooth Muscle - Commonly referred to as visceral muscle - Found in all hollow organs except heart - Possess all common characteristics of smooth muscle: • Arranged in opposing (longitudinal and circular) sheets • Innervated by varicosities • Often exhibit spontaneous action potentials • Electrically coupled by gap junctions • Respond to various chemical stimuli

Unitary Smooth Muscle

Eliminates nitrogenous wastes from the body. Regulates water, electrolyte, and acid-base balance of the blood.

Urinary System

. Skin folds that overlap border of nail

Nail Folds

Burns are devastating and debilitating because of loss of fluids and electrolytes from the body. How do physicians estimate the extent of burn damage associated with such dangerous fluid loss? A. By using the "rule of nines" B. Through blood analysis C. By measuring urinary output and fluid intake D. By observing the tissues that are usually moist

• By embryonic week __, synovial joints resemble adult joints • Joint's size, shape, and flexibility modified by use - Active joints have _______ capsules and ligaments • Advancing years take toll on joints - Ligaments and tendons ________ and _______ - Intervertebral discs more likely to ________ - Most people in 70s have some degree of ___ • Full-range-of-motion exercise key to postponing joint problems

8 Thicker Shorten Weaken Herniate OA

A fibrous joint that is a peg-in-socket is called a ________ joint. A. Gomphosis B. Synchondrosis C. Syndesmosis D. Suture

A good example of a positive feedback mechanism would be ________. A. Enhancement of labor contractions B. Body temperature regulation C. Blood calcium level regulation D. Regulating glucose levels in the blood

A needle would pierce the epidermal layers of the forearm in which order? A. Corneum, granulosum, spinosum, basale B. Basale, spinosum, granulosum, corneum C. Granulosum, basale, spinosum, corneum D. Basale, spinosum, granulosum, lucidum, corneum

All of the following are factors that influence synovial joint stability EXCEPT? A. Number of bones in the joint B. Arrangement and tension of the muscles C. Structure and shape of the articulating bone D. Strength and tension of joint ligaments

An oblique cut is one that is cut ________. A. Diagonally between vertical and horizontal planes B. Vertically right and left C. Perpendicular to vertical and horizontal planes D. Horizontally superior and inferior

Articulations permitting only slight degrees of movement are ________. A. Amphiarthroses B. Diarthroses C. Synovial joints D. Synarthroses

Connective tissue matrix is composed of ________. A. Fibers and ground substance B. All organic compounds C. Ground substance and cells D. Cells and fibers

Creatine phosphate functions in the muscle cell by ________. A. Storing energy that will be transferred to ADP to resynthesize ATP B. Forming a chemical compound with actin C. Inducing a conformational change in the myofilaments D. Forming a temporary chemical compound with myosin

During muscle contraction, myosin cross bridges attach to which active sites? A. Actin filaments B. Z discs C. Myosin filaments D. Thick filaments

Histology would be best defined as a study of ________. A. Tissues B. Cell chemistry C. Cells D. The gross structures of the body

Most skeletal muscles contain ________. A. A mixture of fiber types B. A predominance of fast oxidative fibers C. Muscle fibers of the same type D. A predominance of slow oxidative fibers

Muscle tissue has all of the following properties except ________. A. Secretion B. Extensibility C. Contractility D. Excitability

Pointing the toes is an example of ________. A. Plantar flexion B. Pronation C. Protraction D. Circumduction

Rigor mortis occurs because ________. A. No ATP is available to release attached actin and myosin molecules B. Proteins are beginning to break down, thus preventing a flow of calcium ions C. The cells are dead D. Sodium ions leak into the muscle causing continued contractions

Rigor mortis occurs because ________. A. No ATP is available to release attached actin and myosin molecules B. The cells are dead C. Sodium ions leak into the muscle causing continued contractions D. Proteins are beginning to break down, thus preventing a flow of calcium ions

Select the correct statement regarding adipose tissue. A. Its primary function is nutrient storage. B. It is composed mostly of extracellular matrix. C. Mature adipose cells are highly mitotic. D. Most of the cell volume is occupied by the nucleus.

The central (Haversian) canal that runs through the core of each osteon is the site of ________. A. Blood vessels and nerve fibers B. Cartilage and interstitial lamellae C. Yellow marrow and spicules A. Adipose tissue and nerve fibers

The cruciate ligaments of the knee ________. A. Prevent hyperextension of the knee B. Attach to each other in their midportions C. Tend to run parallel to one another D. Are also called collateral ligaments

The dermis has two major layers. Which layer constitutes 80% of the dermis and is responsible for the tension lines in the skin? A. The reticular layer B. The papillary layer C. The subcutaneous layer D. The hypodermal laye

The dermis is a strong, flexible connective tissue layer. Which of the following cell types are likely to be found in the dermis? A. Fibroblasts, macrophages, and mast cells B. Goblet cells, parietal cells, and chondrocytes C. Osteoblasts, osteoclasts, and epithelial cells D. Monocytes, reticulocytes, and osteocytes

The first step in tissue repair involves ________. A. Inflammation B. Replacement of destroyed tissue by the same kind of cells C. Proliferation of fibrous connective tissue D. Formation of scar tissue

The parietal pleura would represent a serous membrane ________. A. Lining the thoracic cavity B. Lining the abdominal cavity C. Covering the heart D. Covering individual lungs

The shape of the external ear is maintained by ________. A. Elastic cartilage B. Adipose tissue C. Hyaline cartilage D. Fibrocartilage

The structure of bone tissue suits the function. Which of the following bone tissues is adapted to support weight and withstand torsion stresses? A. Compact bone B. Trabecular bone C. Irregular bone D. Spongy bone

The study of large body structures, visible to the naked eye, such as the heart is called ________ anatomy. A. Gross B. Microscopic C. Systemic D. Developmental

Vernix caseosa is a ________. A. Whitish material produced by fetal sebaceous glands B. Coat of fine, downy hair on the heads of balding men C. Substance contributing to acne during adolescence D. Cheesy-looking sudoriferous secretion on the skin of newborns

What are menisci? A. Semilunar cartilage pads B. Tendon sheaths C. Cavities lined with cartilage D. Small sacs containing synovial fluid

Which muscle cells have the greatest ability to regenerate? A. Smooth B. No muscle can regenerate C. Cardiac D. Skeletal

Which of the following is NOT found in cartilage but is found in bone? A. Blood vessels B. Living cells C. Lacunae D. Organic fibers

Which of the following is a bone marking name that indicates an armlike bar of bone? A. Ramus B. Foramen C. Meatus D. Epicondyle E. Fossa

Which of the following is a factor that affects the velocity and duration of muscle contraction? A. Load on the fiber B. Size of the muscle fibers stimulated C. Muscle length D. Number of muscle fibers stimulated

Which of the following is a single-celled layer of epithelium that forms the lining of serous membranes? A. Simple squamous B. Simple cuboidal C. Simple columnar D. Pseudostratified columnar

Which of the following is not a factor that contributes to keeping the articular surfaces of diarthroses in contact? A. Number of bones in the joint B. Strength and tension of joint ligaments C. Structure and shape of the articulating bone D. Arrangement and tension of the muscles

Which of the following is not a function of the skeletal system? A. Communication B. Support C. Storage of minerals D. Production of blood cells (hematopoiesis)

Which of the following is true about smooth muscle? A. Certain smooth muscle cells can actually divide to increase their numbers. B. Smooth muscle, in contrast to skeletal muscle, cannot synthesize or secrete any connective tissue elements. C. Smooth muscle has well-developed T tubules at the site of invagination. D. Smooth muscle cannot stretch as much as skeletal muscle

Which of the following statements is true? A. Striated muscle cells are long and cylindrical with many nuclei. B. Smooth muscle cells have T tubules. C. Cardiac muscle cells have many nuclei. D. Cardiac muscle cells are found in the heart and large blood vessels.

Which of the following surrounds the individual muscle cell? A. Endomysium B. Epimysium C. Fascicle D. Perimysium

Which one of the following systems responds fastest to environmental stimuli? A. Nervous B. Lymphatic C. Immune D. Muscular

Which structure allows the diaphysis of the bone to increase in length until early childhood? A. Epiphyseal plate B. Lacuna C. Osteon D. Epiphyseal line

________ epithelium appears to have two or three layers of cells, but all the cells are in contact with the basement membrane. A. Pseudostratified columnar B. Stratified columnar C. Stratified cuboidal D. Transitional

ABCD Rule . The two sides of the pigmented area do not match

A Asymmetry

Skeletal Muscle Fibers Myofibrils Striations . Dark regions

A Bands

• A: asymmetry; the two sides of the pigmented area do not match • B: border irregularity; exhibits indentations • C: color; contains several colors (black, brown, tan, sometimes red or blue) • D: diameter; larger than 6 mm (size of pencil eraser)

ABCD Rule

Abdominal cavity Contains stomach, intestines, spleen, and liver

Abdominopelvic Cavity

Angular Movements . Movement along frontal plane, away from the midline

Abduction

. Low pH of skin retards bacterial multiplication

Acid Mantle

Skeletal Muscle Fibers Myofibrils Myofilaments . Thin filaments • Extend across I band and partway in A band • Anchored to Z discs

Actin Myofilaments

Muscle Fiber Contraction . An electrical current, must be generated in sarcolemma

Action Potential

Aerobic (Endurance) Exercise • Aerobic (endurance) exercise, such as jogging, swimming, biking leads to increased: • Muscle capillaries • Number of mitochondria • Myoglobin synthesis - Results in greater endurance, strength, and resistance to fatigue - May convert fast glycolytic fibers into fast oxidative fibers • Resistance exercise (typically anaerobic), such as weight lifting or isometric exercises, leads to - Muscle hypertrophy • Due primarily to increase in fiber size - Increased mitochondria, myofilaments, glycogen stores, and connective tissue - Increased muscle strength and size • Muscles must be active to remain healthy • Disuse atrophy (degeneration and loss of mass) - Due to immobilization or loss of neural stimulation - Can begin almost immediately. • Muscle strength can decline 5% per day • Paralyzed muscles may atrophy to one-fourth initial size • Fibrous connective tissue replaces lost muscle tissue • Rehabilitation is impossible at this point

Adaptation to Exercise

Angular Movements . Movement along frontal plane, toward the midline

Adduction

• White fat - Similar to areolar tissue but greater nutrient storage - Cells are called adipocytes - Scanty matrix - Richly vascularized - Functions in shock absorption, insulation, and energy storage • Brown fat - Use lipid fuels to heat bloodstream rather than to produce ATP, as does white fat Description:Matrix as in areolar, but very sparse; closely packed adipocytes, or fat cells, have nucleus pushed to the side by large fat droplet. Function:Provides reserve food fuel; insulates against heat loss; supports and protects organs. Location:Under skin in subcutaneous tissue; around kidneys and eyeballs; within abdomen; in breasts.

Adipose Tissue

What are the two ways to use energy systems during sports?

Aerobi Endurance Anaerobic Threshold

Energy for Contraction and ATP Energy Systems Used During Sports • Length of time muscle contracts using aerobic pathways - Light-to-moderate activity, which can continue for hours

Aerobic Endurance

Adaptation to Exercise . Such as jogging, swimming, biking leads to increased: • Muscle capillaries • Number of mitochondria • Myoglobin synthesis - Results in greater endurance, strength, and resistance to fatigue - May convert fast glycolytic fibers into fast oxidative fibers

Aerobic Exercise

Energy for Contraction and ATP - Produces 95% of ATP during rest and light-to-moderate exercise • Slower than anaerobic pathway - Consists of series of chemical reactions that occur in mitochondria and require oxygen • Breaks glucose into CO2, H2O, and large amount ATP (32 can be produced) - Fuels used include glucose from glycogen stored in muscle fiber, then bloodborne glucose, and free fatty acids • Fatty acids are main fuel after 30 minutes of exercise

Aerobic Respiration

• Most widely distributed CT • Supports and binds other tissues • Universal packing material between other tissues • Contains fibroblasts that secrete loose arrangement of mostly collagen fibers • Loose fibers allow for increased ground substance, which can act as water reservoir by holding more interstitial fluid • Macrophages and fat cells are contained in spaces Description: Gel-like matrix with all three fiber types; cells: fibroblasts, macrophages, mast cells, and some white blood cells. Function: Wraps and cushions organs; its macrophages phagocytize bacteria; plays important role in inflammation; holds and conveys tissue fluid. Location: Widely distributed under epithelia of body, e.g., forms lamina propria of mucous membranes; packages organs; surrounds capillaries. - Adipose tissue • White fat - Similar to areolar tissue but greater nutrient storage - Cells are called adipocytes - Scanty matrix - Richly vascularized - Functions in shock absorption, insulation, and energy storage • Brown fat - Use lipid fuels to heat bloodstream rather than to produce ATP, as does white fat

Aerolar Connective Tissue

• _____ ______ - Epidermal replacement slows; skin becomes thin, dry, and itchy (decreased sebaceous gland activity) - Subcutaneous fat and elasticity decrease, leading to cold intolerance and wrinkles - Increased risk of cancer due to decreased numbers of melanocytes and dendritic cells - Hair thinning • Ways to delay _______: - UV protection, good nutrition, lots of fluids, good hygiene

Aging skin Aging

Hair thinning in both sexes after age 40

Alopecia

Slightly movable joints

Amphiarthroses

Energy for Contraction and ATP - ATP can also be generated by breaking down and using energy stored in glucose • Glycolysis: first step in glucose breakdown - Does not require oxygen - Glucose is broken into 2 pyruvic acid molecules - 2 ATPs are generated for each glucose broken down • Low oxygen levels prevent pyruvic acid from entering aerobic respiration phase - Normally, pyruvic acid enters mitochondria to start aerobic respiration phase; however, at high intensity activity, oxygen is not available • Bulging muscles compress blood vessels, impairing oxygen delivery - In the absence of oxygen, referred to as anaerobic glycolysis, pyruvic acid is converted to lactic acid - Lactic acid • Diffuses into bloodstream • Used as fuel by liver, kidneys, and heart • Converted back into pyruvic acid or glucose by liver - Anaerobic respiration yields only 5% as much ATP as aerobic respiration, but produces ATP 2½ times faster . Muscle Fatigue • Physiological inability to contract despite continued stimulation • Usually occurs when there are ionic imbalances - Levels of K+, Ca2+, Pi can interfere with E-C coupling - Prolonged exercise may also damage SR and interferes with Ca2+ regulation and release • Lack of ATP is rarely a reason for fatigue, except in severely stressed muscles • For a muscle to return to its pre-exercise state: - Oxygen reserves are replenished - Lactic acid is reconverted to pyruvic acid - Glycogen stores are replaced - ATP and creatine phosphate reserves are resynthesized • All replenishing steps require extra oxygen, so this is referred to as excess postexercise oxygen consumption (EPOC) - Formerly referred to as "oxygen debt"

Anaerobic Pathway Glycolysis and Lactic Acid Formation

Energy for Contraction and ATP Energy Systems Used During Sports • Point at which muscle metabolism converts to anaerobic pathway

Anaerobic Threshold

-Body erect, feet slightly apart, palms facing forward with thumbs pointing away from body

Anatomical Position

• In women, ovaries and adrenal glands produce small amounts of androgens (male sex hormones), but tumors on these organs can cause abnormally large amounts of _______ • Can result in excessive hairiness, called ________, as well as other signs of masculinization • Treatment is surgical removal of tumors

Androgens Hirsutism

. Synovial Joints Movement - Increase or decrease angle between two bones - Movement along sagittal plane - Angular movements include: • Flexion: decreases the angle of the joint • Extension: increases the angle of the joint - Hyperextension: movement beyond the anatomical position - Abduction: movement along frontal plane, away from the midline - Adduction: movement along frontal plane, toward the midline - Circumduction • Involves flexion, abduction, extension, and adduction of limb • Limb describes cone in space

Angular Movements

Ventral Toward or at the front of the body

ACL

Anterior Cruciate Ligament

• Attaches to anterior tibia • Prevents forward sliding of tibia and stops hyperextension of knee

Anterior Cruciate Ligament

What two things are supposed to help anterior-posterior displacement?

Anterior cruciate ligament Posterior cruciate ligament

Elbow Joint . Surrounds head of radius

Anular Ligament

Upper free side, is exposed to surface or cavity Most _____ ______ are smooth, but some have specialized fingerlike projections called microvilli

Apical Surfaces

Multicellular Exocrine Glands Accumulate products within, but only apex ruptures; whether this type exists in humans is controversial (maybe mammary cells?)

Apocrine

• Confined to axillary and anogenital areas • Secrete viscous milky or yellowish sweat that contains fatty substances and proteins - Bacteria break down sweat, leading to body odor • Larger than eccrine sweat glands with ducts emptying into hair follicles • Begin functioning at puberty - Function unknown but may act as sexual scent gland • Modified ______ _______ - Ceruminous glands: lining of external ear canal; secrete cerumen (earwax) - Mammary glands: secrete milk

Apocrine Sweat Glands

Controlled cell death

Apoptosis

• Cells change by going through ______ (controlled cell death) - Dead cells slough off as dandruff and dander - Humans can shed ~_____ cells every minute

Apoptosis 50000

Limbs (legs and arms)

Appendicular

•Bones of upper and lower limbs •Girdles attaching limbs to axial skeleton

Appendicular Skeleton

•Cartilage-forming cells in perichondrium secrete matrix against external face of existing cartilage -New matrix laid down on surface of cartilage

Appositional Growth

What are the two ways cartilage can grow?

Appositional Interstitial

- Specific pressure of air is needed for adequate breathing and gas exchange in lungs

Appropriate Atmospheric Pressure

Knee Joint . Reinforces joint capsule posteriorly

Arcuate Popliteal Ligament

. Small band of smooth muscle attached to follicle - Responsible for "goose bumps"

Arrector Pilli

- >100 different types of inflammatory or degenerative diseases that damage joints - Most widespread crippling disease in the U.S. - Symptoms: pain, stiffness, and swelling of joint - Acute forms: caused by bacteria, treated with antibiotics - Chronic forms: osteoarthritis, rheumatoid arthritis, and gouty arthritis - OA is usually part of normal aging process - Joints may be stiff and make crunching noise referred to as crepitus, especially upon rising - Treatment: moderate activity, mild pain relievers, capsaicin creams • Glucosamine, chondroitin sulfate, and nutritional supplements not effective • Rheumatoid arthritis (RA) - Chronic, inflammatory, autoimmune disease of unknown cause • Immune system attacks own cells - Usually arises between ages 40 and 50, but may occur at any age; affects three times as many women as men - Signs and symptoms include joint pain and swelling (usually bilateral), anemia, osteoporosis, muscle weakness, and cardiovascular problems - RA begins with inflammation of synovial membrane (synovitis) of affected joint - Inflammatory blood cells migrate to joint, release inflammatory chemicals that destroy tissues - Synovial fluid accumulates, causing joint swelling - Inflamed synovial membrane thickens into abnormal pannus tissue that clings to articular cartilage - Pannus erodes cartilage, scar tissue forms and connects articulating bone ends (ankylosis) - Treatment includes steroidal and nonsteroidal anti-inflammatory drugs to decrease pain and inflammation - Disruption of destruction of joints by immune system • Immune suppressants slow autoimmune reaction • Some agents target tumor necrosis factor to block action of inflammatory chemicals - Can replace joint with prosthesis • Gouty _______ - Deposition of uric acid crystals in joints and soft tissues, followed by inflammation - More common in men - Typically affects joint at base of great toe - In untreated gouty arthritis, bone ends fuse and immobilize joint - Treatment: drugs, plenty of water, avoidance of alcohol and foods high in purines, such as liver, kidneys, and sardines

Arthritis

• Osteoarthritis (OA) - Most common type of _______ - Irreversible, degenerative ("wear-and-tear") ________ - May reflect excessive release of enzymes that break down articular cartilage • Cartilage is broken down faster than it is replaced • Bone spurs (osteophytes) may form from thickened ends of bones - By age 85, half of Americans develop OA, more women than men

Arthritis

What are the different types of inflammatory and degenerative conditions?

Arthritis Tendonitis Bursitis

. Two layers thick • External fibrous layer: dense irregular connective tissue • Inner synovial membrane: loose connective tissue that makes synovial fluid

Articular Capsule

. Consists of hyaline cartilage covering ends of bones • Prevents crushing of bone ends

Articular Cartilage

• Fibrocartilage separates articular surfaces to improve "fit" of bone ends, stabilize joint, and reduce wear and tear

Articular Discs

What are the six general features of synovial joints?

Articular cartilage Joint cavity Articular capsule Synovial fluid Different types of reinforcing ligaments Nerves and blood vessels

Distortions

Artifacts

Skeletal Muscle Tissue • Muscles span joints and attach to bones • Muscles attach to bone in at least two places - Insertion: attachment to movable bone - Origin: attachment to immovable or less movable bone • ________ can be direct or indirect - Direct (fleshy): epimysium fused to periosteum of bone or perichondrium of cartilage - Indirect: connective tissue wrappings extend beyond muscle as ropelike tendon or sheetlike aponeurosis

Attachments

Receives nutrients from membrane surrounding it (perichondrium)

Avascular

• _____ _____ loses ability to divide as we age, so injuries heal slowly - Common in people with _____ injuries • Later in life, cartilage can calcify or ossify (become bony), causing _______ to die

Avascular cartilage Sports Chondrocytes

Head, neck and trunk

Axial

What are the two groups based on location in bones?

Axial Appendicular

What are the two major divisions of the body?

Axial Appendicular

•Long axis of body •Skull, vertebral column, rib cage

Axial Skeleton

Muscle Fiber Contraction The Nerve Stimulus and Events at the Neuromuscular Junction . (end of axon) and muscle fiber are separated by gel-filled space called synaptic cleft

Axon

A fracture in the shaft of a bone would be a break in the ________. A. Articular cartilage B. Diaphysis C. Epiphysis D. Metaphysis

A light skinned person may appear pink when they become over heated. The best explanation for this is ________. A. Blood flow has increased to the sweat glands in order to increased their metabolic activity B. The blood vessels of the dermis have undergone vasodilation, bringing a greater volume of blood to the skin C. The melanocytes are responding to the heat of the sun and change the appearance of the skin with increased production D. The heart is pumping faster because the person was probably exercising

A needle would pierce the epidermal layers of the forearm in which order? A. Basale, spinosum, granulosum, corneum B. Corneum, granulosum, spinosum, basale C. Granulosum, basale, spinosum, corneum D. Basale, spinosum, granulosum, lucidum, corneum

Articular cartilage found at the ends of the long bones serves to ________. A. Attach tendons B. Provide a smooth surface at the ends of synovial joints C. Produce red blood cells (hemopoiesis) D. Form the synovial membrane

Bones are constantly undergoing resorption (breaking bone down) for various reasons. Which of the following cells accomplishes this process? A. Osteoblast B. Osteoclast C. Osteocyte D. Stem cell

Connective tissue sacs lined with synovial membranes that act as cushions in places where friction develops are called ________. A. Tendons B. Bursae C. Menisci D. Ligaments

Myoglobin ________. A. Is a protein involved in the direct phosphorylation of ADP B. Stores oxygen in muscle cells C. Produces the end plate potential D. Breaks down glycogen

Performing "jumping jacks" requires ________. A. Inversion and eversion B. Abduction and adduction C. Pronation and supination D. Flexion and extention

Place the following in correct sequence from simplest to most complex: 1. molecules 2. atoms 3. tissues 4. cells 5. organs A. 1-2-4-3-5 B. 2-1-4-3-5 C. 1-2-3-4-5 D. 2-1-3-4-5

The anatomical position is characterized by all of the following except ________. A. Arms at sides B. Palms turned posteriorly C. Thumbs pointed laterally D. Body erect

The contractile units of skeletal muscles are ________. A. Mitochondria B. Myofibrils C. Microtubules D. T tubules

The dorsal body cavity is the site of which of the following? A. Liver B. Brain C. Lungs D. Intestines

The first step in tissue repair involves ________. A. Formation of scar tissue B. Inflammation C. Replacement of destroyed tissue by the same kind of cells D. Proliferation of fibrous connective tissue

The friction ridges seen in finger, palm and foot prints are different among various people but very similar between identical twins. This evidence suggests which of the following? A. That friction ridges aid in griping. B. That friction ridges are genetically determined. C. That friction ridges allow for better tactile sensation. D. That friction ridges change over time

The single most important risk for skin cancer is ________ A. Race B. Overexposure to UV radiation C. Genetics D. Use of farm chemicals

The single most important risk for skin cancer is ________. A. Use of farm chemicals B. Overexposure to UV radiation C. Race D. Genetics

The terms inversion and eversion pertain only to the ________. A. Arms B. Feet C. Hands D. Hands and the feet

What are menisci (articular discs)? A. Tendon sheaths B. Wedges of fibrocartilage that partially or completely divide the synovial cavity C. Small sacs containing synovial fluid D. Cavities lined with cartilage

What does excess postexercise oxygen consumption represent? A. The amount of oxygen equal to the oxygen already used B. The difference between the amount of oxygen needed for totally aerobic muscle activity and the amount actually used C. Amount of oxygen needed for aerobic activity to accomplish the same amount of work D. The amount of oxygen taken into the body immediately after the exertion

What is moving a limb away from the median plane of the body along the frontal plane called? A. Dorsiflexion B. Abduction C. Inversion D. Adduction

What is the role of tropomyosin in skeletal muscles? A. Tropomyosin is the chemical that activates the myosin heads. B. Tropomyosin serves as a contraction inhibitor by blocking the myosin binding sites on the actin molecules. C. Tropomyosin is the receptor for the motor neuron neurotransmitter. D. Tropomyosin serves as a contraction inhibitor by blocking the actin binding sites on the myosin molecules.

What kind of tissue is the forerunner of long bones in the embryo? A. Fibrocartilage B. Hyaline cartilage C. Elastic connective tissue D. Dense fibrous connective tissue

What tissue has lacunae, calcium salts, and blood vessels? A. Areolar tissue B. Osseous tissue C. Cartilage tissue D. Fibrocartilaginous tissue

When a muscle is unable to respond to stimuli temporarily, it is in which of the following periods? A. Fatigue period B. Refractory period C. Latent period D. Relaxation period

Which cells are commonly found wedged between simple columnar epithelial cells? A. Mast cells B. Goblet cells C. Macrophages D. Cilia

Which glands produce ear wax? A. Merocrine glands B. Ceruminous glands C. Apocrine glands D. Eccrine glands

Which ligament of the knee initiates the knee-jerk reflex when tapped? A. The extracapsular ligament B. The patellar ligament C. The lateral patellar retinacula D. The medial patellar retinacula

Which of the following cells and their functions are correctly matched? A. Melanocytes — protects cells in the stratum corneum from damaging effects of sun's rays B. Dendritic cells — activate the immune system C. Tactile cells — protection D. Keratinocytes — provide sense of touch and pressure

Which of the following cells and their functions are correctly matched? A. Tactile cells — protection B. Dendritic cells — activate the immune system C. Keratinocytes — provide sense of touch and pressure D. Melanocytes —protects cells in the stratum corneum from damaging effects of sun's rays

Which of the following epithelia forms the walls of the air sacs across which gas exchange occurs in the lungs? A. Pseudostratified columnar B. Simple squamous C. Simple cuboidal D. Simple columnar

Which one of the following systems responds fastest to environmental stimuli? A. Lymphatic B. Nervous C. Muscular D. Immune

Wolff's law is concerned with ________. A. Vertical growth of bones being dependent on age B. The thickness and shape of a bone being dependent on stresses placed upon it C. The diameter of the bone being dependent on the ratio of osteoblasts to osteoclasts D. The function of bone being dependent on shape

Yellow bone marrow contains a large percentage of ________. A. Blood-forming cells B. Fat C. Elastic tissue D. Sharpey's fibers

________ epithelium appears to have two or three layers of cells, but all the cells are in contact with the basement membrane. A. Transitional B. Pseudostratified columnar C. Stratified cuboidal D. Stratified columnar

ABCD Rule . Exhibits indentations

B Border Irregularity

- Genetically determined and sex-influenced condition - Male pattern _______ caused by follicular response to DHT (dihydrotestosterone)

Baldness

- Least malignant and most common - Stratum basale cells proliferate and slowly invade dermis and hypodermis - Cured by surgical excision in 99% of cases

Basal Carcinoma

Lower attached side, faces inwards toward body Attaches to basal lamina, an adhesive sheet that holds _______ ______ of epithelial cells to underlying cells

Basal Surface

What are three major types of skin cancer?

Basal cell carcinoma Squamous cell carcinoma Melanoma

Made up of basal and reticular lamina Reinforces epithelial sheet Resists stretching and tearing Defines epithelial boundary

Basement Membrane

Cancerous epithelial cells are not contained by the ______ ______ _______ They penetrate the boundary and invade underlying tissues, resulting in spread of _____

Basement membrane boundary Cancer

Synovial Joints Movement . Movement in two planes

Biaxial

- Epidermis contains phagocytic cells • Dendritic cells of epidermis engulf foreign antigens (invaders) and present to white blood cells, activating the immune response - Dermis contains macrophages • Macrophages also activate immune system by presenting foreign antigens to white blood cells - DNA can absorb harmful UV radiation, converting it to harmless heat

Biological Barrier

. Decrease osteoclast activity and number • Partially reverse osteoporosis in spine

Bisphosphonates

• Immature form of cell that actively secretes ground substance and ECM fibers • Fibroblasts found in connective tissue proper • Chondroblasts found in cartilage • Osteoblasts found in bone • Hematopoietic stem cells in bone marrow

Blast Cells

- Most atypical connective tissue because it is fluid • Consists of cells surrounded by matrix (plasma) - Red blood cells are most common cell type - Also contains white blood cells and platelets - Fibers are soluble proteins that precipitate during blood clotting - Functions in transport and in carrying nutrients, wastes, gases, and other substances Description:Red and white blood cells in a fluid matrix (plasma). Function:Transport respiratory gases, nutrients, wastes, and other substances Location:Contained within blood vessels.

Blood

• New bone matrix is deposited by osteoblasts • Osteoid seam: band of unmineralized bone matrix that marks area of new matrix • Calcification front: abrupt transition zone between osteoid seam and older mineralized bone • Trigger for deposit not confirmed but may include: - Mechanical signals - Increased concentrations of calcium and phosphate ions for hydroxyapatite formation - Matrix proteins that bind and concentrate calcium - Appropriate amount of enzyme alkaline phosphatase for mineralization

Bone Deposit

• Imbalances between bone deposit and bone resorption underlie nearly every disease that affects the human skeleton. • Three major ____ _____: - Osteomalacia and rickets - Osteoporosis - Paget's disease • Osteomalacia - Bones are poorly mineralized - Osteoid is produced, but calcium salts not adequately deposited - Results in soft, weak bones - Pain upon bearing weight • Rickets (osteomalacia of children) - Results in bowed legs and other bone deformities because bones ends are enlarged and abnormally long - Cause: vitamin D deficiency or insufficient dietary calcium • Osteoporosis is a group of diseases in which bone resorption exceeds deposit • Matrix remains normal, but bone mass declines - Spongy bone of spine and neck of femur most susceptible • Vertebral and hip fractures common • Risk factors for osteoporosis - Most often aged, postmenopausal women • Affects 30% of women aged 60-70 years and 70% by age 80 • 30% of Caucasian women will fracture bone because of osteoporosis • Estrogen plays a role in bone density, so when levels drop at menopause, women run higher risk - Men are less prone due to protection by the effects of testosterone • Additional risk factors for osteoporosis: - Petite body form - Insufficient exercise to stress bones - Diet poor in calcium and protein - Smoking - Hormone-related conditions • Hyperthyroidism • Low blood levels of thyroid-stimulating hormone • Diabetes mellitus - Immobility - Males with prostate cancer taking androgen-suppressing drugs • Treating osteoporosis - Traditional treatments • Calcium • Vitamin D supplements • Weight-bearing exercise • Hormone replacement therapy - Slows bone loss but does not reverse it - Controversial because of increased risk of heart attack, stroke, and breast cancer • Other drugs for osteoporosis: - Bisphosphonates: decrease osteoclast activity and number • Partially reverse osteoporosis in spine - Selective estrogen receptor modulators: mimic estrogen without targeting breast and uterus - Denosumab • Monoclonal antibody shown to reduce fractures in men with prostate cancer • Improves bone density in elderly • Preventing osteoporosis - Plenty of calcium in diet in early adulthood - Reduce consumption of carbonated beverages and alcohol • Leach minerals from bone, so decrease bone density - Plenty of weight-bearing exercise • Increases bone mass above normal for buffer against age-related bone loss . Paget's Disease • Excessive and haphazard bone deposit and resorption cause bone to be made fast and poorly - Called Pagetic bone - Very high ratio of spongy to compact bone and reduced mineralization • Usually occurs in spine, pelvis, femur, and skull • Rarely occurs before age 40 • Cause unknown: possibly viral • Treatment includes calcitonin and bisphosphonates

Bone Diseases

-Flat cells on bone surfaces believed to also help maintain matrix (along with osteocytes) -On external bone surface, lining cells are called periosteal cells -On internal surfaces, they are called endosteal cells

Bone Lining Cells

-Sites of muscle, ligament, and tendon attachment on external surfaces -Areas involved in joint formation or conduits for blood vessels and nerves -Three types of _______: •Projection: outward bulge of bone -May be due to increased stress from muscle pull or is a modification for joints •Depression: bowl- or groove-like cut-out that can serve as passageways for vessels and nerves, or plays a role in joints •Opening: hole or canal in bone that serves as passageways for blood vessels and nerves

Bone Markings

- Begins during bony callus formation and continues for several months - Excess material on diaphysis exterior and within medullary cavity is removed - Compact bone is laid down to reconstruct shaft walls - Final structure resembles original structure • Responds to same mechanical stressors

Bone Remodeling

• About 5-7% of bone mass is recycled each week - Spongy bone replaced ~ every 3-4 years - Compact bone replaced ~ every 10 years • Bone remodeling consists of both bone deposit and bone resorption - Occurs at surfaces of both periosteum and endosteum - Remodeling units: packets of adjacent osteoblasts and osteoclasts coordinate • New bone matrix is deposited by osteoblasts • Osteoid seam: band of unmineralized bone matrix that marks area of new matrix • Calcification front: abrupt transition zone between osteoid seam and older mineralized bone • Trigger for deposit not confirmed but may include: - Mechanical signals - Increased concentrations of calcium and phosphate ions for hydroxyapatite formation - Matrix proteins that bind and concentrate calcium - Appropriate amount of enzyme alkaline phosphatase for mineralization • Resorption is function of osteoclasts - Dig depressions or grooves as they break down matrix - Secrete lysosomal enzymes and protons (H+) that digest matrix - Acidity converts calcium salts to soluble forms • Osteoclasts also phagocytize demineralized matrix and dead osteocytes - Digested products are transcytosed across cell and released into interstitial fluid and then into blood - Once resorption is complete, osteoclasts undergo apoptosis • Osteoclast activation involves PTH (parathyroid hormone) and immune T cell proteins • Remodeling occurs continuously but is regulated by genetic factors and two control loops 1. Hormonal controls • Negative feedback loop that controls blood Ca2+ levels • Calcium functions in many processes, such as nerve transmission, muscle contraction, blood coagulation, gland and nerve secretions, as well as cell division • 99% of 1200-1400 gms of calcium are found in bone • Intestinal absorption of Ca2+ requires vitamin D 2. Response to mechanical stress 1. Hormonal controls - Parathyroid hormone (PTH): produced by parathyroid glands in response to low blood calcium levels • Stimulates osteoclasts to resorb bone • Calcium is released into blood, raising levels • PTH secretion stops when homeostatic calcium levels are reached - Calcitonin: produced by parafollicular cells of thyroid gland in response to high levels of blood calcium levels • Effects are negligible, but at high pharmacological doses it can lower blood calcium levels temporarily- Other hormones play a role in bone density and turnover • Leptin - Hormone released by adipose tissue - May play role in bone density regulation by inhibiting osteoblasts • Serotonin - Neurotransmitter regulates mood and sleep; also interferes with osteoblast activity - Most serotonin made in gut - Secreted into blood after a meal - May inhibit bone turnover after a meal, so bone calcium is locked in when new calcium is flooding into bloodstream 2. Response to mechanical stress - Bones reflect stresses they encounter • Bones are stressed when weight bears on them or muscles pull on them - Wolf's law states that bones grow or remodel in response to demands placed on them • Stress is usually off center, so bones tend to bend • Bending compresses one side, stretches other side - Diaphysis is thickest where bending stresses are greatest - Bone can be hollow because compression and tension cancel each other out in center of bone - Wolf's law also explains: • Handedness (right- or left-handed) results in thicker and stronger bone of the corresponding upper limb • Curved bones are thickest where most likely to buckle • Trabeculae form trusses along lines of stress • Large, bony projections occur where heavy, active muscles attach - Weight lifters have enormous thickenings at muscle attachment sites of most used muscles • Bones of fetus and bedridden people are featureless because of lack of stress on bones • Mechanical stress causes remodeling by producing electrical signals when bone is deformed - Compressed and stretched regions are oppositely charged - Compression/tension changes fluid flows within canaliculi, which may also stimulate remodeling • Hormonal controls determine whether and when remodeling occurs in response to changing blood calcium levels, but mechanical stress determines where it occurs

Bone Remodeling

• Fractures are breaks - During youth, most fractures result from trauma - In old age, most result from weakness of bone due to bone thinning • Three "either/or" fracture classifications - Position of bone ends after fracture • Nondisplaced: ends retain normal position • Displaced: ends are out of normal alignment - Completeness of break • Complete: broken all the way through • Incomplete: not broken all the way through - Whether skin is penetrated • Open (compound): skin is penetrated • Closed (simple): skin is not penetrated • Can also be described by location of fracture, external appearance, and nature of break • Treatment involves reduction, the realignment of broken bone ends - Closed reduction: physician manipulates to correct position - Open reduction: surgical pins or wires secure ends - Immobilization of bone by cast or traction is needed for healing • Time needed for repair depends on break severity, bone broken, and age of patient • Repair involves four major stages: 1. Hematoma formation 2. Fibrocartilaginous callus formation 3. Bony callus formation 4. Bone remodeling 1. Hematoma formation - Torn blood vessels hemorrhage, forming mass of clotted blood called a hematoma - Site is swollen, painful, and inflamed 2. Fibrocartilaginous callus formation - Capillaries grow into hematoma - Phagocytic cells clear debris - Fibroblasts secrete collagen fibers to span break and connect broken ends - Fibroblasts, cartilage, and osteogenic cells begin reconstruction of bone • Create cartilage matrix of repair tissue • Osteoblasts form spongy bone within matrix - This mass of repair tissue is called fibrocartilaginous callus 3. Bony callus formation - Within one week, new trabeculae appear in fibrocartilaginous callus - Callus is converted to bony (hard) callus of spongy bone - Bony callus formation continues for about 2 months until firm union forms 4. Bone remodeling - Begins during bony callus formation and continues for several months - Excess material on diaphysis exterior and within medullary cavity is removed - Compact bone is laid down to reconstruct shaft walls - Final structure resembles original structure • Responds to same mechanical stressors

Bone Repair

• ________ is function of osteoclasts - Dig depressions or grooves as they break down matrix - Secrete lysosomal enzymes and protons (H+) that digest matrix - Acidity converts calcium salts to soluble forms • Osteoclasts also phagocytize demineralized matrix and dead osteocytes - Digested products are transcytosed across cell and released into interstitial fluid and then into blood - Once ________ is complete, osteoclasts undergo apoptosis • Osteoclast activation involves PTH (parathyroid hormone) and immune T cell proteins

Bone Resorption

What does bone remodeling consist of?

Bone deposit Bone resorption

• Bags of synovial fluid that act as lubricating "ball bearing" - Not strictly part of synovial joints, but closely associated • Bursae: reduce friction where ligaments, muscles, skin, tendons, or bones rub together • Tendon sheaths: elongated bursae wrapped completely around tendons subjected to friction

Bursae and Tendon Sheaths

- Inflammation of bursa, usually caused by blow or friction - Treated with rest and ice and, if severe, anti-inflammatory drugs

Bursitis

A ciliated version of pseudostratified columnar epithelium containing mucus-secreting goblet cells ________. A. Is found in some of the larger glands B. Is more durable than all other epithelia C. Lines most of the respiratory tract D. Aids in digestion

A fibrous joint that is a peg-in-socket is called a ________ joint. A. Synchondrosis B. Suture C. Gomphosis D. Syndesmosis

A structure that is composed of two or more tissue types that work together to perform specific functions for the body is a(n) ________. A. Complex tissue B. Complex cell C. Organ D. Organ system

A surgeon opens her patient by cutting the integument parallel to the cleavage lines of the dermis (tension lines). This will result in ________. A. Greater chance of infection B. Slowed healing and grater scaring C. Faster healing of the skin and less scaring D. Less chance for infection

Antibiotic treatment would be recommended for ________. A. Rheumatoid arthritis B. Gout C. Lyme disease D. Osteoarthritis

At what age do bones reach their peak density? A. Early childhood B. Late adulthood C. Early adulthood D. At birth

Baseball pitchers often require "Tommy John" surgery to repair damage to their elbow. Which ligament would this surgery target? A. Acetabular labrum B. Lateral ligament C. Ulnar collateral ligament D. Anular ligament

Bending your head back until it hurts is an example of ________. A. Flexion B. Circumduction C. Hyperextension D. Extension

Connective tissue sacs lined with synovial membrane that act as cushions in places where friction develops are called ________. A. Ligaments B. Tendons C. Bursae D. Menisci

During muscle contraction, myosin cross bridges attach to which active sites? A. Thick filaments B. Myosin filaments C. Actin filaments D. Z discs

During vigorous exercise, there may be insufficient oxygen available to completely break down pyruvic acid for energy. As a result, the pyruvic acid is converted to ________. A. Stearic acid B. Hydrochloric acid C. Lactic acid D. A strong base

Generally what is the result of the negative feedback process? A. To keep the body's blood sugar level high B. To regulate excretion via the kidneys C. To maintain homeostasis D. To control body movement

Histology would be best defined as a study of ________. A. Cell chemistry B. The gross structures of the body C. Tissues D. Cells

Homeostasis is the condition in which the body maintains ________. A. A dynamic state within an unlimited range, depending on circumstances B. A static state with no deviation from preset points C. A relatively stable internal environment, within limits D. The lowest possible energy usage

Myoglobin ________. A. Breaks down glycogen B. Produces the end plate potential C. Stores oxygen in muscle cells D. Is a protein involved in the direct phosphorylation of ADP

Pointing the toes is an example of ________. A. Circumduction B. Pronation C. Plantar flexion D. Protraction

Saddle joints have concave and convex surfaces. Identify a saddle joint of the skeleton. A. Interphalangeal joint of the finger B. Carpometacarpal joint of the phalanges C. Carpometacarpal joint of the thumb D. Metacarpophalangeal joint of the finger

Select the most correct statement concerning skin cancer. A. Most tumors that arise on the skin are malignant. B. Squamous cell carcinomas arise from the stratum corneum. C. Melanomas are rare but must be removed quickly to prevent them from metastasizing. D. Basal cell carcinomas are the least common but most malignant.

Synarthrotic joints ________. A. Have large joint cavities B. Characterize all cartilaginous joints C. Are immovable joints D. Are found only in adults

Synovial fluid is present in joint cavities of freely movable joints. Which of the following statements is true about this fluid? A. It contains hydrochloric acid. B. It contains enzymes only. C. It contains hyaluronic acid. D. It contains lactic acid.

Tendon sheaths ________. A. Are extensions of periosteum B. Help anchor the tendon to the muscle C. Act as friction-reducing structures D. Are lined with dense irregular connective tissue

The gliding motion of the wrist uses ________ joints. A. Pivot B. Hinge C. Plane D. Condyloid

The reason that intervertebral discs exhibit a large amount of tensile strength, which allows them to absorb shock, is because they possess ________. A. Hydroxyapatite crystals B. Elastic fibers C. Collagen fibers D. Reticular fibers

The reason the hypodermis acts as a shock absorber is that ________. A. The cells that make up the hypodermis secrete a protective mucus B. It is located just below the epidermis and protects the dermis from shock C. The major part of its makeup is adipose, which serves as an effective shock absorber D. It has no delicate nerve endings and can therefore absorb more shock

The shape of the external ear is maintained by ________. A. Adipose tissue B. Hyaline cartilage C. Elastic cartilage D. Fibrocartilage

The single most abundant chemical substance of the body, accounting for 60% to 80% of body weight, is ________. A. Protein B. Hydrogen C. Water D. Oxygen

The strongest muscle contractions are normally achieved by ________. A. Recruiting small and medium muscle fibers B. Increasing stimulus above the threshold C. Increasing the stimulation up to the maximal stimulus D. Increasing stimulus above the treppe stimulus

The term diploë refers to the ________. A. Fact that most bones are formed of two types of bone tissue B. Double-layered nature of the connective tissue covering the bone C. Internal layer of spongy bone in flat bones D. Two types of marrow found within most bones

The type of joint between the carpal (trapezium) and the first metacarpal is a ________ joint. A. Condylar B. Plane C. Saddle D. Hinge

What is moving a limb away from the midline of the body along the frontal plane called? A. Flexion B. Extension C. Abduction D. Adduction

What is the primary function of wave summation? A. Prevent muscle fatigue B. Increase muscle tension C. Produce smooth, continuous muscle contraction D. Prevent muscle relaxation

What is the role of tropomyosin in skeletal muscles? A. Tropomyosin is the chemical that activates the myosin heads. B. Tropomyosin serves as a contraction inhibitor by blocking the actin binding sites on the myosin molecules. C. Tropomyosin serves as a contraction inhibitor by blocking the myosin binding sites on the actin molecules. D. Tropomyosin is the receptor for the motor neuron neurotransmitter.

What is the structural unit of compact bone? A. Spongy bone B. Lamellar bone C. The osteon D. Osseous matrix

What structure in skeletal muscle cells functions in calcium storage? A. Intermediate filament network B. Myofibrillar network C. Sarcoplasmic reticulum D. Mitochondria

Which muscle cells have the greatest ability to regenerate? A. Cardiac B. Skeletal C. Smooth D. No muscle can regenerate

Which of the following are cartilaginous joints? A. Sutures B. Gomphoses C. Synchondroses D. Syndesmoses

Which of the following is a factor that affects the velocity and duration of muscle contraction? A. Size of the muscle fibers stimulated B. Number of muscle fibers stimulated C. Load on the fiber D. Muscle length

Which type of skin cancer appears as a scaly reddened papule and tends to grow rapidly and metastasize? A. Basal cell carcinoma B. Adenoma C. Squamous cell carcinoma D. Melanoma

ABCD Rule Contains several colors (black, brown, tan, sometimes red or blue)

C Color

- Areolar connective tissue • Most widely distributed CT • Supports and binds other tissues • Universal packing material between other tissues • Contains fibroblasts that secrete loose arrangement of mostly collagen fibers • Loose fibers allow for increased ground substance, which can act as water reservoir by holding more interstitial fluid • Macrophages and fat cells are contained in spaces . Reticular connective tissue • Resembles areolar tissue, but fibers are thinner reticular fibers • Fibroblast cells are called reticular cells - Secrete reticular fibers made up of thin collagen • Reticular fibers form a mesh-like stroma that acts as a support for blood cells in lymph nodes, spleen, and bone marrow - Adipose tissue • White fat - Similar to areolar tissue but greater nutrient storage - Cells are called adipocytes - Scanty matrix - Richly vascularized - Functions in shock absorption, insulation, and energy storage • Brown fat - Use lipid fuels to heat bloodstream rather than to produce ATP, as does white fat

CT proper Loose connective tissues

- Surrounding cartilage matrix calcifies; chondrocytes die and deteriorate

Calcification Zone

. Hairlike canals that connect lacunae to each other and to central canal

Canaliculi

-Central (Haversian) canal runs through core of osteon •Contains blood vessels and nerve fibers -Perforating (Volkmann's) ______: _______ lined with endosteum that occur at right angles to central ______ •Connect blood vessels and nerves of periosteum, medullary cavity, and central _______ -Lacunae: small cavities that contain osteocytes -_______: hairlike canals that connect lacunae to each other and to central canal -Osteoblasts that secrete bone matrix maintain contact with each other and osteocytes via cell projections with gap junctions -When matrix hardens and cells are trapped the ________ form •Allow communication between all osteocytes of osteon and permit nutrients and wastes to be relayed from one cell to another

Canals and Canaliculi

• Yellow to orange pigment • Most obvious in palms and soles • Accumulates in stratum corneum and hypodermis • Can be converted to vitamin A for vision and epidermal health

Carotene

- Matrix secreted from chondroblasts (during growth) and chondrocytes (adults) • Chondrocytes found in cavities called lacunae • 80% water, with packed collagen fibers and sugar proteins (chondroitin and hyaluronic acid) - Tough yet flexible material that lacks nerve fibers - Avascular: receives nutrients from membrane surrounding it (perichondrium) • Periochondrium gives rise to chondroblasts and chondrocytes

Cartilage

______ is made up of chondrocytes, cells encased in small cavities (lacunae) within jelly-like extracellular matrix •Three types of _______: -Hyaline ________ •Provides support, flexibility, and resilience •Most abundant type; contains collagen fibers only •Articular (joints), costal (ribs), respiratory (larynx), nasal ________ (nose tip) -Elastic ________ •Similar to hyaline _______, but contains elastic fibers •External ear and epiglottis -Fibro_______ •Thick collagen fibers: has great tensile strength •Menisci of knee; vertebral discs •_______ grows in two ways: -Appositional growth •_______-forming cells in perichondrium secrete matrix against external face of existing cartilage -New matrix laid down on surface of cartilage -Interstitial growth •Chondrocytes within lacunae divide and secrete new matrix, expanding _______ from within -New matrix made within _______ •Calcification of cartilage occurs during normal bone growth in youth, but can also occur in old age -Hardened cartilage_______ is not the same as bone

Cartilage

- Due to compression and shear stress - Fragments may cause joint to lock or bind - Cartilage rarely repairs itself - Repaired with arthroscopic surgery - Partial menisci removal renders joint less stable but mobile; complete removal leads to osteoarthritis - Meniscal transplant possible in younger patients - Perhaps meniscus grown from own stem cells in future

Cartilage Tears

What are some common joint injuries?

Cartilage tears Sprains Dislocations

• Bones united by _______ • Like fibrous joints, have no joint cavity • Not highly movable • Two types - Synchondroses - Symphyses . Synchondroses • Bar or plate of hyaline cartilage unites bones • Almost all are synarthrotic (immovable) • Examples - Temporary epiphyseal plate joints • Become synostoses after plate closure - Cartilage of 1st rib with manubrium of sternum • Fibrocartilage unites bone in symphysis joint - Hyaline cartilage also present as articular cartilage on bony surfaces • Symphyses are strong, amphiarthrotic (slightly movable) joints • Examples - Intervertebral joints - Pubic symphysis

Cartilaginous Joints

Smooth Muscle Microscopic Structure . Sarcolemma contains pouch like inholdings . contain numerous Ca2+ channels that open to allow rapid influx of extracellular Ca2+

Caveolae

•Body contains internal _____ that are closed to environment •______ provide different degrees of protection to organs within them

Cavities

Single cell

Cellular Level

Canaliculi . Runs through core of osteon •Contains blood vessels and nerve fibers

Central Canal

Whole Muscle Contraction Graded Muscle Response - Single stimulus results in single contractile response (i.e., muscle twitch) - Wave (temporal) summation results if two stimuli are received by a muscle in rapid succession • Muscle fibers do not have time to completely relax between stimuli, so twitches increase in force with each stimulus • Additional Ca2+ that is released with second stimulus stimulates more shortening • Produces smooth, continuous contractions that add up (summation) • Further increase in stimulus frequency causes muscle to progress to sustained, quivering contraction referred to as unfused (incomplete) tetanus - If stimuli frequency increases, muscle tension reaches maximum • Referred to as fused (complete) tetanus because contractions "fuse" into one smooth sustained contraction plateau • Prolonged muscle contractions lead to muscle fatigue - Recruitment (or multiple motor unit summation): stimulus is sent to more muscle fibers, leading to more precise control - Types of stimulus involved in recruitment: • Subthreshold stimulus: stimulus not strong enough, so no contractions seen • Threshold stimulus: stimulus is strong enough to cause first observable contraction • Maximal stimulus: strongest stimulus that increases maximum contractile force - All motor units have been recruited - Recruitment works on size principle • Motor units with smallest muscle fibers are recruited first • Motor units with larger and larger fibers are recruited as stimulus intensity increases • Largest motor units are activated only for most powerful contractions • Motor units in muscle usually contract asynchronously - Some fibers contract while others rest - Helps prevent fatigue

Changing Frequency of Stimulation

What are the two ways muscle responses are graded?

Changing frequency of stimulation Changing strength of stimulation

Muscle Fiber Contraction • Nerve impulse travels down axon of motor neuron • When impulse reaches axon terminal, voltage-gated calcium channels open, and Ca2+ enters axon terminal • Ca2+ influx causes synaptic vesicle to exocytose Ach into synaptic cleft • ACh binds to receptors on sarcolemma, causing chemically gated Na+-K+ channels to open and initiate an end plate potential • When threshold is reached, voltage-gated Na+ channels open, initiating an AP

Channels Involved in Initiating Muscle Contraction

Bending your head back until it hurts is an example of ________. A. Flexion B. Extension C. Circumduction D. Hyperextension

- Skin secretes many chemicals, such as: • Sweat, which contains antimicrobial proteins • Sebum and defensins, which kill bacteria • Cells also secrete antimicrobial defensin - Acid mantle: low pH of skin retards bacterial multiplication - Melanin provides a chemical barrier against UV radiation damage

Chemical Barrier

•Bone is made up of both organic and inorganic components -Organic components •Includes osteogenic cells, osteoblasts, osteocytes, bone-lining cells, osteoclasts, and osteoid -Osteoid, which makes up one-third of organic bone matrix, is secreted by osteoblasts » Consists of ground substance and collagen fibers, which contribute to high tensile strength and flexibility of bone -Resilience of bone is due to sacrificial bonds in or between collagen molecules that stretch and break to dissipate energy and prevent fractures -If no additional trauma, bonds re-form •Inorganic components -Hydroxyapatites (mineral salts) •Makeup 65% of bone by mass •Consist mainly of tiny calcium phosphate crystals in and around collagen fibers •Responsible for hardness and resistance to compression -Bone is half as strong as steel in resisting compression and as strong as steel in resisting tension -Lasts long after death because of mineral composition -Can reveal information about ancient people

Chemical Composition of Bone

Atoms, molecules, and organelles

Chemical Level

What are three barriers that protect the skin?

Chemical Physical Biological

Blast Cells Found in cartilage

Chondroblasts

During Growth

Chondroblasts

Adults • Found in cavities called lacunae • 80% water, with packed collagen fibers and sugar proteins (chondroitin and hyaluronic acid)

Chondrocytes

Smooth Muscle Microscopic Structure . Fibers run around circumference of organ • Contraction causes lumen of organ to constrict

Circular Layer

Angular Movements • Involves flexion, abduction, extension, and adduction of limb • Limb describes cone in space

Circumduction

Connective Tissue Proper Dense Connective Tissue

Dense regular Dense irregular Elastic

•Just deep to periosteum, but superficial to endosteum, these layers of lamellae extend around entire surface of diaphysis •Help long bone to resist twisting

Circumferential Lamellae

. In reticular layer are caused by many collagen fibers running parallel to skin surface - Externally invisible - Important to surgeons because incisions parallel to ______ lines heal more readily

Cleavage

Fracture . Simple . Skin is not penetrated

Closed

Fracture Physician manipulates to correct position

Closed Reduction

Muscle Fiber Contraction Cross Bridge Cycling . Energy from hydrolysis of ATP "cocks" myosin head into high-energy state • This energy will be used for power stroke in next cross bridge cycle

Cocking of Myosin Head

Connective Tissue Fibers • Strongest and most abundant type • Tough; provides high tensile strength

Collagen

What are the three types of fibers that provide support for connective tissue?

Collagen Elastic fibers Reticular

Epithelia Tall, column-like

Columnar

-Also called lamellar bone -Consists of: •Osteon (Haversian system) •Canals and canaliculi •Interstitial and circumferential lamella

Compact Bone

- Consists of all connective tissues except bone, cartilage, and blood - Two subclasses • CT proper: loose connective tissues - Areolar - Adipose - Reticular • CT proper: dense connective tissues - Dense regular - Dense irregular - Elastic

Connective Tissue Proper

-Also called lamellar bone -Consists of: •Osteon (Haversian system) •Canals and canaliculi •Interstitial and circumferential lamella •Osteon (Haversian system) -An osteon is the structural unit of compact bone -Consists of an elongated cylinder that runs parallel to long axis of bone •Acts as tiny weight-bearing pillars -An osteon cylinder consists of several rings of bone matrix called lamellae •Lamellae contain collagen fibers that run in different directions in adjacent rings •Withstands stress and resist twisting •Bone salts are found between collagen fibers •Canals and canaliculi -Central (Haversian) canal runs through core of osteon •Contains blood vessels and nerve fibers -Perforating (Volkmann's) canals: canals lined with endosteum that occur at right angles to central canal •Connect blood vessels and nerves of periosteum, medullary cavity, and central canal -Lacunae: small cavities that contain osteocytes -Canaliculi: hairlike canals that connect lacunae to each other and to central canal -Osteoblasts that secrete bone matrix maintain contact with each other and osteocytes via cell projections with gap junctions -When matrix hardens and cells are trapped the canaliculi form •Allow communication between all osteocytes of osteon and permit nutrients and wastes to be relayed from one cell to another •Interstitial and circumferential lamellae -Interstitial lamellae •Lamellae that are not part of osteon •Some fill gaps between forming osteons; others are remnants of osteons cut by bone remodeling -Circumferential lamellae •Just deep to periosteum, but superficial to endosteum, these layers of lamellae extend around entire surface of diaphysis •Help long bone to resist twisting

Compact Bone

Dense outer layer on every bone that appears smooth and solid

Compact Bone

-______ _______: dense outer layer on every bone that appears smooth and solid -_______ ______: made up of a honeycomb of small, needle-like or flat pieces of bone called trabeculae •Open spaces between trabeculae are filled with red or yellow bone marrow

Compact Spongey Bone

Fracture Broken all the way through

Complete

What are the two parts of the completeness of break in a fracture?

Complete Incomplete

Whole Muscle Contractions Isotonic and Isometric Contractions . Muscle shortens and does work - Example: biceps contract to pick up a book

Concentric Contractions

What are the two ways isotonic contractions can perform?

Concentric Eccentric

Supports, protects, binds other tissues together Bones Tendons Fats and other soft padding tissue

Connective Tissue

• The most abundant and widely distributed of primary tissues • Major functions: binding and support, protecting, insulating, storing reserve fuel, and transporting substances (blood) • Four main classes - ______ _____ proper - Cartilage - Bone - Blood • Three characteristics make _____ _______ different from other primary tissues: - All have common embryonic origin: all arise from mesenchyme tissue as their tissue of origin - Have varying degrees of vascularity (cartilage is avascular, bone is highly vascularized) - Cells are suspended/embedded in extracellular matrix (ECM) (protein-sugar mesh) • Matrix supports cells so they can bear weight, withstand tension, endure abuse • All ______ ______ have three main elements - Ground substance - Fibers - Cells • The first two elements (ground substance and fibers) together make up the extracellular matrix - Composition and arrangement of these three elements vary considerably in different types of ______ ______ • Ground substance - Unstructured gel-like material that fills space between cells • Medium through which solutes diffuse between blood capillaries and cells - Components • Interstitial fluid • Cell adhesion proteins ("glue" for attachment) • Proteoglycans (sugar proteins), made up of protein core + large polysaccharides - Example: chrondroitin sulfate and hyaluronic acid • Water also is trapped in varying amounts, affecting viscosity of ground substance • _____ ______ fibers • Three types of fibers provide support - Collagen • Strongest and most abundant type • Tough; provides high tensile strength - Elastic fibers • Networks of long, thin, elastin fibers that allow for stretch and recoil - Reticular • Short, fine, highly branched collagenous fibers (different chemistry and form from collagen fibers) • Branching forms networks that offer more "give" • Cells - "Blast" cells • Immature form of cell that actively secretes ground substance and ECM fibers • Fibroblasts found in connective tissue proper • Chondroblasts found in cartilage • Osteoblasts found in bone • Hematopoietic stem cells in bone marrow - "Cyte" cells • Mature, less active form of "blast" cell that now becomes part of and helps maintain health of matrix • Other cell types in ______ ______ - Fat cells • Store nutrients - White blood cells • Neutrophils, eosinophils, lymphocytes • Tissue response to injury - Mast cells • Initiate local inflammatory response against foreign microorganisms they detect - Macrophages • Phagocytic cells that "eat" dead cells, microorganisms; function in immune system • ______ _______ proper - Consists of all connective tissues except bone, cartilage, and blood - Two subclasses • CT proper: loose connective tissues - Areolar - Adipose - Reticular • CT proper: dense connective tissues - Dense regular - Dense irregular - Elastic • CT proper: loose connective tissues - Areolar connective tissue • Most widely distributed CT • Supports and binds other tissues • Universal packing material between other tissues • Contains fibroblasts that secrete loose arrangement of mostly collagen fibers • Loose fibers allow for increased ground substance, which can act as water reservoir by holding more interstitial fluid • Macrophages and fat cells are contained in spaces - Adipose tissue • White fat - Similar to areolar tissue but greater nutrient storage - Cells are called adipocytes - Scanty matrix - Richly vascularized - Functions in shock absorption, insulation, and energy storage • Brown fat - Use lipid fuels to heat bloodstream rather than to produce ATP, as does white fat . Reticular connective tissue • Resembles areolar tissue, but fibers are thinner reticular fibers • Fibroblast cells are called reticular cells - Secrete reticular fibers made up of thin collagen • Reticular fibers form a mesh-like stroma that acts as a support for blood cells in lymph nodes, spleen, and bone marrow • CT proper: dense connective tissues - Dense regular connective tissue • Very high tensile strength; can withstand high tension and stretching • Closely packed bundles of thick collagen fibers run parallel to direction of pull - Fibers appear as white structures » Great resistance to pulling - Fibers slightly wavy, so stretch a little • Fibroblasts manufacture collagen fibers and ground substance • Very few cells and ground substance, mostly fibers • Poorly vascularized • Example: tendons and ligaments - Dense irregular connective tissue • Same elements as dense regular, but bundles of collagen are thicker and irregularly arranged • Forms sheets rather than bundles • Resists tension from many directions • Found in: - Dermis - Fibrous joint capsules - Fibrous coverings of some organs . Elastic connective tissue • Some ligaments are very elastic - Example: ligaments connecting adjacent vertebrae must be very elastic • Also found in walls of many large arteries - Arteries need to stretch when blood enters and recoil to push blood out • Cartilage - Matrix secreted from chondroblasts (during growth) and chondrocytes (adults) • Chondrocytes found in cavities called lacunae • 80% water, with packed collagen fibers and sugar proteins (chondroitin and hyaluronic acid) - Tough yet flexible material that lacks nerve fibers - Avascular: receives nutrients from membrane surrounding it (perichondrium) • Periochondrium gives rise to chondroblasts and chondrocytes • Three types of cartilage: - Hyaline cartilage • Most abundant; "gristle" • Appears as shiny bluish glass • Found at tips of long bones, nose, trachea, larynx, and cartilage of the ribs - Elastic cartilage • Similar to hyaline but with more elastic fibers • Found in ears and epiglottis - Fibrocartilage • Properties between hyaline and dense regular tissue • Strong, so found in areas such as intervertebral discs and knee • Bone - Also called osseous tissue - Supports and protects body structures - Stores fat and synthesizes blood cells in cavities - Has more collagen compared to cartilage - Has inorganic calcium salts - Osteoblasts produce matrix - Osteocytes maintain the matrix • Reside in cavities in matrix called lacunae - Osteons: individual structural units - Richly vascularized

Connective Tissue

Muscle Tissue • Each skeletal muscle, as well as each muscle fiber, is covered in _______ ________ • Support cells and reinforce whole muscle • Sheaths from external to internal: - Epimysium: dense irregular connective tissue surrounding entire muscle; may blend with fascia - Perimysium: fibrous connective tissue surrounding fascicles (groups of muscle fibers) - Endomysium: fine areolar connective tissue surrounding each muscle fiber

Connective Tissue Sheaths

What are the four main classes of connective tissue?

Connective tissue proper Cartilage Bone Blood

Muscle Tissue . Ability to shorten forcibly when stimulated

Contractility

Skeletal Muscle Fibers Sliding Filament Model of Contraction . The activation of cross bridges to generate force

Contraction

Smooth Muscle • Mechanism of contraction - Slow, synchronized contractions - Cells electrically coupled by gap junctions • Action potentials transmitted from fiber to fiber - Some cells are self-excitatory (depolarize without external stimuli) • Act as pacemakers for sheets of muscle • Rate and intensity of contraction may be modified by neural and chemical stimuli - Contraction in smooth muscle is similar to skeletal muscle contraction in following ways: • Actin and myosin interact by sliding filament mechanism • Final trigger is increased intracellular Ca2+ level • ATP energizes sliding process • Contraction stops when Ca2+ is no longer available - Contraction in smooth muscle is different from skeletal muscle in following ways: • Some Ca2+ still obtained from SR, but mostly comes from extracellular space • Ca2+ binds to calmodulin, not troponin • Activated calmodulin then activates myosin kinase (myosin light chain kinase) • Activated myosin kinase phosphorylates myosin head, activating it - Leads to crossbridge formation with actin - Stopping smooth muscle contraction requires more steps than skeletal muscle • Relaxation requires: - Ca2+ detachment from calmodulin - Active transport of Ca2+ into SR and extracellularly - Dephosphorylation of myosin to inactive myosin • Energy efficiency of smooth muscle contraction - Slower to contract and relax but maintains contraction for prolonged periods with little energy cost • Slower ATPases • Myofilaments may latch together to save energy - Most smooth muscle maintain moderate degree of contraction constantly without fatiguing • Referred to as smooth muscle tone - Makes ATP via aerobic respiration pathways • Regulation of contraction - Controlled by nerves, hormones, or local chemical changes - Neural regulation • Neurotransmitter binding causes either graded (local) potential or action potential - Results in increases in Ca2+ concentration in sarcoplasm - Response depends on neurotransmitter released and type of receptor molecules » One neurotransmitter can have a stimulatory effect on smooth muscle in one organ, but an inhibitory effect in a different organ - Hormones and local chemicals • Some smooth muscle cells have no nerve supply - Depolarize spontaneously or in response to chemical stimuli that bind to G protein-linked receptors - Chemical factors can include hormones, high CO2, pH, low oxygen • Some smooth muscles respond to both neural and chemical stimuli • Special features of smooth muscle contraction - Response to stretch • Stress-relaxation response: responds to stretch only briefly, then adapts to new length - Retains ability to contract on demand - Enables organs such as stomach and bladder to temporarily store contents - Length and tension changes • Can contract when between half and twice its resting length - Allows organ to have huge volume changes without becoming flabby when relaxed

Contraction of Smooth Muscle

- Determines set point at which variable is maintained - Receives input from receptor - Determines appropriate response

Control Center

• ________ occurs continuously but is regulated by genetic factors and two control loops 1. Hormonal controls • Negative feedback loop that controls blood Ca2+ levels • Calcium functions in many processes, such as nerve transmission, muscle contraction, blood coagulation, gland and nerve secretions, as well as cell division • 99% of 1200-1400 gms of calcium are found in bone • Intestinal absorption of Ca2+ requires vitamin D 2. Response to mechanical stress 1. Hormonal controls - Parathyroid hormone (PTH): produced by parathyroid glands in response to low blood calcium levels • Stimulates osteoclasts to resorb bone • Calcium is released into blood, raising levels • PTH secretion stops when homeostatic calcium levels are reached - Calcitonin: produced by parafollicular cells of thyroid gland in response to high levels of blood calcium levels • Effects are negligible, but at high pharmacological doses it can lower blood calcium levels temporarily- Other hormones play a role in bone density and turnover • Leptin - Hormone released by adipose tissue - May play role in bone density regulation by inhibiting osteoblasts • Serotonin - Neurotransmitter regulates mood and sleep; also interferes with osteoblast activity - Most serotonin made in gut - Secreted into blood after a meal - May inhibit bone turnover after a meal, so bone calcium is locked in when new calcium is flooding into bloodstream 2. Response to mechanical stress - Bones reflect stresses they encounter • Bones are stressed when weight bears on them or muscles pull on them - Wolf's law states that bones grow or remodel in response to demands placed on them • Stress is usually off center, so bones tend to bend • Bending compresses one side, stretches other side - Diaphysis is thickest where bending stresses are greatest - Bone can be hollow because compression and tension cancel each other out in center of bone - Wolf's law also explains: • Handedness (right- or left-handed) results in thicker and stronger bone of the corresponding upper limb • Curved bones are thickest where most likely to buckle • Trabeculae form trusses along lines of stress • Large, bony projections occur where heavy, active muscles attach - Weight lifters have enormous thickenings at muscle attachment sites of most used muscles • Bones of fetus and bedridden people are featureless because of lack of stress on bones • Mechanical stress causes remodeling by producing electrical signals when bone is deformed - Compressed and stretched regions are oppositely charged - Compression/tension changes fluid flows within canaliculi, which may also stimulate remodeling • Hormonal controls determine whether and when remodeling occurs in response to changing blood calcium levels, but mechanical stress determines where it occurs

Control of Remodeling

Shoulder Joint • Helps support weight of upper limb

Corcaohumeral Ligament

• Composed of at least two primary tissue types: an epithelium bound to underlying connective tissue proper layer • Three types - Cutaneous _______ - Mucous ______ - Serous ______ . Cutaneous ______ • Another name for skin • Keratinized stratified squamous epithelium (epidermis) attached to a thick layer of connective tissue (dermis) • Unlike other ______, skin is a dry membrane . Mucous ______ • Mucosa indicates location, not cell composition • Also called mucosae - Line body cavities that are open to the exterior (example: digestive, respiratory, urogenital tracts) • Moist _____ bathed by secretions (or urine) • Epithelial sheet lies over layer of loose connective tissue called lamina propria • May secrete mucus . Serous _____ • Also called serosae • Found in closed ventral body cavities • Constructed from simple squamous epithelium (called mesothelium) resting on thin areolar connective tissue • Parietal serosae line internal body cavity walls • Visceral serosae cover internal organs • Cavity between layers is filled with slippery serous fluid, so these are moist ______ • Special names given to show location: pleurae (lungs), pericardium (heart), peritoneum (abdomen)

Covering and Lining Membranes

On external and internal surfaces (example: skin)

Covering and lining epithelia

What are two forms of epithelial tissue?

Covering and lining epithelia Glandular epithelia

Connective tissue extracellular matrix is composed of ________. A. Cells and fibers B. Ground substance and cells C. All organic compounds D. Fibers and ground substance

Creatine phosphate functions in the muscle cell by ________. A. Forming a chemical compound with actin B. Inducing a conformational change in the myofilaments C. Forming a temporary chemical compound with myosin D. Storing energy that will be transferred to ADP to resynthesize ATP

Glands, such as the thyroid, that secrete their products directly into the blood rather than through ducts are classified as ________. A. Sebaceous B. Exocrine C. Ceruminous D. Endocrine

Growth of bones is controlled by a symphony of hormones. Which hormone is of greatest importance for bone growth during infancy and childhood? A. Parathyroid hormone B. Calcitonin C. Thyroid hormones D. Growth hormone

If you consider your home air conditioner in terms of homeostasis, then the wall thermostat would be the ________. A. Variable B. Receptor C. Effector D. Control center

In an isotonic contraction, the muscle ________. A. Never converts pyruvate to lactate B. Does not change in length but increases tension C. Rapidly resynthesizes creatine phosphate and ATP D. Changes in length and moves the "load"

In the classification of joints, which of the following is true? A. In cartilaginous joints, a joint cavity is present. B. Immovable joints are called amphiarthroses. C. Synarthrotic joints are slightly movable. D. All synovial joints are freely movable.

Moving your jaw forward, causing an underbite, is called ________. A. Adduction B. Pronation C. Retraction D. Protraction

Muscle tone is ________. A. The ability of a muscle to efficiently cause skeletal movements B. The feeling of well-being following exercise C. The condition of athletes after intensive training D. A state of sustained partial contraction

Select the most correct statement concerning skin cancer. A. Basal cell carcinomas are the least common but most malignant. B. Squamous cell carcinomas arise from the stratum corneum. C. Most tumors that arise on the skin are malignant. D. Melanomas are rare but must be removed quickly to prevent them from metastasizing.

Sudoriferous (sweat) glands are categorized as two distinct types. Which of the following are the two types of sweat glands? A. Mammary and ceruminous B. Holocrine and mammary C. Sebaceous and merocrine D. Eccrine and apocrine

The heart lies in the ________ cavity. A. Superior mediastinal B. Dorsal C. Pleural D. Pericardial

The hip joint is a good example of a(n) ________ synovial joint. A. Uniaxial B. Biaxial C. Nonaxial D. Multiaxial

The process of bones increasing in thickness is known as ________. A. Epiphyseal plate closure B. Concentric growth C. Closing of the epiphyseal plate D. Appositional growth

The reason that intervertebral discs exhibit a large amount of tensile strength, which allows them to absorb shock, is because they possess ________. A. Reticular fibers B. Hydroxyapatite crystals C. Elastic fibers D. Collagen fibers

The strongest muscle contractions are normally achieved by ________. A. Increasing stimulus above the treppe stimulus B. Recruiting small and medium muscle fibers C. Increasing stimulus above the threshold D. Increasing the stimulation up to the maximal stimulus

What is the functional role of the T tubules? A. Hold cross bridges in place in a resting muscle B. Synthesize ATP to provide energy for muscle contraction C. Stabilize the G and F actin D. Enhance cellular communication during muscle contraction

What is the functional unit of a skeletal muscle called? A. The sarcoplasmic reticulum B. A myofibril C. A myofilament D. A sarcomere

What is the primary function of wave summation? A. Prevent muscle relaxation B. Prevent muscle fatigue C. Increase muscle tension D. Produce smooth, continuous muscle contraction

Which glands produce ear wax? A. Apocrine glands B. Merocrine glands C. Eccrine Glands D. Ceruminous glands

Which of the following is not a part of the synovial joint? A. Articular capsule B. Joint cavity C. Articular cartilage D. Tendon sheath

Which of the following is the correct sequence of events for muscle contractions? A. Neurotransmitter release, muscle cell action potential, motor neuron action potential, release of calcium ions from SR, sliding of myofilaments, ATP-driven power stroke B. Muscle cell action potential, neurotransmitter release, ATP-driven power stroke, calcium ion release from SR, sliding of myofilaments C. Neurotransmitter release, motor neuron action potential, muscle cell action potential, release of calcium ions from SR, ATP-driven power stroke D. otor neuron action potential, neurotransmitter release, muscle cell action potential, release of calcium ions from SR, ATP-driven power stroke, sliding of myofilaments

________ cavities are spaces within joints. A. Orbital B. Nasal C. Oral D. Synovial

ABCD Rule Larger than 6 mm (size of pencil eraser)

D Diameter

What are the three dense connective tissues?

Dense regular Dense irregular Elastic

What are some of the treatments for burns?

Debridement of burned skin Antibiotics Temporary covering Skin grafts

Away from the body surface

Deep

Factors of Muscle Contraction . Muscle fibers with sarcomeres that are 80-120% their normal resting length generate more force • If sarcomere is less than 80% resting length, filaments overlap too much, and force decreases • If sarcomere is greater than 120% of resting length, filaments do not overlap enough so force decreases

Degree of Muscle Stretch

• Star-shaped macrophages that patrol deep epidermis - Are key activators of immune system

Dendritic

• Monoclonal antibody shown to reduce fractures in men with prostate cancer • Improves bone density in elderly

Denosumab

Smooth Muscle Microscopic Structure . Proteins that anchor filaments to sarcolemma at regular intervals - Correspond to Z discs of skeletal muscle

Dense Bodies

• Same elements as dense regular, but bundles of collagen are thicker and irregularly arranged • Forms sheets rather than bundles • Resists tension from many directions • Found in: - Dermis - Fibrous joint capsules - Fibrous coverings of some organs Description:Primarily irregularly arranged collagen fibers; some elastic fibers; fibroblast is the major cell type. Function:Withstands tension exerted in many directions; provides structural strength. Location:Fibrous capsules of organs and of joints; dermis of the skin; submucosa of digestive tract.

Dense Irregular Connective Tissue

• Very high tensile strength; can withstand high tension and stretching • Closely packed bundles of thick collagen fibers run parallel to direction of pull - Fibers appear as white structures » Great resistance to pulling - Fibers slightly wavy, so stretch a little • Fibroblasts manufacture collagen fibers and ground substance • Very few cells and ground substance, mostly fibers • Poorly vascularized • Example: tendons and ligaments Description:Primarily parallel collagen fibers; a few elastic fibers; major cell type is the fibroblast. Function:Attaches muscles to bones or to muscles; attaches bones to bones; withstands great tensile stress when pulling force is applied in one direction. Location:Tendons, most ligaments, aponeuroses.

Dense Regular Connective Tissue

. Bowl- or groove-like cut-out that can serve as passageways for vessels and nerves, or plays a role in joints

Depression

. Superficial region of dermis that sends fingerlike projections up into epidermis - Projections contains capillary loops, free nerve endings, and touch receptors (tactile corpuscles, also called Meissner's corpuscles)

Dermal Papillae

. Underlies epidermis • Mostly fibrous connective tissue, vascular

Dermis

• Strong, flexible connective tissue • Cells include fibroblasts, macrophages, and occasionally mast cells and white blood cells • Fibers in matrix bind body together - Makes up the "hide" that is used to make leather • Contains nerves, blood vessels, and lymphatic vessels • Contains epidermal hair follicles, oil glands, and sweat glands • Two layers - Papillary - Reticular . Papillary Layer • Superficial layer of areolar connective tissue consisting of loose, interlacing collagen and elastic fibers and blood vessels • Loose fibers allow phagocytes to patrol for microorganisms • _____ papillae: superficial region of _____ that sends fingerlike projections up into epidermis - Projections contains capillary loops, free nerve endings, and touch receptors (tactile corpuscles, also called Meissner's corpuscles) • In thick skin, _____ papillae lie on top of ______ ridges, which give rise to epidermal ridges - Collectively ridges are called friction ridges • Enhance gripping ability • Contribute to sense of touch • Sweat pores in ridges leave unique fingerprint pattern . Reticular Layer • Makes up ~80% of ______ thickness • Consists of coarse, dense fibrous connective tissue - Many elastic fibers provide stretch-recoil properties - Collagen fibers provide strength and resiliency • Bind water, keeping skin hydrated • Extracellular matrix contains pockets of adipose cells • Cleavage (tension) lines in reticular layer are caused by many collagen fibers running parallel to skin surface - Externally invisible - Important to surgeons because incisions parallel to cleavage lines heal more readily • Flexure lines of reticular layer are ______ folds at or near joints - ______ is tightly secured to deeper structures - Skin's inability to slide easily for joint movement causes deep creases - Visible on hands, wrists, fingers, soles, toes

Dermis

Studies anatomical and physiological development throughout life • Embryology: study of developments before birth

Developmental Anatomy

. Tubular shaft that forms long axis of bone -Consists of compact bone surrounding central medullary cavity that is filled with yellow marrow in adults

Diaphysis

Freely movable joints

Diarthroses

• Capsular: thickened part of fibrous layer • Extracapsular: outside the capsule • Intracapsular: deep to capsule; covered by synovial membrane

Different types of reinforcing ligaments

Breakdown of ingested foodstuffs, followed by absorption of simple molecules into blood

Digestion

Breaks down food into absorbable units that enter the blood for distribution to body cells. Indigestible foodstuffs are eliminated as feces.

Digestive System

On internal surfaces, lining cells

Endosteal Cells

Energy for Contraction and ATP - Creatine phosphate is a unique molecule located in muscle fibers that donates a phosphate to ADP to instantly form ATP • Creatine kinase is enzyme that carries out transfer of phosphate • Muscle fibers have enough ATP and CP reserves to power cell for about 15 seconds Creatine phosphate + ADP creatine + ATP

Direct Phosphorylation of ADP by Creatine Phosphate

What are the three ways ATP can be regenerated quickly?

Direct phosphorylation of ADP by creatine phosphate Anaerobic pathway glycolysis and lactic acid formation Aerobic respiration

Describe one body structure in relation to another body structure -Direction is always based on standard anatomical position -Right and left refer to the body being viewed, not right and left of observer

Directional Terms

• Alterations in skin color can indicate ____ - Cyanosis • Blue skin color: low oxygenation of hemoglobin - Erythema (redness) • Fever, hypertension, inflammation, allergy - Pallor (blanching or pale color) • Anemia, low blood pressure, fear, anger - Jaundice (yellow cast) • Liver disorders - Bronzing • Inadequate steroid hormones (example: Addison's disease) - Bruises (black-and-blue marks) • Clotted blood beneath skin

Disease

- Bones forced out of alignment - Accompanied by sprains, inflammation, and difficulty moving joint - Caused by serious falls or contact sports - Must be reduced to treat • Subluxation: partial dislocation of a joint

Dislocations

Luxations

Dislocations

Common Joint Injuries • Cartilage tears - Due to compression and shear stress - Fragments may cause joint to lock or bind - Cartilage rarely repairs itself - Repaired with arthroscopic surgery - Partial menisci removal renders joint less stable but mobile; complete removal leads to osteoarthritis - Meniscal transplant possible in younger patients - Perhaps meniscus grown from own stem cells in future • Sprains - Reinforcing ligaments are stretched or torn - Common sites are ankle, knee, and lumbar region of back - Partial tears repair very slowly because of poor vascularization - Three options if torn completely • Ends of ligaments can be sewn together • Replaced with grafts • Just allow time and immobilization for healing • Dislocations (luxations) - Bones forced out of alignment - Accompanied by sprains, inflammation, and difficulty moving joint - Caused by serious falls or contact sports - Must be reduced to treat • Subluxation: partial dislocation of a joint . Inflammatory and Degenerative Conditions • Bursitis - Inflammation of bursa, usually caused by blow or friction - Treated with rest and ice and, if severe, anti-inflammatory drugs • Tendonitis - Inflammation of tendon sheaths, typically caused by overuse - Symptoms and treatment similar to those of bursitis • Arthritis - >100 different types of inflammatory or degenerative diseases that damage joints - Most widespread crippling disease in the U.S. - Symptoms: pain, stiffness, and swelling of joint - Acute forms: caused by bacteria, treated with antibiotics - Chronic forms: osteoarthritis, rheumatoid arthritis, and gouty arthritis • Osteoarthritis (OA) - Most common type of arthritis - Irreversible, degenerative ("wear-and-tear") arthritis - May reflect excessive release of enzymes that break down articular cartilage • Cartilage is broken down faster than it is replaced • Bone spurs (osteophytes) may form from thickened ends of bones - By age 85, half of Americans develop OA, more women than men - OA is usually part of normal aging process - Joints may be stiff and make crunching noise referred to as crepitus, especially upon rising - Treatment: moderate activity, mild pain relievers, capsaicin creams • Glucosamine, chondroitin sulfate, and nutritional supplements not effective • Rheumatoid arthritis (RA) - Chronic, inflammatory, autoimmune disease of unknown cause • Immune system attacks own cells - Usually arises between ages 40 and 50, but may occur at any age; affects three times as many women as men - Signs and symptoms include joint pain and swelling (usually bilateral), anemia, osteoporosis, muscle weakness, and cardiovascular problems - RA begins with inflammation of synovial membrane (synovitis) of affected joint - Inflammatory blood cells migrate to joint, release inflammatory chemicals that destroy tissues - Synovial fluid accumulates, causing joint swelling - Inflamed synovial membrane thickens into abnormal pannus tissue that clings to articular cartilage - Pannus erodes cartilage, scar tissue forms and connects articulating bone ends (ankylosis) - Treatment includes steroidal and nonsteroidal anti-inflammatory drugs to decrease pain and inflammation - Disruption of destruction of joints by immune system • Immune suppressants slow autoimmune reaction • Some agents target tumor necrosis factor to block action of inflammatory chemicals - Can replace joint with prosthesis • Gouty arthritis - Deposition of uric acid crystals in joints and soft tissues, followed by inflammation - More common in men - Typically affects joint at base of great toe - In untreated gouty arthritis, bone ends fuse and immobilize joint - Treatment: drugs, plenty of water, avoidance of alcohol and foods high in purines, such as liver, kidneys, and sardines • Lyme disease - Caused by bacteria transmitted by tick bites - Symptoms: skin rash, flu-like symptoms, and foggy thinking - May lead to joint pain and arthritis - Treatment • Long course of antibiotics

Disorders of Joints

Fracture Ends are out of normal alignment

Displaced

Farther from the origin of a body part or attachment of a limb to the body trunk

Distal

Protects fragile nervous system •Two subdivisions -Cranial cavity •Encases brain -Vertebral cavity •Encases spinal cord

Dorsal Body Cavity

What are the two body cavities?

Dorsal Ventral

• ________: bending foot toward shin • _____ ______: pointing toes

Dorsiflexion Plantar flexion

Cerumen

Earwax

Whole Muscle Contractions Isotonic and Isometric Contractions . Muscle lengthens and generates force - Example: laying a book down causes biceps to lengthen while generating a force

Eccentric Contractions

Merocrine

Eccrine

What are the two types of sweat glands?

Eccrine Apocrine

• Most numerous type • Abundant on palms, soles, and forehead • Ducts connect to pores • Function in thermoregulation - Regulated by sympathetic nervous system • Their secretion is sweat - 99% water, salts, vitamin C, antibodies, dermcidin (microbe-killing peptide), metabolic wastes

Eccrine Sweat Glands

• Primary germ layers - Superficial to deep: ectoderm, mesoderm, and endoderm - Formed early in embryonic development - Specialize to form the four primary tissues • Nerve tissue arises from _____ • Muscle and connective tissues arise from _____ • ______ tissues arise from all three germ layers • Tissues function well through youth and middle age if given adequate ____ and ______ and if wounds and infections are minimal • As the body ages, ______ thin, so they are more easily breached • Tissue repair is less efficient • Bone, muscle tissues, and nervous tissues begin to _____ • DNA mutations increase _____ risk

Ectoderm Mesoderm Epithelial Diet Circulation Epithelia Atrophy Cancer

- Receives output from control center - Provides the means to respond - Response either reduces stimulus (negative feedback) or enhances stimulus (positive feedback)

Effector

Cartilage • Similar to hyaline but with more elastic fibers • Found in ears and epiglottis Description:Similar to hyaline cartilage, but more elastic fibers in matrix. Function:Maintains the shape of a structure while allowing great flexibility. Location:Supports the external ear (pinna); epiglottis

Elastic

•Similar to hyaline cartilage, but contains elastic fibers •External ear and epiglottis

Elastic Cartilage

Covers inside portion of compact bone

Endosteum

• Some ligaments are very elastic - Example: ligaments connecting adjacent vertebrae must be very elastic • Also found in walls of many large arteries - Arteries need to stretch when blood enters and recoil to push blood out Description:Dense regular connective tissue containing a high proportion of elastic fibers. Function:Allows tissue to recoil after stretching; maintains pulsatile flow of blood through arteries; aids passive recoil of lungs following inspiration. Location:Walls of large arteries; within certain ligaments associated with the vertebral column; within the walls of the bronchial tubes.

Elastic Connective Tissue

Connective Tissue Fibers • Networks of long, thin, elastin fibers that allow for stretch and recoil

Elastic Fibers

Muscle Tissue . Ability to recoil to resting length

Elasticity

• Humerus articulates with radius and ulna • Hinge joint formed primarily from trochlear notch of ulna articulating with trochlea of humerus - Allows for flexion and extension only • Anular ligament surrounds head of radius • Two capsular ligaments restrict side-to-side movement - Ulnar collateral ligament - Radial collateral ligament

Elbow Joint

• ________: lifting body part superiorly - Example: shrugging shoulders • ________: lowering body part - Example: opening jaw

Elevation and Depression

Muscle Fiber Contraction Generation of an Action Potential Across the Sarcolemma - ACh released from motor neuron binds to ACh receptors on sarcolemma - Causes chemically gated ion channels (ligands) on sarcolemma to open - Na+ diffuses into muscle fiber • Some K+ diffuses outward, but not much - Because Na+ diffuses in, interior of sarcolemma becomes less negative (more positive) - Results in local depolarization called ______ _______ ______

End Plate Potential

What three steps occur when there is a generation of an action potential across the sarcolemma?

End plate potential Depolarization Repolarization

- Bone forms by replacing hyaline cartilage - Bones are called cartilage (_______) bones - Form most of skeleton - Forms essentially all bones inferior to base of skull, except clavicles - Begins late in month 2 of development - Uses previously formed hyaline cartilage models - Requires breakdown of hyaline cartilage prior to ossification - Begins at primary ossification center in center of shaft • Blood vessels infiltrate perichondrium, converting it to periosteum • Mesenchymal cells specialize into osteoblast

Endochondral Ossification

Glandular Epithelia What are the two sites called that products are released?

Endocrine Exocrine

Glandular Epithelia . Internally secreting (example: hormones) . Ductless glands 1. Secretions are not released into a duct; are released into surrounding interstitial fluid, which is picked up by circulatory system . Secrete (by exocytosis) hormones, messenger chemicals that travel through lymph or blood to their specific target organs . Target organs respond in some characteristic way

Endocrine Gland

Glands secrete hormones that regulate processes such as growth, reproduction, and nutrient use (metabolism) by body cells.

Endocrine System

Connective Tissue Sheath . Fine areolar connective tissue surrounding each muscle fiber

Endomysium

» Delicate connective tissue membrane covering internal bone surface » Covers trabeculae of spongy bone » Lines canals that pass through compact bone » Like periosteum, contains osteogenic cells that can differentiate into other bone cells

Endosteum

Simple Squamous Epithelia Lining of lymphatic vessels, blood vessels, and heart

Endothelium

What are two special simple squamous epithelia based on location?

Endothelium Mesothelium

What are three options to fix sprains if torn completely?

Ends of ligaments can be sewn together Replaced with grafts Just allow time and immobilization for healing

Energy for Contraction and ATP - Aerobic endurance • Length of time muscle contracts using aerobic pathways - Light-to-moderate activity, which can continue for hours - Anaerobic threshold • Point at which muscle metabolism converts to anaerobic pathway

Energy Systems Used During Sports

• ATP supplies the energy needed for the muscle fiber to: - Move and detach cross bridges - Pump calcium back into SR - Pump Na+ out of and K+ back into cell after excitation-contraction coupling • Available stores of ATP depleted in 4-6 seconds • ATP is the only source of energy for contractile activities; therefore it must be regenerated quickly • ATP is regenerated quickly by three mechanisms: - Direct phosphorylation of ADP by creatine phosphate (CP) - Anaerobic pathway: glycolysis and lactic acid formation - Aerobic respiration • Direct phosphorylation of ADP by creatine phosphate (CP) - Creatine phosphate is a unique molecule located in muscle fibers that donates a phosphate to ADP to instantly form ATP • Creatine kinase is enzyme that carries out transfer of phosphate • Muscle fibers have enough ATP and CP reserves to power cell for about 15 seconds Creatine phosphate + ADP creatine + AT P• Anaerobic pathway: glycolysis and lactic acid formation - ATP can also be generated by breaking down and using energy stored in glucose • Glycolysis: first step in glucose breakdown - Does not require oxygen - Glucose is broken into 2 pyruvic acid molecules - 2 ATPs are generated for each glucose broken down • Low oxygen levels prevent pyruvic acid from entering aerobic respiration phase - Normally, pyruvic acid enters mitochondria to start aerobic respiration phase; however, at high intensity activity, oxygen is not available • Bulging muscles compress blood vessels, impairing oxygen delivery - In the absence of oxygen, referred to as anaerobic glycolysis, pyruvic acid is converted to lactic acid - Lactic acid • Diffuses into bloodstream • Used as fuel by liver, kidneys, and heart • Converted back into pyruvic acid or glucose by liver - Anaerobic respiration yields only 5% as much ATP as aerobic respiration, but produces ATP 2½ times faster • Aerobic respiration - Produces 95% of ATP during rest and light-to-moderate exercise • Slower than anaerobic pathway - Consists of series of chemical reactions that occur in mitochondria and require oxygen • Breaks glucose into CO2, H2O, and large amount ATP (32 can be produced) - Fuels used include glucose from glycogen stored in muscle fiber, then bloodborne glucose, and free fatty acids • Fatty acids are main fuel after 30 minutes of exercise • Energy systems used during sports - Aerobic endurance • Length of time muscle contracts using aerobic pathways - Light-to-moderate activity, which can continue for hours - Anaerobic threshold • Point at which muscle metabolism converts to anaerobic pathway

Energy for Contraction and ATP

. Superficial region • Consists of epithelial tissue and is avascular

Epidermis

Skin surface

Epidermis

• _____ consists mostly of keratinized stratified squamous epithelium • Four cell types found in _______: 1. Keratinocytes • Produce fibrous keratin (protein that gives skin its protective properties) • Major cells of _______ • Tightly connected by desmosomes • Millions slough off every day 2. Melanocytes • Spider-shaped cells located in deepest ______ • Produce pigment melanin, which is packaged into melanosomes - Melanosomes are transferred to keratinocytes, where they protect nucleus from UV damage 3. Dendritic (Langerhans) cells • Star-shaped macrophages that patrol deep ______ - Are key activators of immune system 4. Tactile (Merkel) cells • Sensory receptors that sense touch • ______ is made up of four or five distinct layers - Thick skin contains five layers (strata) and is found in high-abrasion areas (hands, feet) - Thin skin contains only four strata • Five layers of skin 1. Stratum basale 2. Stratum spinosum 3. Stratum granulosum 4. Stratum lucidum (only in thick skin) 5. Stratum corneum 1. Stratum basale (basal layer) - Deepest of all _______ layers (base layer) - Layer that is firmly attached to dermis - Consists of a single row of stem cells that actively divide (mitotic), producing two daughter cells each time • One daughter cell journeys from basal layer to surface, taking 25-45 days to reach surface - Cell dies as it moves toward surface • Other daughter cell remains in stratum basale as stem cell - Layer also known as stratum germinativum because of active mitosis 2. Stratum spinosum (prickly layer) - Several cell layers thick - Cells contain weblike system of intermediate prekeratin filaments attached to desmosomes • Allows them to resist tension and pulling - Keratinocytes in this layer appear spikey, so they are called prickle cells - Scattered among keratinocytes are abundant melanosomes and dendritic cells 3. Stratum granulosum (granular layer) - Four to six cells thick, but cells are flattened, so layer is thin - Cell appearance changes • Cells flatten, nuclei and organelles disintegrate • Keratinization begins - Cells accumulate keratohyaline granules that help form keratin fibers in upper layers • Cells also accumulate lamellar granules, a water-resistant glycolipid that slows water loss - Cells above this layer die • Too far from dermal capillaries to survive 4. Stratum lucidum (clear layer) - Found only in thick skin - Consists of thin, translucent band of two to three rows of clear, flat, dead keratinocytes - Lies superficial to the stratum granulosum 5. Stratum corneum (horny layer) - 20-30 rows of flat, anucleated, keratinized dead cells - Accounts for three-quarters of ______ thickness - Though dead, cells still function to: • Protect deeper cells from the environment • Prevent water loss • Protect from abrasion and penetration • Act as a barrier against biological, chemical, and physical assaults • Cells change by going through apoptosis (controlled cell death) - Dead cells slough off as dandruff and dander - Humans can shed ~50,000 cells every minute

Epidermis

What are the three parts of the skin?

Epidermis Dermis Hypodermis

Connective Tissue Sheath . Dense irregular connective tissue surrounding entire muscle; may blend with fascia

Epimysium

What are the connective tissue sheaths from external to internal?

Epimysium Perimysium Endomysium

. Ends of long bones that consist of compact bone externally and spongy bone internally -Articular cartilage covers articular (joint) surfaces

Epiphysis

What do tissues have that regenerate extremely well?

Epithelial Bone Areolar connective Dense irregular connective Blood forming

What are the four basic tissue types?

Epithelial Connective Muscle Nervous

Hair Derived from epidermis

Epithelial Root Sheath

. Epithelium . Is a sheet of cells that covers body surfaces or cavities . Main functions: protection, absorption, filtration, excretion, secretion, and sensory reception . Has five distinguishing characteristics: 1. Polarity 2. Specialized contacts 3. Supported by connective tissues 4. Avascular, but innervated 5. Regeneration . Polarity 1. Cells have polarity (top and bottom) 2. Apical surface, upper free side, is exposed to surface or cavity - Most apical surfaces are smooth, but some have specialized fingerlike projections called microvilli 3. Basal surface, lower attached side, faces inwards toward body - Attaches to basal lamina, an adhesive sheet that holds basal surface of epithelial cells to underlying cells 4. Both surfaces differ in structure and function . Specialized contacts 1. _____ ______ need to fit closely together - Many form continuous sheets 2. Specialized contact points bind adjacent epithelial cells together - Lateral contacts include: a. Tight junctions b. Desmosomes . Connective tissue support 1. All epithelial sheets are supported by connective tissue 2. Reticular lamina - Deep to basal lamina - Consists of network of collagen fibers 3. Basement membrane - Made up of basal and reticular lamina - Reinforces epithelial sheet - Resists stretching and tearing - Defines epithelial boundary . Avascular, but innervated 1. No blood vessels are found in _____ ______ - Must be nourished by diffusion from underlying connective tissues 2. _____ are supplied by nerve fibers, however . Regeneration 1. _____ _____ have high regenerative capacities 2. Stimulated by loss of apical-basal polarity and broken lateral contacts 3. Some cells are exposed to friction, some to hostile substances, resulting in damage - Must be replaced - Requires adequate nutrients and cell division . All ______ ______ have two names 1. First name indicates number of cell layers - Simple ______ are a single layer thick - Stratified _______ are two or more layers thick and involved in protection (example: skin) 2. Second name indicates shape of cells - Squamous: flattened and scale-like - Cuboidal: box-like, cube - Columnar: tall, column-like 3. In stratified epithelia, shape can vary in each layer, so cell is named according to the shape in apical layer . Simple ______ 1. Involved in absorption, secretion, or filtration processes 2. Simple squamous ________ - Cells are flattened laterally, and cytoplasm is sparse - Function where rapid diffusion is priority a. Example: kidney, lungs - Two special simple squamous epithelia are based on locations a. Endothelium: lining of lymphatic vessels, blood vessels, and heart b. Mesothelium: serous membranes in the ventral body cavity . Simple cuboidal _______ 1. Single layer of cells 2. Involved in secretion and absorption 3. Forms walls of smallest ducts of glands and many kidney tubules . Simple columnar _______ 1. Single layer of tall, closely packed cells - Some cells have microvilli, and some have cilia - Some layers contain mucus-secreting goblet cells 2. Involved in absorption and secretion of mucus, enzymes, and other substances - Ciliated cells move mucus 3. Found in digestive tract, gallbladder, ducts of some glands, bronchi, and uterine tubes . Pseudostratified columnar ________ 1. Cells vary in height and appear to be multi-layered and stratified, but tissue is in fact single-layered simple _______ - "Pseudo" means false - Many cells are ciliated 2. Involved in secretion, particularly of mucus, and also in movement of mucus via ciliary sweeping action 3. Located mostly in upper respiratory tract, ducts of large glands, and tubules in testes . Stratified ______ tissues 1. Involve two or more layers of cells 2. New cells regenerate from below - Basal cells divide and migrate toward surface 3. More durable than simple epithelia because protection is the major role . Stratified squamous ______ 1. Most widespread of stratified epithelia 2. Free surface is squamous, with deeper cuboidal or columnar layers 3. Located in areas of high wear and tear (example: skin) 4. Keratinized cells found in skin; nonkeratinized cells are found in moist linings . Stratified cuboidal _______ 1. Quite rare 2. Found in some sweat and mammary glands 3. Typically only two cell layers thick . Stratified columnar _______ 1. Also very limited distribution in body 2. Small amounts found in pharynx, in male urethra, and lining some glandular ducts 3. Usually occurs at transition areas between two other types of epithelia 4. Only apical layer is columnar . Transitional ______ 1. Forms lining of hollow urinary organs - Found in bladder, ureters, and urethra 2. Basal layer cells are cuboidal or columnar 3. Ability of cells to change shape when stretched allows for increased flow of urine and, in the case of bladder, more storage space • Blood - Most atypical connective tissue because it is fluid • Consists of cells surrounded by matrix (plasma) - Red blood cells are most common cell type - Also contains white blood cells and platelets - Fibers are soluble proteins that precipitate during blood clotting - Functions in transport and in carrying nutrients, wastes, gases, and other substances

Epithelial Tissue

Forms boundaries between different environments, protects, secretes, absorbs, filters Lining of digestive tract organs and other hollow organs Skin surface (epidermis)

Epithelial Tissue

. Nail fold that projects onto surface of nail body - Also called cuticle

Eponychium

• Fever, hypertension, inflammation, allergy . Redness

Erythema

Energy for Contraction and ATP • For a muscle to return to its pre-exercise state: - Oxygen reserves are replenished - Lactic acid is reconverted to pyruvic acid - Glycogen stores are replaced - ATP and creatine phosphate reserves are resynthesized • All replenishing steps require extra oxygen, so this is referred to as excess postexercise oxygen consumption (EPOC) - Formerly referred to as "oxygen debt"

Excess Postexercise Oxygen Consumption

Muscle Tissue . (responsiveness): ability to receive and respond to stimuli

Excitability

What are the four main characteristics of muscles?

Excitability Contractility Extensibility Elasticity

Muscle Fiber Contraction • Events that transmit AP along sarcolemma (excitation) are coupled to sliding of myofilaments (contraction) • AP is propagated along sarcolemma and down into T tubules, where voltage-sensitive proteins in tubules stimulate Ca2+ release from SR - Ca2+ release leads to contraction • AP is brief and ends before contraction is seen

Excitation Contraction Coupling

Removal of wastes from metabolism and digestion • Urea (from breakdown of proteins), carbon dioxide (from metabolism), feces (unabsorbed foods)

Excretion

• Skin can secrete limited amounts of nitrogenous wastes, such as ammonia, urea, and uric acid • Sweating can cause salt and water loss

Excretion

Glandular Epithelia . Externally secreting (example: sweat) . Secretions are released onto body surfaces, such as skin, or into body cavities . More numerous than endocrine glands . Secrete products into ducts . Examples include mucous, sweat, oil, and salivary glands

Exocrine

Muscle Tissue . Ability to be stretched

Extensibility

Angular Movements . Increases the angle of the joint

Extension

Synovial Joints Outside the capsule

Extracapsular

Force of Muscle Contractions • Force of contraction depends on number of cross bridges attached, which is affected by four factors: 1. Number of muscle fibers stimulated (recruitment): the more motor units recruited, the greater the force. 2. Relative size of fibers: the bulkier the muscle, the more tension it can develop • Muscle cells can increase in size (hypertrophy) with regular exercise 3. Frequency of stimulation: the higher the frequency, the greater the force • Stimuli are added together 4. Degree of muscle stretch: muscle fibers with sarcomeres that are 80-120% their normal resting length generate more force • If sarcomere is less than 80% resting length, filaments overlap too much, and force decreases • If sarcomere is greater than 120% of resting length, filaments do not overlap enough so force decreases • How fast a muscle contracts and how long it can stay contracted is influenced by: - Muscle fiber type - Load - Recruitment • Muscle fiber type - Classified according to two characteristics 1. Speed of contraction - slow or fast fibers according to: - Speed at which myosin ATPases split ATP - Pattern of electrical activity of motor neurons 2. Metabolic pathways used for ATP synthesis - Oxidative fibers: use aerobic pathways - Glycolytic fibers: use anaerobic glycolysis - Based on these two criteria, skeletal muscle fibers can be classified into three types: • Slow oxidative fibers, fast oxidative fibers, or fast glycolytic fibers - Most muscles contain mixture of fiber types, resulting in a range of contractile speed and fatigue resistance • All fibers in one motor unit are the same type • Genetics dictate individual's percentage of each - Different muscle types are better suited for different jobs • Slow oxidative fibers: low-intensity, endurance activities - Example: maintaining posture • Fast oxidative fibers: medium-intensity activities - Example: sprinting or walking • Fast glycolytic fibers: short-term intense or powerful movements - Example: hitting a baseball • Load and recruitment - Load: muscles contract fastest when no load is added • The greater the load, the shorter the duration of contraction • The greater the load, the slower the contraction - Recruitment: the more motor units contracting, the faster and more prolonged the contraction

Factors of Muscle Contraction

Factors of Muscle Contraction Velocity and Duration of Contraction Muscle Fiber Type . Short-term intense or powerful movements - Example: hitting a baseball

Fast Glycolytic Fibers

Factors of Muscle Contraction Velocity and Duration of Contraction Muscle Fiber Type . Medium-intensity activities - Example: sprinting or walking

Fast Oxidative Fibers

Connective Tissue Store nutrients

Fat Cells

Long-term energy storage

Fats

Female Reproductive System

Knee Joint • Plane joint • Allows gliding motion during knee flexion

Femoropatellar Joint

What are the three joints in the knee joint?

Femoropatellar Lateral Medial

Blast Cells Found in connective tissue proper

Fibroblasts

Cartilage • Properties between hyaline and dense regular tissue • Strong, so found in areas such as intervertebral discs and knee Description:Matrix similar to but less firm than that in hyaline cartilage; thick collagen fibers predominate. Function:Tensile strength allows it to absorb compressive shock. Location:Intervertebraldiscs; pubic symphysis; discs of knee joint.

Fibrocartilage

•Thick collagen fibers: has great tensile strength •Menisci of knee; vertebral discs

Fibrocartilage

• Osteoblasts form spongy bone within matrix - This mass of repair tissue is called

Fibrocartilaginous Callus

- Capillaries grow into hematoma - Phagocytic cells clear debris - Fibroblasts secrete collagen fibers to span break and connect broken ends - Fibroblasts, cartilage, and osteogenic cells begin reconstruction of bone • Create cartilage matrix of repair tissue • Osteoblasts form spongy bone within matrix - This mass of repair tissue is called _________ ___________

Fibrocartilaginous Callus Formation

Connective tissue replaces destroyed tissue, and original function lost

Fibrosis

What are the three types based on what material binds the joints and whether a cavity is present?

Fibrous Cartilaginous Synovial

• Bones joined by dense fibrous connective tissue • No joint cavity • Most are immovable - Depends on length of connective tissue fibers • Three types of _______ _______ - Sutures - Syndesmoses - Gomphoses . Sutures • Rigid, interlocking joints of skull • Allow for growth during youth - Contain short connective tissue fibers that allow for expansion • In middle age, sutures ossify and fuse - Immovable joints join skull into one unit that protects brain - Closed, immovable sutures referred to as synostoses • Bones connected by ligaments, bands of fibrous tissue • Fiber length varies, so movement varies - Short fibers offer little to no movement • Example: inferior tibiofibular _____ - Longer fibers offer a larger amount of movement • Example: interosseous membrane connecting radius and ulna . Gomphoses • Peg-in-socket ______ • Only examples are the teeth in alveolar sockets • Fibrous connection is the periodontal ligament - Holds tooth in socket

Fibrous Joints

. Outer layer consisting of dense irregular connective tissue consisting of Sharpey's fibers that secure to bone matrix

Fibrous Layer

Knee Joint . Prevent rotation when knee is extended

Fibular and Tibial Collateral Ligaments

. Burns • Epidermal damage only - Localized redness, edema (swelling), and pain

First Degree

What are the three classifications of burns?

First degree Second degree Third degree

• Severed blood vessels bleed. • Inflammatory chemicals are released by injured tissue cells, mast cells, and others. • Local blood vessels become more permeable, allowing white blood cells, fluid, clotting proteins, and other plasma proteins to seep into the injured area. • Clotting occurs; surface exposed to air dries and forms a scab.

First step of Tissue Repair

Tissue is preserved with solvent

Fixed

. Of reticular layer are dermal folds at or near joints - Dermis is tightly secured to deeper structures - Skin's inability to slide easily for joint movement causes deep creases - Visible on hands, wrists, fingers, soles, toes

Flexure Lines

. Breaks - During youth, most fractures result from trauma - In old age, most result from weakness of bone due to bone thinning • Three "either/or" _______ classifications - Position of bone ends after fracture • Nondisplaced: ends retain normal position • Displaced: ends are out of normal alignment - Completeness of break • Complete: broken all the way through • Incomplete: not broken all the way through - Whether skin is penetrated • Open (compound): skin is penetrated • Closed (simple): skin is not penetrated • Can also be described by location of ________, external appearance, and nature of break • Treatment involves reduction, the realignment of broken bone ends - Closed reduction: physician manipulates to correct position - Open reduction: surgical pins or wires secure ends - Immobilization of bone by cast or traction is needed for healing • Time needed for repair depends on break severity, bone broken, and age of patient • Repair involves four major stages: 1. Hematoma formation 2. Fibrocartilaginous callus formation 3. Bony callus formation 4. Bone remodeling 1. Hematoma formation - Torn blood vessels hemorrhage, forming mass of clotted blood called a hematoma - Site is swollen, painful, and inflamed 2. Fibrocartilaginous callus formation - Capillaries grow into hematoma - Phagocytic cells clear debris - Fibroblasts secrete collagen fibers to span break and connect broken ends - Fibroblasts, cartilage, and osteogenic cells begin reconstruction of bone • Create cartilage matrix of repair tissue • Osteoblasts form spongy bone within matrix - This mass of repair tissue is called fibrocartilaginous callus 3. Bony callus formation - Within one week, new trabeculae appear in fibrocartilaginous callus - Callus is converted to bony (hard) callus of spongy bone - Bony callus formation continues for about 2 months until firm union forms 4. Bone remodeling - Begins during bony callus formation and continues for several months - Excess material on diaphysis exterior and within medullary cavity is removed - Compact bone is laid down to reconstruct shaft walls - Final structure resembles original structure • Responds to same mechanical stressors

Fractures

Factors of Muscle Contraction . The higher the frequency, the greater the force • Stimuli are added together

Frequency of Stimulation

Coronal -Divides body vertically into anterior and posterior parts (front and back) -Produces a frontal or coronal section

Frontal Plane

. Three types based on movement ______ allows • Synarthroses: immovable joints • Amphiarthroses: slightly movable joints • Diarthroses: freely movable joints

Functional Classification

Muscle Fiber Contraction • Resting sarcolemma is polarized, meaning a voltage exists across membrane - Inside of cell is negative compared to outside • Action potential is caused by changes in electrical charges • Occurs in three steps 1. End plate potential 2. Depolarization 3. Repolarization 1. End plate potential - ACh released from motor neuron binds to ACh receptors on sarcolemma - Causes chemically gated ion channels (ligands) on sarcolemma to open - Na+ diffuses into muscle fiber • Some K+ diffuses outward, but not much - Because Na+ diffuses in, interior of sarcolemma becomes less negative (more positive) - Results in local depolarization called end plate potential 2. Depolarization: generation and propagation of an action potential (AP) - If end plate potential causes enough change in membrane voltage to reach critical level called threshold, voltage-gated Na+ channels in membrane will open - Large influx of Na+ through channels into cell triggers AP that is unstoppable and will lead to muscle fiber contraction - AP spreads across sarcolemma from one voltage-gated Na+ channel to next one in adjacent areas, causing that area to depolarize 3. Repolarization: restoration of resting conditions - Na+ voltage-gated channels close, and voltage- gated K+ channels open - K+ efflux out of cell rapidly brings cell back to initial resting membrane voltage - Refractory period: muscle fiber cannot be stimulated for a specific amount of time, until repolarization is complete - Ionic conditions of resting state are restored by Na+-K+ pump • Na+ that came into cell is pumped back out, and K+ that flowed outside is pumped back into cell

Generation of an Action Potential Across the Sarcolemma

. Gland 1. One or more cells that makes and secretes an aqueous fluid called a secretion . Classified by: 1. Site of product release: - Endocrine: internally secreting (example: hormones) - Exocrine: externally secreting (example: sweat) 2. Relative number of cells forming the gland - Unicellular (example: goblet cells) or multicellular (example: salivary) . Endocrine glands 1. Ductless glands - Secretions are not released into a duct; are released into surrounding interstitial fluid, which is picked up by circulatory system 2. Secrete (by exocytosis) hormones, messenger chemicals that travel through lymph or blood to their specific target organs 3. Target organs respond in some characteristic way . Exocrine glands 1. Secretions are released onto body surfaces, such as skin, or into body cavities 2. More numerous than endocrine glands 3. Secrete products into ducts 4. Examples include mucous, sweat, oil, and salivary glands . Unicellular exocrine glands 1. The only important unicellular glands are mucous cells and goblet cells 2. Found in epithelial linings of intestinal and respiratory tracts 3. All produce mucin, a sugar-protein that can dissolve in water to form mucus, a slimy protective, lubricating coating . Multicellular exocrine glands 1. Multicellular exocrine glands are composed of a duct and a secretory unit 2. Usually surrounded by supportive connective tissue that supplies blood and nerve fibers to gland -Connective tissue can form capsule around gland, and also extend into gland, dividing it into lobes . Multicellular exocrine glands 1. Mode of secretion - Merocrine: most secrete products by exocytosis as secretions are produced (sweat, pancreas) - Holocrine: accumulate products within, then rupture (sebaceous oil glands) - Apocrine: accumulate products within, but only apex ruptures; whether this type exists in humans is controversial (maybe mammary cells?)

Glandular Epithelia

Secretory tissue in glands (example: salivary glands)

Glandular Epithelia

Thickened basal lamina

Glassy Membrane

Shoulder Joint . Fibrocartilaginous rim around glenoid cavity - Helps to add depth to shallow cavity - Cavity still only holds one-third of head of humerus

Glenoid Labrum

What are the three general types of movement in synovial joints?

Gliding Angular movements Rotation

Jaw Joint . Side-to-side (lateral excursion) grinding of teeth

Gliding Movement

• Synovial Joints Movement - One flat bone surface glides or slips over another similar surface - Examples • Intercarpal joints • Intertarsal joints • Between articular processes of vertebrae

Gliding Movements

Factors of Muscle Contraction Velocity and Duration of Contraction Muscle Fiber Type . Use anaerobic glycolysis

Glycolytic Fibers

• Peg-in-socket joints • Only examples are the teeth in alveolar sockets • Fibrous connection is the periodontal ligament - Holds tooth in socket

Gomphoses

- Deposition of uric acid crystals in joints and soft tissues, followed by inflammation - More common in men - Typically affects joint at base of great toe - In untreated ______ ______, bone ends fuse and immobilize joint - Treatment: drugs, plenty of water, avoidance of alcohol and foods high in purines, such as liver, kidneys, and sardines

Gouty Arthritis

Whole Muscle Contractions • Normal muscle contraction is relatively smooth, and strength varies with needs - A muscle twitch is seen only in lab setting or with neuromuscular problems, but not in normal muscle • Graded muscle responses vary strength of contraction for different demands - Required for proper control of skeletal movement • Responses are graded by: - Changing frequency of stimulation - Changing strength of stimulation • Muscle response to changes in stimulus frequency - Single stimulus results in single contractile response (i.e., muscle twitch) - Wave (temporal) summation results if two stimuli are received by a muscle in rapid succession • Muscle fibers do not have time to completely relax between stimuli, so twitches increase in force with each stimulus • Additional Ca2+ that is released with second stimulus stimulates more shortening • Produces smooth, continuous contractions that add up (summation) • Further increase in stimulus frequency causes muscle to progress to sustained, quivering contraction referred to as unfused (incomplete) tetanus - If stimuli frequency increases, muscle tension reaches maximum • Referred to as fused (complete) tetanus because contractions "fuse" into one smooth sustained contraction plateau • Prolonged muscle contractions lead to muscle fatigue - Recruitment (or multiple motor unit summation): stimulus is sent to more muscle fibers, leading to more precise control - Types of stimulus involved in recruitment: • Subthreshold stimulus: stimulus not strong enough, so no contractions seen • Threshold stimulus: stimulus is strong enough to cause first observable contraction • Maximal stimulus: strongest stimulus that increases maximum contractile force - All motor units have been recruited - Recruitment works on size principle • Motor units with smallest muscle fibers are recruited first • Motor units with larger and larger fibers are recruited as stimulus intensity increases • Largest motor units are activated only for most powerful contractions • Motor units in muscle usually contract asynchronously - Some fibers contract while others rest - Helps prevent fatigue

Graded Muscle Response

- Torn blood vessels hemorrhage, forming mass of clotted blood called a hematoma - Site is swollen, painful, and inflamed

Hematoma Formation

•Compact and spongy bone -Compact bone: dense outer layer on every bone that appears smooth and solid -Spongy bone: made up of a honeycomb of small, needle-like or flat pieces of bone called trabeculae •Open spaces between trabeculae are filled with red or yellow bone marrow •Structure of short, irregular, and flat bones -Consist of thin plates of spongy bone (diploe) covered by compact bone -Compact bone sandwiched between connective tissue membranes •Periosteum covers outside of compact bone, and endosteum covers inside portion of compact bone -Bone marrow is scattered throughout spongy bone; no defined marrow cavity -Hyaline cartilage covers area of bone that is part of a movable joint •Structure of typical long bone -All long bones have a shaft (diaphysis), bone ends (epiphyses), and membranes •Diaphysis: tubular shaft that forms long axis of bone -Consists of compact bone surrounding central medullary cavity that is filled with yellow marrow in adults •Epiphyses: ends of long bones that consist of compact bone externally and spongy bone internally -Articular cartilage covers articular (joint) surfaces •Between diaphysis and epiphysis is epiphyseal line -Remnant of childhood epiphyseal plate where bone growth occurs •Membranes: two types (periosteum and endosteum) -Periosteum: white, double-layered membrane that covers external surfaces except joints » Fibrous layer: outer layer consisting of dense irregular connective tissue consisting of Sharpey's fibers that secure to bone matrix » Osteogenic layer: inner layer abutting bone and contains primitive osteogenic stem cells that gives rise to most all bone cells » Contains many nerve fibers and blood vessels that continue on to the shaft through nutrient foramen openings » Anchoring points for tendons and ligaments -Endosteum » Delicate connective tissue membrane covering internal bone surface » Covers trabeculae of spongy bone » Lines canals that pass through compact bone » Like periosteum, contains osteogenic cells that can differentiate into other bone cells •Hematopoietic tissue in bones -Red marrow is found within trabecular cavities of spongy bone and diploë of flat bones, such as sternum •In newborns, medullary cavities and all spongy bone contain red marrow •In adults, red marrow is located in heads of femur and humerus, but most active areas of hematopoiesis are flat bone diploë and some irregular bones (such as the hip bone) •Yellow marrow can convert to red, if person becomes anemic •Bone markings -Sites of muscle, ligament, and tendon attachment on external surfaces -Areas involved in joint formation or conduits for blood vessels and nerves

Gross Anatomy

What are the three levels of structure in a bone?

Gross Microscopic Chemical

- Unstructured gel-like material that fills space between cells • Medium through which solutes diffuse between blood capillaries and cells - Components • Interstitial fluid • Cell adhesion proteins ("glue" for attachment) • Proteoglycans (sugar proteins), made up of protein core + large polysaccharides - Example: chrondroitin sulfate and hyaluronic acid • Water also is trapped in varying amounts, affecting viscosity of ground substance

Ground Substance

What are the three main elements of connective tissue?

Ground substance Fibers Cells

- Increase in size of a body part or of organism

Growth

Skeletal Muscle Fibers Myofibrils Striations A Bands . Lighter region in middle of dark A band

H Zone

• Consists of dead keratinized cells • None located on palms, soles, lips, nipples, and portions of external genitalia • Functions: - Warn of insects on skin - ___ on head guards against physical trauma - Protect from heat loss - Shield skin from sunlight • ____ (also called pili): flexible strands of dead, keratinized cells • Produced by ____ follicles • Contains hard keratin, not like soft keratin found in skin - Hard keratin is tougher and more durable, and cells do not flake off • Regions: - Shaft: area that extends above scalp, where keratinization is complete - Root: area within scalp, where keratinization is still going on • _____ pigments are made by melanocytes in hair follicles - Combinations of different melanins (yellow, rust, brown, black) create all the hair colors • Red hair has additional pheomelanin pigment • Gray/white hair results when melanin production decreases and air bubbles replace melanin in shaft • Extends from epidermal surface to dermis • ____ bulb: expanded area at deep end of follicle • ___ follicle receptor (or root ____ plexus): sensory nerve endings that wrap around bulb - _____ is considered a sensory touch receptor • Wall of follicle composed of: - Peripheral connective tissue sheath • Derived from dermis • Also called fibrous sheath - Glassy membrane: thickened basal lamina - Epithelial root sheath • ____ matrix: actively dividing area of bulb that produces hair cells - As matrix makes new cells, it pushes older ones upward • Arrector pili: small band of smooth muscle attached to follicle - Responsible for "goose bumps" • _____ papilla - Dermal tissue containing a knot of capillaries that supplies nutrients to growing ____ • Vellus _____: pale, fine body hair of children and adult females • Terminal _____: coarse, long _____ - Found on scalp and eyebrows - At puberty • Appear in axillary and pubic regions of both sexes • Also on face and neck of males • Nutrition and hormones affect _____ growth • Follicles cycle between active and regressive phases - Average 2.25 mm growth per week - Lose 90 scalp _____ daily • Alopecia: hair thinning in both sexes after age 40 • True (frank) baldness - Genetically determined and sex -influenced condition - Male pattern baldness caused by follicular response to DHT (dihydrotestosterone) • Hair thinning can be induced by several factors: - Acutely high fever - Surgery - Severe emotional trauma - Certain drugs (such as antidepressants, blood thinners, steroids, and chemotherapeutic drugs) - Protein -deficient diets - Alopecia areata: immune system attacks follicles - Some hair loss is reversible, but others (such as from burns or radiation) are permanent

Hair

Expanded area at deep end of follicle

Hair Bulb

. Sensory nerve endings that wrap around bulb - Hair is considered a sensory touch receptor

Hair Follicle Receptor

. Actively dividing area of bulb that produces hair cells - As matrix makes new cells, it pushes older ones upward

Hair Matrix

Dermal tissue containing a knot of capillaries that supplies nutrients to growing hair

Hair Papillae

• _____ ______ can be induced by several factors: - Acutely high fever - Surgery - Severe emotional trauma - Certain drugs (such as antidepressants, blood thinners, steroids, and chemotherapeutic drugs) - Protein-deficient diets - Alopecia areata: immune system attacks follicles - Some hair loss is reversible, but others (such as from burns or radiation) are permanent

Hair thinning

Pericardium

Heart

What are the four major stages of fracture repair?

Hematoma formation Fibrocartilaginous callus formation Bony callus formation Bone remodeling

Occurs in red marrow cavities of certain bones

Hematopoiesis

-Red marrow is found within trabecular cavities of spongy bone and diploë of flat bones, such as sternum •In newborns, medullary cavities and all spongy bone contain red marrow •In adults, red marrow is located in heads of femur and humerus, but most active areas of hematopoiesis are flat bone diploë and some irregular bones (such as the hip bone) •Yellow marrow can convert to red, if person becomes anemic

Hematopoietic Tissue

• Pinkish hue of fair skin is due to lower levels of melanin - Skin of Caucasians is more transparent, so color of hemoglobin shows through

Hemoglobin

What are the two types of movement in the jaw joint?

Hinge Gliding

Jaw Joint . Depression and elevation of mandible

Hinge Movement

• Ball-and-socket joint • Large, spherical head of the femur articulates with deep cup-shaped acetabulum • Good range of motion, but limited by the deep socket - Acetabular labrum: rim of fibrocartilage that enhances depth of socket (hip dislocations are rare) • Reinforcing ligaments include: - Iliofemoral ligament - Pubofemoral ligament - Ischiofemoral ligament - Ligament of head of femur (ligamentum teres) • Slack during most hip movements, so not important in stabilizing • Does contain artery that supplies head of femur • Greatest stability comes from deep ball-and-socket joint

Hip Joint

Microscopic study of tissues

Histology

Study of tissues

Histology

Multicellular Exocrine Glands Accumulate products within, then rupture (sebaceous oil glands)

Holocrine

The maintenance of relatively stable internal conditions despite continuous changes in environment - A dynamic state of equilibrium, always readjusting as needed - Maintained by contributions of all organ systems

Homeostasis

• Disturbance of homeostasis - Increases risk of disease - Contributes to changes associated with aging • Control systems become less efficient - If negative feedback mechanisms become overwhelmed, destructive positive feedback mechanisms may take over . Heart Failure

Homeostatic Imbalance

• Negative feedback loop that controls blood Ca2+ levels • Calcium functions in many processes, such as nerve transmission, muscle contraction, blood coagulation, gland and nerve secretions, as well as cell division • 99% of 1200-1400 gms of calcium are found in bone • Intestinal absorption of Ca2+ requires vitamin D - Parathyroid hormone (PTH): produced by parathyroid glands in response to low blood calcium levels • Stimulates osteoclasts to resorb bone • Calcium is released into blood, raising levels • PTH secretion stops when homeostatic calcium levels are reached - Calcitonin: produced by parafollicular cells of thyroid gland in response to high levels of blood calcium levels • Effects are negligible, but at high pharmacological doses it can lower blood calcium levels temporarily - Other _______ play a role in bone density and turnover • Leptin - ________ released by adipose tissue - May play role in bone density regulation by inhibiting osteoblasts • Serotonin - Neurotransmitter regulates mood and sleep; also interferes with osteoblast activity - Most serotonin made in gut - Secreted into blood after a meal - May inhibit bone turnover after a meal, so bone calcium is locked in when new calcium is flooding into bloodstream

Hormonal Controls

• Growth hormone: most important hormone in stimulating epiphyseal plate activity in infancy and childhood • Thyroid hormone: modulates activity of growth hormone, ensuring proper proportions • Testosterone (males) and estrogens (females) at puberty: promote adolescent growth spurts - End growth by inducing epiphyseal plate closure • Excesses or deficits of any hormones cause abnormal skeletal growth

Hormonal Regulation of Bone Growth

What are the two control groups of bone remodeling?

Hormonal Response to mechanical stress

Smooth Muscle Contraction of Smooth Muscle Regulation of Contraction • Some smooth muscle cells have no nerve supply - Depolarize spontaneously or in response to chemical stimuli that bind to G protein-linked receptors - Chemical factors can include hormones, high CO2, pH, low oxygen • Some smooth muscles respond to both neural and chemical stimuli

Hormones and Local Chemicals

_____ ____ is very organized, from the smallest chemical level to whole organism level: - Chemical level: atoms, molecules, and organelles - Cellular level: single cell - Tissue level: groups of similar cells - Organ level: contains two or more types of tissues - Organ system level: organs that work closely together - Organismal level: all organ systems combined to make the whole organism

Human Body

Cartilage • Most abundant; "gristle" • Appears as shiny bluish glass • Found at tips of long bones, nose, trachea, larynx, and cartilage of the ribs Description:Amorphous but firm matrix; collagen fibers form an imperceptible network; chondroblasts produce the matrix and when mature (chondrocytes) lie in lacunae. Function:Supports and reinforces; serves as resilient cushion; resists compressive stress. Location:Forms most of the embryonic skeleton; covers the ends of long bones in joint cavities; forms costal cartilages of the ribs; cartilages of the nose, trachea, and larynx.

Hyaline

•Provides support, flexibility, and resilience •Most abundant type; contains collagen fibers only •Articular (joints), costal (ribs), respiratory (larynx), nasal cartilage (nose tip)

Hyaline Cartilage

What are the three types of cartilage?

Hyaline Elastic Fibrocartilage

•Makeup 65% of bone by mass •Consist mainly of tiny calcium phosphate crystals in and around collagen fibers •Responsible for hardness and resistance to compression

Hydroxyapatites

Angular Movements Movement beyond the anatomical position

Hyperextension

- Area with older chondrocytes closer to diaphysis - Cartilage lacunae enlarge and erode, forming interconnecting spaces

Hypertrophic Zone

• Even minute changes in blood calcium levels can cause severe neuromuscular problems - __________: low levels of calcium cause hyperexcitablility - ___________: high levels of calcium cause nonresponsiveness - Sustained high blood calcium levels can lead to deposits of _____ ______ in blood vessels or kidneys and formation of kidney stones

Hypocalcemia Hypercalcemia Calcium salts

. Superficial fascia • Subcutaneous layer deep to skin • Not part of skin but shares some functions • Mostly adipose tissue that absorbs shock and insulates • Anchors skin to underlying structures: mostly muscles

Hypodermis

. Area under free edge of plate that accumulates dirt

Hyponychium

Skeletal Muscle Fibers Myofibrils Striations . Lighter regions

I Bands

What are the reinforcing ligaments in a hip joint?

Iliofemoral Pubofemoral Ischiofemoral Ligament of head of femur

• Time needed for repair depends on break severity, bone broken, and age of patient

Immobilization

Fracture Not broken all the way through

Incomplete

Skeletal Muscle Tissue Attachments . Connective tissue wrappings extend beyond muscle as ropelike tendon or sheetlike aponeurosis

Indirect

Caudal Away from the head end or toward the lower part of a structure or body

Inferior

•Serous membranes can become ______ as a result of infection or other causes •Normally smooth layers can become ______ and even can stick together, resulting in excruciating pain •Examples: pleurisy and peritonitis

Inflamed Rough

What is the first step to tissue repair?

Inflammation

• Bursitis - Inflammation of bursa, usually caused by blow or friction - Treated with rest and ice and, if severe, anti-inflammatory drugs • Tendonitis - Inflammation of tendon sheaths, typically caused by overuse - Symptoms and treatment similar to those of bursitis • Arthritis - >100 different types of inflammatory or degenerative diseases that damage joints - Most widespread crippling disease in the U.S. - Symptoms: pain, stiffness, and swelling of joint - Acute forms: caused by bacteria, treated with antibiotics - Chronic forms: osteoarthritis, rheumatoid arthritis, and gouty arthritis • Osteoarthritis (OA) - Most common type of arthritis - Irreversible, degenerative ("wear-and-tear") arthritis - May reflect excessive release of enzymes that break down articular cartilage • Cartilage is broken down faster than it is replaced • Bone spurs (osteophytes) may form from thickened ends of bones - By age 85, half of Americans develop OA, more women than men • Rheumatoid arthritis (RA) - Chronic, inflammatory, autoimmune disease of unknown cause • Immune system attacks own cells - Usually arises between ages 40 and 50, but may occur at any age; affects three times as many women as men - Signs and symptoms include joint pain and swelling (usually bilateral), anemia, osteoporosis, muscle weakness, and cardiovascular problems - RA begins with inflammation of synovial membrane (synovitis) of affected joint - Inflammatory blood cells migrate to joint, release inflammatory chemicals that destroy tissues - Synovial fluid accumulates, causing joint swelling - Inflamed synovial membrane thickens into abnormal pannus tissue that clings to articular cartilage - Pannus erodes cartilage, scar tissue forms and connects articulating bone ends (ankylosis) • Gouty arthritis - Deposition of uric acid crystals in joints and soft tissues, followed by inflammation - More common in men - Typically affects joint at base of great toe - In untreated gouty arthritis, bone ends fuse and immobilize joint - Treatment: drugs, plenty of water, avoidance of alcohol and foods high in purines, such as liver, kidneys, and sardines • Lyme disease - Caused by bacteria transmitted by tick bites - Symptoms: skin rash, flu-like symptoms, and foggy thinking - May lead to joint pain and arthritis - Treatment • Long course of antibiotics

Inflammatory and Degenerative Conditions

-Hydroxyapatites (mineral salts) •Makeup 65% of bone by mass •Consist mainly of tiny calcium phosphate crystals in and around collagen fibers •Responsible for hardness and resistance to compression -Bone is half as strong as steel in resisting compression and as strong as steel in resisting tension -Lasts long after death because of mineral composition -Can reveal information about ancient people

Inorganic Components

Under normal, resting body temperature, sweat glands produce about 500 ml/day of unnoticeable sweat

Insensible Perspiration

Anatomy and physiology are _______ - Function always reflects ______ - What a structure can do depends on its specific _____ - Known as the principle of ______ ____ _______ ____ ______

Inseparable Structure Form Complementarity of Structure and Function

Skeletal Muscle Tissue Attachments . Attachment to movable bone

Insertion

What are the two places muscles attach to bones?

Insertion Origin

• ________: sole of foot faces medially • _________: sole of foot faces laterally

Inversion and Eversion

•Complicated shapes •Vertebrae and hip bones

Irregular Bones

Whole Muscle Contraction . No shortening; muscle tension increases but does not exceed load

Isometric Contraction

Whole Muscle Contractions Isotonic and Isometric Contractions - Load is greater than the maximum tension muscle can generate, so muscle neither shortens nor lengthens

Isometric Contractions

What are the two types of muscle contractions?

Isometric Isotonic

Whole Muscle Contraction . Muscle shortens because muscle tension exceeds load

Isotonic Contraction

Whole Muscle Contractions Isotonic and Isometric Contractions . Muscle changes in length and moves load - Isotonic contractions can be either concentric or eccentric: • Concentric contractions: muscle shortens and does work - Example: biceps contract to pick up a book • Eccentric contractions: muscle lengthens and generates force - Example: laying a book down causes biceps to lengthen while generating a force

Isotonic Contractions

Whole Muscle Contractions • Isotonic contractions: muscle changes in length and moves load - Isotonic contractions can be either concentric or eccentric: • Concentric contractions: muscle shortens and does work - Example: biceps contract to pick up a book • Eccentric contractions: muscle lengthens and generates force - Example: laying a book down causes biceps to lengthen while generating a force • Isometric contractions - Load is greater than the maximum tension muscle can generate, so muscle neither shortens nor lengthens • Electrochemical and mechanical events are same in isotonic or isometric contractions, but results are different - In isotonic contractions, actin filaments shorten and cause movement - In isometric contractions, cross bridges generate force, but actin filaments do not shorten • Myosin heads "spin their wheels" on same actin- binding site

Isotonic and Isometric Contractions

• Liver disorders . Yellow cast

Jaundice

Temporomandibular Joint TMJ

Jaw Joint

• ______ ______ is a modified hinge joint • Mandibular condyle articulates with temporal bone - Posterior temporal bone forms mandibular fossa, while anterior portion forms articular tubercle • Articular capsule thickens into strong lateral ligament • Two types of movement - Hinge: depression and elevation of mandible - Gliding: side-to-side (lateral excursion) grinding of teeth • Most easily dislocated joint in the body • Dislocation of TMJ is most common because of shallow socket of joint • Almost always dislocates anteriorly, causing mouth to remain open - To realign, physician must push mandible back into place • Symptoms: ear and face pain, tender muscles, popping sounds when opening mouth, joint stiffness • Usually caused by grinding teeth, but can also be due to jaw trauma or poor occlusion of teeth - Treatment for grinding teeth includes bite plate - Relaxing jaw muscles helps

Jaw Joint

Whole Muscle Contraction Muscle Twitch . Events of excitation-contraction coupling • No muscle tension seen

Latent Period

What are the three phases of a muscle twitch?

Latent period Period of contraction Period of relaxation

Away from the midline of the body

Lateral

Rotation . Rotation away from midline

Lateral

Knee Joint • ________ and ________ joints together are called tibiofemoral joint • Joint between femoral condyles and lateral and _______ menisci of tibia • Hinge joint that allows flexion, extension, and some rotation when knee partly flexed

Lateral and Medial Joint

Smooth Muscle Contraction of Smooth Muscle Special Features of Smooth Muscle Contraction • Can contract when between half and twice its resting length - Allows organ to have huge volume changes without becoming flabby when relaxed

Length and Tension Changes

Hip Joint • Slack during most hip movements, so not important in stabilizing • Does contain artery that supplies head of femur

Ligament of Head of Femur

Factors of Muscle Contraction Velocity and Duration of Contraction Load and Recruitment . Muscles contract fastest when no load is added • The greater the load, the shorter the duration of contraction • The greater the load, the slower the contraction

Load

- Caused by bacteria transmitted by tick bites - Symptoms: skin rash, flu-like symptoms, and foggy thinking - May lead to joint pain and arthritis - Treatment • Long course of antibiotics

Lyme Disease

Factors of Muscle Contraction Velocity and Duration of Contraction - Load: muscles contract fastest when no load is added • The greater the load, the shorter the duration of contraction • The greater the load, the slower the contraction - Recruitment: the more motor units contracting, the faster and more prolonged the contraction

Load and Recruitment

•Longer than they are wide •Limb bones -All ____ _____ have a shaft (diaphysis), bone ends (epiphyses), and membranes •Diaphysis: tubular shaft that forms long axis of bone -Consists of compact bone surrounding central medullary cavity that is filled with yellow marrow in adults •Epiphyses: ends of long bones that consist of compact bone externally and spongy bone internally -Articular cartilage covers articular (joint) surfaces •Between diaphysis and epiphysis is epiphyseal line -Remnant of childhood epiphyseal plate where bone growth occurs -Endosteum » Delicate connective tissue membrane covering internal _____ surface » Covers trabeculae of spongy ______ » Lines canals that pass through compact _____ » Like periosteum, contains osteogenic cells that can differentiate into other ______ cells• Interstitial growth requires presence of epiphyseal cartilage in the epiphyseal plate • Epiphyseal plate maintains constant thickness - Rate of cartilage growth on one side balanced by bone replacement on other • Epiphyseal plate consists of five zones: 1. Resting (quiescent) zone 2. Proliferation (growth) zone 3. Hypertrophic zone 4. Calcification zone 5. Ossification (osteogenic) zone 1. Resting (quiescent) zone - Area of cartilage on epiphyseal side of epiphyseal plate that is relatively inactive 2. Proliferation (growth) zone - Area of cartilage on diaphysis side of epiphyseal plate that is rapidly dividing - New cells formed move upward, pushing epiphysis away from diaphysis, causing lengthening 3. Hypertrophic zone - Area with older chondrocytes closer to diaphysis - Cartilage lacunae enlarge and erode, forming interconnecting spaces 4. Calcification zone - Surrounding cartilage matrix calcifies; chondrocytes die and deteriorate 5. Ossification zone - Chondrocyte deterioration leaves long spicules of calcified cartilage at epiphysis-diaphysis junction - Spicules are then eroded by osteoclasts and are covered with new bone by osteoblasts - Ultimately replaced with spongy bone - Medullary cavity enlarges as spicules are eroded • Near end of adolescence, chondroblasts divide less often • Epiphyseal plate thins, then is replaced by bone • Epiphyseal plate closure occurs when epiphysis and diaphysis fuse • Bone lengthening ceases - Females: occurs around 18 years of age - Males: occurs around 21 years of age • Growing bones widen as they lengthen through appositional growth - Can occur throughout life • Bones thicken in response to increased stress from muscle activity or added weight • Osteoblasts beneath periosteum secrete bone matrix on external bone • Osteoclasts remove bone on endosteal surface • Usually more building up than breaking down which leads to thicker, stronger bone that is not too heavy

Long Bones

What are the four types of bones in the body?

Long Short Flat Irregular

What are the two layers in smooth muscle?

Longitudinal Circular

Smooth Muscle Microscopic Structure . Fibers run parallel to long axis of organ • Contraction causes organ to shorten

Longitudinal Layer

What are the two subclasses for connective tissue proper?

Loose Dense

. Thickened nail matrix, appears white

Lunule

Whole Muscle Contractions Graded Muscle Response Changing Frequency of Stimulation . Strongest stimulus that increases maximum contractile force - All motor units have been recruited

Maximal Stimulus

Rotation . Rotation toward midline

Medial

Toward or at the midline of the body

Medial

Median •Cut was made perfectly on midline

Medial Plane

Contains pericardial cavity Surrounds other thoracic organs, such as esophagus, trachea, etc.

Mediastinum

What are the three pigments of the skin?

Melanin

• Only pigment made in skin; made by melanocytes - Packaged into melanosomes that are sent to keratinocytes to shield DNA from sunlight - Sun exposure stimulates _____ production • Two forms: reddish yellow to brownish black • All humans have same number of keratinocytes, so color differences are due to amount and form of ______ • Freckles and pigmented moles are local accumulations of ______

Melanin

• Spider-shaped cells located in deepest epidermis • Produce pigment melanin, which is packaged into melanosomes - Melanosomes are transferred to keratinocytes, where they protect nucleus from UV damage

Melanocytes

Multicellular Exocrine Glands Most secrete products by exocytosis as secretions are produced (sweat, pancreas)

Merocrine

Simple Squamous Epithelia Serous membranes in the ventral body cavity

Mesothelium

• Skin can synthesize vitamin D needed for calcium absorption in intestine • Chemicals from keratinocytes can disarm some carcinogens • Keratinocytes can activate some hormones - Example: convert cortisone into hydrocortisone • Skin makes collagenase, which aids in natural turnover of collagen to prevent wrinkles

Metabolic Functions

All chemical reactions that occur in body cells • Sum of all catabolism (breakdown of molecules) and anabolism (synthesis of molecules)

Metabolism

Deals with structures too small to be seen by naked eye • Cytology: microscopic study of cells • Histology: microscopic study of tissues

Microscopic Anatomy

Whole Muscle Contraction . Nerve-muscle functional unit • Consists of the motor neuron and all muscle fibers (four to several hundred) it supplies - Smaller the fiber number, the greater the fine control • Muscle fibers from a motor unit are spread throughout the whole muscle, so stimulation of a single motor unit causes only weak contraction of entire muscle

Motor Unit

Smooth Muscle • Spindle-shaped fibers: thin and short compared with skeletal muscle fibers - Only one nucleus, no striations • Lacks connective tissue sheaths - Contains endomysium only • All but smallest blood vessels contain smooth muscle organized into two layers of opposing sheets of fibers - Longitudinal layer: fibers run parallel to long axis of organ • Contraction causes organ to shorten - Circular layer: fibers run around circumference of organ • Contraction causes lumen of organ to constrict • Allows peristalsis: alternating contractions and relaxations of layers mix and squeeze substances through lumen of hollow organs • No neuromuscular junction, as in skeletal muscle • Instead, autonomic nerve fibers innervate smooth muscle - Contain varicosities (bulbous swellings) of nerve fibers - Varicosities store and release neurotransmitters into a wide synaptic cleft referred to as a diffuse junction • Smooth muscle does not contain sarcomeres, myofibrils, or T tubules • SR is less developed than in skeletal muscle - SR does store intracellular Ca2+, but most calcium used for contraction has extracellular origins • Sarcolemma contains pouchlike infoldings called caveolae - Caveolae contain numerous Ca2+ channels that open to allow rapid influx of extracellular Ca2+ • Smooth muscle also differs from skeletal muscle in following ways: - Thick filaments are fewer and have myosin heads along entire length • Ratio of thick to thin filaments (1:13) is much lower than in skeletal muscle (1:2) • Thick filaments have heads along entire length, making smooth muscle as powerful as skeletal muscle - No troponin complex • Does contain tropomyosin, but not troponin • Protein calmodulin binds Ca2+ - Thick and thin filaments arranged diagonally • Myofilaments are spirally arranged, causing smooth muscle to contract in corkscrew manner - Intermediate filament-dense body network • Contain lattice-like arrangement of noncontractile intermediate filaments that resist tension • Dense bodies: proteins that anchor filaments to sarcolemma at regular intervals - Correspond to Z discs of skeletal muscle • During contraction, areas of sarcolemma between dense bodies bulge outward - Make muscle cell look puffy

Microscopic Structure

Fingerlike Projections

Microvilli

Involved in chemical reactions as well as for structural purposes

Minerals and Vitamins

• Body must constantly be ______ and regulated to maintain homeostasis - _____ and _____ ______, as well as other systems, play a major role in maintaining homeostasis - Variables are factors that can ____ (blood sugar, body temperature, blood volume, etc.)

Monitored Nervous Endocrine systems Change

Sugar-protein that can dissolve in water to form mucus, a slimy protective, lubricating coating.

Mucin

What are two important unicellular glands?

Mucous Goblet

• Mucosa indicates location, not cell composition • Also called mucosae - Line body cavities that are open to the exterior (example: digestive, respiratory, urogenital tracts) • Moist membranes bathed by secretions (or urine) • Epithelial sheet lies over layer of loose connective tissue called lamina propria • May secrete mucus

Mucous Membranes

Synovial Joints Movement . Movement in or around all three planes

Multiaxial

. Composed of a duct and a secretory unit . Usually surrounded by supportive connective tissue that supplies blood and nerve fibers to gland 1. Connective tissue can form capsule around gland, and also extend into gland, dividing it into lobes . Mode of secretion 1. Merocrine: most secrete products by exocytosis as secretions are produced (sweat, pancreas) 2. Holocrine: accumulate products within, then rupture (sebaceous oil glands) 3. Apocrine: accumulate products within, but only apex ruptures; whether this type exists in humans is controversial (maybe mammary cells?)

Multicellular Exocrine Glands

• Humans are ______, so to function, individual cells must be kept alive - Organ systems are designed to _____ the cells - All cells depend on organ systems to meet their survival _____ • There are ___ organ systems that work together to maintain life

Multicellular Service Needs 11

Smooth Muscle Types of Smooth Muscle - Located in large airways in lungs, large arteries, arrector pili muscles, and iris of eye - Very few gap junctions, and spontaneous depolarization is rare - Similar to skeletal muscle in some features • Consists of independent muscle fibers • Innervated by autonomic nervous system, forming motor units • Graded contractions occur in response to neural stimuli that involve recruitment - Different from skeletal muscle because, like unitary smooth muscle, it is controlled by autonomic nervous system and hormones

Multiunit Smooth Muscle

Energy for Contraction and ATP • Physiological inability to contract despite continued stimulation • Usually occurs when there are ionic imbalances - Levels of K+, Ca2+, Pi can interfere with E-C coupling - Prolonged exercise may also damage SR and interferes with Ca2+ regulation and release • Lack of ATP is rarely a reason for fatigue, except in severely stressed muscles

Muscle Fatigue

• Four steps must occur for skeletal muscle to contract: 1. Nerve stimulation 2. Action potential, an electrical current, must be generated in sarcolemma 3. Action potential must be propagated along sarcolemma 4. Intracellular Ca2+ levels must rise briefly • Steps 1 and 2 occur at neuromuscular junction • Steps 3 and 4 link electrical signals to contraction, so referred to as excitation-contraction coupling • Skeletal muscles are stimulated by somatic motor neurons • Axons (long, threadlike extensions of motor neurons) travel from central nervous system to skeletal muscle • Each axon divides into many branches as it enters muscle • Axon branches end on muscle fiber, forming neuromuscular junction or motor end plate - Each muscle fiber has one neuromuscular junction with one motor neuron • Axon terminal (end of axon) and muscle fiber are separated by gel-filled space called synaptic cleft • Stored within axon terminals are membrane-bound synaptic vesicles - Synaptic vesicles contain neurotransmitter acetylcholine (ACh) • Infoldings of sarcolemma, called junctional folds, contain millions of ACh receptors • NMJ consists of axon terminals, synaptic cleft, and junctional folds • Events at the neuromuscular junction - Nerve impulse arrives at axon terminal, causing ACh to be released into synaptic cleft - ACh diffuses across cleft and binds with receptors on sarcolemma - ACh binding leads to electrical events that ultimately generate an action potential through muscle fiber - ACh is quickly broken down by enzyme acetylcholinesterase, which stops contractions • Many toxins, drugs, and diseases interfere with events at the neuromuscular junction - Example: myasthenia gravis: disease characterized by drooping upper eyelids, difficulty swallowing and talking, and generalized muscle weakness - Involves shortage of Ach receptors because person's ACh receptors are attacked by own antibodies - Suggests this is an autoimmune disease • Resting sarcolemma is polarized, meaning a voltage exists across membrane - Inside of cell is negative compared to outside • Action potential is caused by changes in electrical charges • Occurs in three steps 1. End plate potential 2. Depolarization 3. Repolarization 1. End plate potential - ACh released from motor neuron binds to ACh receptors on sarcolemma - Causes chemically gated ion channels (ligands) on sarcolemma to open - Na+ diffuses into muscle fiber • Some K+ diffuses outward, but not much - Because Na+ diffuses in, interior of sarcolemma becomes less negative (more positive) - Results in local depolarization called end plate potential 2. Depolarization: generation and propagation of an action potential (AP) - If end plate potential causes enough change in membrane voltage to reach critical level called threshold, voltage-gated Na+ channels in membrane will open - Large influx of Na+ through channels into cell triggers AP that is unstoppable and will lead to muscle fiber contraction - AP spreads across sarcolemma from one voltage-gated Na+ channel to next one in adjacent areas, causing that area to depolarize 3. Repolarization: restoration of resting conditions - Na+ voltage-gated channels close, and voltage- gated K+ channels open - K+ efflux out of cell rapidly brings cell back to initial resting membrane voltage - Refractory period: muscle fiber cannot be stimulated for a specific amount of time, until repolarization is complete - Ionic conditions of resting state are restored by Na+-K+ pump • Na+ that came into cell is pumped back out, and K+ that flowed outside is pumped back into cell • Excitation-contraction (E-C) coupling: events that transmit AP along sarcolemma (excitation) are coupled to sliding of myofilaments (contraction) • AP is propagated along sarcolemma and down into T tubules, where voltage-sensitive proteins in tubules stimulate Ca2+ release from SR - Ca2+ release leads to contraction • AP is brief and ends before contraction is seen • Nerve impulse travels down axon of motor neuron • When impulse reaches axon terminal, voltage-gated calcium channels open, and Ca2+ enters axon terminal • Ca2+ influx causes synaptic vesicle to exocytose Ach into synaptic cleft • ACh binds to receptors on sarcolemma, causing chemically gated Na+-K+ channels to open and initiate an end plate potential • When threshold is reached, voltage-gated Na+ channels open, initiating an AP • At low intracellular Ca2+ concentration: - Tropomyosin blocks active sites on actin - Myosin heads cannot attach to actin - Muscle fiber remains relaxed • Voltage-sensitive proteins in T tubules change shape, causing SR to release Ca2+ to cytosol • At higher intracellular Ca2+ concentrations, Ca2+ binds to troponin • Troponin changes shape and moves tropomyosin away from myosin-binding sites • Myosin heads is then allowed to bind to actin, forming cross bridge • Cycling is initiated, causing sarcomere shortening and muscle contraction • When nervous stimulation ceases, Ca2+ is pumped back into SR, and contraction ends • Four steps of the cross bridge cycle 1. Cross bridge formation: high-energy myosin head attaches to actin thin filament active site 2. Working (power) stroke: myosin head pivots and pulls thin filament toward M line 3. Cross bridge detachment: ATP attaches to myosin head, causing cross bridge to detach 4. Cocking of myosin head: energy from hydrolysis of ATP "cocks" myosin head into high-energy state • This energy will be used for power stroke in next cross bridge cycle • Rigor mortis - 3-4 hours after death, muscles begin to stiffen • Peak rigidity occurs about 12 hours postmortem - Intracellular calcium levels increase because ATP is no longer being synthesized, so calcium cannot be pumped back into SR • Results in cross bridge formation - ATP is also needed for cross bridge detachment • Results in myosin head staying bound to actin, causing constant state of contraction - Muscles stay contracted until muscle proteins break down, causing myosin to release

Muscle Fiber Contraction

Muscle Fiber Contraction • At low intracellular Ca2+ concentration: - Tropomyosin blocks active sites on actin - Myosin heads cannot attach to actin - Muscle fiber remains relaxed • Voltage-sensitive proteins in T tubules change shape, causing SR to release Ca2+ to cytosol • At higher intracellular Ca2+ concentrations, Ca2+ binds to troponin • Troponin changes shape and moves tropomyosin away from myosin-binding sites • Myosin heads is then allowed to bind to actin, forming cross bridge • Cycling is initiated, causing sarcomere shortening and muscle contraction • When nervous stimulation ceases, Ca2+ is pumped back into SR, and contraction ends • Four steps of the cross bridge cycle 1. Cross bridge formation: high-energy myosin head attaches to actin thin filament active site 2. Working (power) stroke: myosin head pivots and pulls thin filament toward M line 3. Cross bridge detachment: ATP attaches to myosin head, causing cross bridge to detach 4. Cocking of myosin head: energy from hydrolysis of ATP "cocks" myosin head into high-energy state • This energy will be used for power stroke in next cross bridge cycle

Muscle Fiber Contraction: Cross Bridge Cycling

• Skeletal muscle fibers are long, cylindrical cells that contain multiple nuclei • Sarcolemma: muscle fiber plasma membrane • Sarcoplasm: muscle fiber cytoplasm • Contains many glycosomes for glycogen storage, as well as myoglobin for O2 storage • Modified organelles - Myofibrils - Sarcoplasmic reticulum - T tubules • Myofibrils are densely packed, rodlike elements - Single muscle fiber can contain 1000s - Accounts for ~80% of muscle cell volume • Myofibril features - Striations - Sarcomeres - Myofilaments - Molecular composition of myofilaments • Striations: stripes formed from repeating series of dark and light bands along length of each myofibril - A bands: dark regions • H zone: lighter region in middle of dark A band - M line: line of protein (myomesin) that bisects H zone vertically - I bands: lighter regions • Z disc (line): coin-shaped sheet of proteins on midline of light I band • Sarcomere - Smallest contractile unit (functional unit) of muscle fiber - Contains A band with half of an I band at each end • Consists of area between Z discs - Individual sarcomeres align end to end along myofibril, like boxcars of train • Myofilaments - Orderly arrangement of actin and myosin myofilaments within sarcomere - Actin myofilaments: thin filaments • Extend across I band and partway in A band • Anchored to Z discs - Myosin myofilaments: thick filaments • Extend length of A band • Connected at M line - Sarcomere cross section shows hexagonal arrangement of one thick filament surrounded by six thin filaments • Molecular composition of myofilaments - Thick filaments: composed of protein myosin that contains two heavy and four light polypeptide chains • Heavy chains intertwine to form myosin tail • Light chains form myosin globular head - During contraction, heads link thick and thin filaments together, forming cross bridges • Myosins are offset from each other, resulting in staggered array of heads at different points along thick filament - Thin filaments: composed of fibrous protein actin • Actin is polypeptide made up of kidney-shaped G actin (globular) subunits - G actin subunits bears active sites for myosin head attachment during contraction • G actin subunits link together to form long, fibrous F actin (filamentous) • Two F actin strands twist together to form a thin filament - Tropomyosin and troponin: regulatory proteins bound to actin - Other proteins help form the structure of the myofibril • Elastic filament: composed of protein titin - Holds thick filaments in place; helps recoil after stretch; resists excessive stretching • Dystrophin - Links thin filaments to proteins of sarcolemma • Nebulin, myomesin, C proteins bind filaments or sarcomeres together - Maintain alignment of sarcomere • Sarcoplasmic reticulum: network of smooth endoplasmic reticulum tubules surrounding each myofibril - Most run longitudinally - Terminal cisterns form perpendicular cross channels at the A-I band junction - SR functions in regulation of intracellular Ca2+ levels - Stores and releases Ca2+ • T tubules - Tube formed by protrusion of sarcolemma deep into cell interior • Increase muscle fiber's surface area greatly • Lumen continuous with extracellular space • Allow electrical nerve transmissions to reach deep into interior of each muscle fiber - Tubules penetrate cell's interior at each A-I band junction between terminal cisterns • Triad: area formed from terminal cistern of one sarcomere, T tubule, and terminal cistern of neighboring sarcomere • Triad relationships - T tubule contains integral membrane proteins that protrude into intermembrane space (space between tubule and muscle fiber sarcolemma) • Tubule proteins act as voltage sensors that change shape in response to an electrical current - SR cistern membranes also have integral membrane proteins that protrude into intermembrane space • SR integral proteins control opening of calcium channels in SR cisterns - When an electrical impulse passes by, T tubule proteins change shape, causing SR proteins to change shape, causing release of calcium into cytoplasm • Contraction: the activation of cross bridges to generate force • Shortening occurs when tension generated by cross bridges on thin filaments exceeds forces opposing shortening • Contraction ends when cross bridges become inactive • In the relaxed state, thin and thick filaments overlap only slightly at ends of A band • Sliding filament model of contraction states that during contraction, thin filaments slide past thick filaments, causing actin and myosin to overlap more - Neither thick nor thin filaments change length, just overlap more • When nervous system stimulates muscle fiber, myosin heads are allowed to bind to actin, forming cross bridges, which cause sliding (contraction) process to begin • Cross bridge attachments form and break several times, each time pulling thin filaments a little closer toward center of sarcome in a ratcheting action - Causes shortening of muscle fiber • Z discs are pulled toward M line • I bands shorten • Z discs become closer • H zones disappear • A bands move closer to each other

Muscle Fiber Microanatomy and Sliding Filament Model

As the fast-acting control system of the body, it responds to internal and external changes by activating appropriate muscles and glands.

Nervous System

Internal communication Brain Spinal Cord Nerves

Nervous Tissue

Factors of Muscle Contraction Velocity and Duration of Contraction - Classified according to two characteristics 1. Speed of contraction - slow or fast fibers according to: - Speed at which myosin ATPases split ATP - Pattern of electrical activity of motor neurons 2. Metabolic pathways used for ATP synthesis - Oxidative fibers: use aerobic pathways - Glycolytic fibers: use anaerobic glycolysis - Based on these two criteria, skeletal muscle fibers can be classified into three types: • Slow oxidative fibers, fast oxidative fibers, or fast glycolytic fibers - Most muscles contain mixture of fiber types, resulting in a range of contractile speed and fatigue resistance • All fibers in one motor unit are the same type • Genetics dictate individual's percentage of each - Different muscle types are better suited for different jobs • Slow oxidative fibers: low-intensity, endurance activities - Example: maintaining posture • Fast oxidative fibers: medium-intensity activities - Example: sprinting or walking • Fast glycolytic fibers: short-term intense or powerful movements - Example: hitting a baseball

Muscle Fiber Type

Only skeletal and smooth muscle cells are elongated and referred to as what?

Muscle Fibers

• Four important _______ 1. Produce movement: responsible for all locomotion and manipulation • Example: walking, digesting, pumping blood 2. Maintain posture and body position 3. Stabilize joints 4. Generate heat as they contract • Additional functions - Protect organs, form valves, control pupil size, cause "goosebumps"

Muscle Functions

Whole Muscle Contraction . The force exerted on load or object to be moved

Muscle Tension

Contracts to cause movement Muscles attached to bones (skeletal) Muscles of heart (cardiac) Muscles of walls of hollow organs (smooth)

Muscle Tissue

• Highly vascularized • Responsible for most types of movement - _____ cells possess myofilaments made up of actin and myosin proteins that bring about contraction • Three types of _____ tissues: - Skeletal _____ - Cardiac _____ - Smooth _____ • Skeletal ______ tissue - Attached to and causes movement of bones - Also called voluntary muscle • Skeletal ______ can be consciously controlled - Cells are called _______ fibers • Contain multiple nuclei • Appear striated or banded • Cardiac ______ tissue - Found only in walls of heart - Involuntary ______ - Like skeletal ______, contains striations; but cells have only one nucleus - Cells can have many branches that join branches of other cardiac cells • Intercalated discs are special joints where cardiac cells are joined • Smooth ______ tissue - Found mainly in walls of hollow organs (other than heart) - Involuntary _____ - Has no visible striations - Spindle-shaped cells with one nucleus • Main component of nervous system (brain, spinal cord, nerves) - Regulates and controls body functions • Made up of two specialized cells: - Neurons: specialized nerve cells that generate and conduct nerve impulses - Supporting cells that support, insulate, and protect neurons

Muscle Tissue

• Terminologies: Myo, mys, and sarco are prefixes for muscle - Example: sarcoplasm: muscle cell cytoplasm • Three types of ______ ______ - Skeletal - Cardiac - Smooth • Only skeletal and smooth muscle cells are elongated and referred to as muscle fibers • Skeletal muscle - Skeletal muscle tissue is packaged into skeletal muscles: organs that are attached to bones and skin - Skeletal muscle fibers are longest of all muscle and have striations (stripes) - Also called voluntary muscle: can be consciously controlled - Contract rapidly; tire easily; powerful - Key words for skeletal muscle: skeletal, striated, and voluntary • Cardiac muscle - Cardiac muscle tissue is found only in heart • Makes up bulk of heart walls - Striated - Involuntary: cannot be controlled consciously • Contracts at steady rate due to heart's own pacemaker, but nervous system can increase rate - Key words for cardiac muscle: cardiac, striated, and involuntary • Smooth muscle - Smooth muscle tissue: found in walls of hollow organs • Examples: stomach, urinary bladder, and airways - Not striated - Involuntary: cannot be controlled consciously • Can contract on its own without nervous system stimulation • All muscles share four main characteristics: - Excitability (responsiveness): ability to receive and respond to stimuli - Contractility: ability to shorten forcibly when stimulated - Extensibility: ability to be stretched - Elasticity: ability to recoil to resting length • Four important functions 1. Produce movement: responsible for all locomotion and manipulation • Example: walking, digesting, pumping blood 2. Maintain posture and body position 3. Stabilize joints 4. Generate heat as they contract • Additional functions - Protect organs, form valves, control pupil size, cause "goosebumps"

Muscle Tissue

Whole Muscle Contractions • Constant, slightly contracted state of all muscles • Due to spinal reflexes - Groups of motor units are alternately activated in response to input from stretch receptors in muscles • Keeps muscles firm, healthy, and ready to respond

Muscle Tone

Whole Muscle Contraction • Simplest contraction resulting from a muscle fiber's response to a single action potential from motor neuron - Muscle fiber contracts quickly, then relaxes • Twitch can be observed and recorded as a myogram - Tracing: line recording contraction activity • Three phases of ______ ______ - Latent period: events of excitation-contraction coupling • No muscle tension seen - Period of contraction: cross bridge formation • Tension increases - Period of relaxation: Ca2+ reentry into SR • Tension declines to zero • Muscle contracts faster than it relaxes • Differences in strength and duration of twitches are due to variations in metabolic properties and enzymes between muscles - Example: eye muscles contraction are rapid and brief, whereas larger, fleshy muscles (calf muscles) contract more slowly and hold it longer

Muscle Twitch

Factors of Muscle Contraction • How fast a muscle contracts and how long it can stay contracted is influenced by:

Muscle fiber type Load Recruitment

• ________ _______: group of inherited muscle-destroying diseases - Generally appear in childhood • Muscles enlarge as a result of fat and connective tissue deposits, but then atrophy and degenerate • Duchenne muscular dystrophy (DMD) is the most common and severe type - Caused by defective gene for dystrophin - Inherited, sex-linked trait, carried by females and expressed in males (1/3600) - Dystrophin is a cytoplasmic protein that links the cytoskeleton to the extracellular matrix, stabilizing the sarcolemma • Fragile sarcolemma tears during contractions, causing entry of excess Ca2+ - Leads to damaged contractile fibers • Inflammatory cells accumulate • Muscle mass declines • Victims become clumsy and fall frequently - Usually appears between ages 2 and 7 - Currently no cure is known - Prednisone can improve muscle strength and function - Myoblast transfer therapy has been disappointing - Coaxing dystrophic muscles to produce more utrophin (protein similar to dystrophin) has been successful in mice - Viral gene therapy and infusion of stem cells with correct dystrophin genes show promise • Patients usually die of respiratory failure in their early 20s

Muscular Dystrophy

Allows manipulation of the environment, locomotion, and facial expression. Maintains posture, and produces heat.

Muscular System

Skeletal Muscle Fibers • _________ are densely packed, rodlike elements - Single muscle fiber can contain 1000s - Accounts for ~80% of muscle cell volume • _________ features - Striations - Sarcomeres - Myofilaments - Molecular composition of myofilaments • Striations: stripes formed from repeating series of dark and light bands along length of each myofibril - A bands: dark regions • H zone: lighter region in middle of dark A band - M line: line of protein (myomesin) that bisects H zone vertically - I bands: lighter regions • Z disc (line): coin-shaped sheet of proteins on midline of light I band • Sarcomere - Smallest contractile unit (functional unit) of muscle fiber - Contains A band with half of an I band at each end • Consists of area between Z discs - Individual sarcomeres align end to end along __________, like boxcars of train • Myofilaments - Orderly arrangement of actin and myosin myofilaments within sarcomere - Actin myofilaments: thin filaments • Extend across I band and partway in A band • Anchored to Z discs - Myosin myofilaments: thick filaments • Extend length of A band • Connected at M line - Sarcomere cross section shows hexagonal arrangement of one thick filament surrounded by six thin filaments • Molecular composition of myofilaments - Thick filaments: composed of protein myosin that contains two heavy and four light polypeptide chains • Heavy chains intertwine to form myosin tail • Light chains form myosin globular head - During contraction, heads link thick and thin filaments together, forming cross bridges • Myosins are offset from each other, resulting in staggered array of heads at different points along thick filament - Thin filaments: composed of fibrous protein actin • Actin is polypeptide made up of kidney-shaped G actin (globular) subunits - G actin subunits bears active sites for myosin head attachment during contraction • G actin subunits link together to form long, fibrous F actin (filamentous) • Two F actin strands twist together to form a thin filament - Tropomyosin and troponin: regulatory proteins bound to actin - Other proteins help form the structure of the _________ • Elastic filament: composed of protein titin - Holds thick filaments in place; helps recoil after stretch; resists excessive stretching • Dystrophin - Links thin filaments to proteins of sarcolemma • Nebulin, myomesin, C proteins bind filaments or sarcomeres together - Maintain alignment of sarcomere

Myofibrils

What are the modified organelles in skeletal muscle fibers?

Myofibrils Sarcoplasmic reticulum T tubules

- Orderly arrangement of actin and myosin myofilaments within sarcomere - Actin myofilaments: thin filaments • Extend across I band and partway in A band • Anchored to Z discs - Myosin myofilaments: thick filaments • Extend length of A band • Connected at M line - Sarcomere cross section shows hexagonal arrangement of one thick filament surrounded by six thin filaments • Molecular composition of __________ - Thick filaments: composed of protein myosin that contains two heavy and four light polypeptide chains • Heavy chains intertwine to form myosin tail • Light chains form myosin globular head - During contraction, heads link thick and thin filaments together, forming cross bridges • Myosins are offset from each other, resulting in staggered array of heads at different points along thick filament - Thin filaments: composed of fibrous protein actin • Actin is polypeptide made up of kidney-shaped G actin (globular) subunits - G actin subunits bears active sites for myosin head attachment during contraction • G actin subunits link together to form long, fibrous F actin (filamentous) • Two F actin strands twist together to form a thin filament - Tropomyosin and troponin: regulatory proteins bound to actin - Other proteins help form the structure of the myofibril • Elastic filament: composed of protein titin - Holds thick filaments in place; helps recoil after stretch; resists excessive stretching • Dystrophin - Links thin filaments to proteins of sarcolemma • Nebulin, myomesin, C proteins bind filaments or sarcomeres together - Maintain alignment of sarcomere

Myofilaments

Skeletal Muscle Fibers Myofibrils Myofilaments . Thick filaments • Extend length of A band • Connected at M line

Myosin Myofilaments

Factors of Muscle Contraction . The more motor units recruited, the greater the force.

Number of Muscle Fibers Stimulated

• Scale-like modifications of epidermis that contain hard keratin • Act as a protective cover for distal, dorsal surface of fingers and toes • Consist of free edge, ______ plate, and root • _____ bed is epidermis underneath keratinized ____ plate • _____ matrix: thickened portion of bed responsible for ____ growth • ____ folds: skin folds that overlap border of ____ • Eponychium: nail fold that projects onto surface of ____ body - Also called cuticle • Hyponychium: area under free edge of plate that accumulates dirt • _____ normally appear pink because of underlying capillaries - Lunule: thickened nail matrix, appears white • Abnormal color or shape can be an indicator of disease

Nail

. Thickened portion of bed responsible for ____ growth

Nail Matrix

Response either reduces stimulus - Most-used feedback mechanism in body - Response reduces or shuts off original stimulus • Variable changes in opposite direction of initial change - Examples • Regulation of body temperature (a nervous system mechanism) • Regulation of blood glucose by insulin (an endocrine system mechanism) - Receptors sense increased blood glucose (blood sugar) - Pancreas (control center) secretes insulin into the blood - Insulin causes body cells (effectors) to absorb more glucose, which decreases blood glucose levels

Negative Feedback

Muscle Tissue • Each muscle receives a nerve, artery, and veins - Consciously controlled skeletal muscle has nerves supplying every fiber to control activity • Contracting muscle fibers require huge amounts of oxygen and nutrients - Also need waste products removed quickly

Nerve and Blood Supply

What are the three different tissues in skeletal muscle anatomy?

Nerve and blood supply Connective tissue sheaths Attachments

What are the four steps for muscle fiber to contract?

Nerve stimulation Action potential Action potential must be propagated along sarcolemma Intracellular Ca2+ levels must rise briefly

• Nerves detect pain; monitor joint position and stretch • Capillary beds supply filtrate for synovial fluid

Nerves and Blood Vessels

• Main component of _____ _____ (brain, spinal cord, nerves) - Regulates and controls body functions • Made up of two specialized cells: - Neurons: specialized nerve cells that generate and conduct nerve impulses - Supporting cells that support, insulate, and protect neurons Description: Neurons are branching cells; cell processes that may be quite long extend from the nucleus-containing cell body; also contributing to nervous tissue are nonexcitable supporting cells. Function: Neurons transmit electrical signals from sensory receptors and to effectors (muscles and glands); supporting cells support and protect neurons. Location: Brain, spinal cord, and nerves.

Nervous Tissue

Smooth Muscle Contraction of Smooth Muscle Regulation of Contraction • Neurotransmitter binding causes either graded (local) potential or action potential - Results in increases in Ca2+ concentration in sarcoplasm - Response depends on neurotransmitter released and type of receptor molecules » One neurotransmitter can have a stimulatory effect on smooth muscle in one organ, but an inhibitory effect in a different organ

Neural Regulation

Specialized nerve cells that generate and conduct nerve impulses

Neurons

What are the two specialized cells in nervous tissue?

Neurons Supporting cells

Synovial Joints Movement . Slipping movements only

Nonaxial

What are the range of motions allowed by the synovial joints?

Nonaxial Uniaxial Biaxial Multiaxial

Fracture Ends retain normal position

Nondisplaced

What are the two parts of the position of bone ends after fracture?

Nondisplaced Displaced

- If body temp falls below or goes above 37°C, rates of chemical reactions are affected

Normal Body Temperature

What are the four ways muscle contractions are affected in force of contraction and number of cross bridges attached?

Number of muscle fibers stimulated Relative size of fibers Frequency of stimulation Degree of muscle stretch

- Chemicals for energy and cell building • Carbohydrates: major source of energy • Proteins: needed for cell building and cell chemistry • Fats: long-term energy storage • Minerals and vitamins: involved in chemical reactions as well as for structural purposes

Nutrients

What are the survival needs for humans?

Nutrients Oxygen Water Normal body temperature Appropriate atmospheric pressure

• ______ and ______ affect hair growth • Follicles cycle between active and regressive phases - Average 2.25 mm growth per week - Lose 90 scalp hairs daily

Nutrition Hormones

Knee Joint . Stabilizes posterior knee joint

Oblique Popliteal Ligament

-Result of cuts at angle other than 90° to vertical plane

Oblique Section

To study anatomy, one must know anatomical terminology and be able to _______, ________, _____ and _____

Observe Manipulate Palpate Auscultate

Fracture . Compound . Skin is penetrated

Open

What are the two parts of whether the skin is penetrated in a fracture?

Open Closed

Fracture Surgical pins or wires secure ends

Open Reduction

. Hole or canal in bone that serves as passageways for blood vessels and nerves

Opening

. Movement of thumb • Example: touching thumb to tips of other fingers on same hand or any grasping movement

Opposition

What are four smaller smaller cavities exposed to the environment?

Oral and digestive Nasal Orbital Middle ear

Contains two or more types of tissues

Organ Level

Organs that work closely together

Organ System Level

Subdivisions of physiology - Based on _______ _____ (e.g., renal or cardiovascular physiology) - Often focuses on _____ and _____ levels of the body • Looks at how the body's abilities are dependent on ______ _______ in individual cells

Organ systems Cellular Molecular Chemical reactions

•Includes osteogenic cells, osteoblasts, osteocytes, bone-lining cells, osteoclasts, and osteoid -Osteoid, which makes up one-third of organic bone matrix, is secreted by osteoblasts » Consists of ground substance and collagen fibers, which contribute to high tensile strength and flexibility of bone -Resilience of bone is due to sacrificial bonds in or between collagen molecules that stretch and break to dissipate energy and prevent fractures -If no additional trauma, bonds re-form

Organic Components

What two things are bones made up of chemically?

Organic Inorganic

All organ systems combined to make the whole organism

Organismal Level

Skeletal Muscle Tissue Attachments . Attachment to immovable or less movable bone

Origin

Synovial Joints Muscles Attachment to immovable bone

Origin

What are the two points that muscles attach to in synovial joints?

Origin Insertion

. (osteogenesis) is the process of bone tissue formation - Formation of bony skeleton begins in month 2 of development - Postnatal bone growth occurs until early adulthood - Bone remodeling and repair are lifelong • Five main steps in the process of ________: 1. Bone collar forms around diaphysis of cartilage model 2. Central cartilage in diaphysis calcifies, then develops cavities 3. Periosteal bud invades cavities, leading to formation of spongy bone • Bud is made up of blood vessels, nerves, red marrow, osteogenic cells, and osteoclasts

Ossification

- Chondrocyte deterioration leaves long spicules of calcified cartilage at epiphysis-diaphysis junction - Spicules are then eroded by osteoclasts and are covered with new bone by osteoblasts - Ultimately replaced with spongy bone - Medullary cavity enlarges as spicules are eroded

Ossification Zone

- Most common type of arthritis - Irreversible, degenerative ("wear-and-tear") arthritis - May reflect excessive release of enzymes that break down articular cartilage • Cartilage is broken down faster than it is replaced • Bone spurs (osteophytes) may form from thickened ends of bones - By age 85, half of Americans develop OA, more women than men - OA is usually part of normal aging process - Joints may be stiff and make crunching noise referred to as crepitus, especially upon rising - Treatment: moderate activity, mild pain relievers, capsaicin creams • Glucosamine, chondroitin sulfate, and nutritional supplements not effective

Osteoarthritis

What are the chronic forms of arthritis?

Osteoarthritis Rheumatoid arthritis Gouty arthritis

-Bone-forming cells that secrete unmineralized bone matrix called osteoid •Osteoid is made up of collagen and calcium-binding proteins •Collagen makes up 90% of bone protein -_______ are actively mitotic

Osteoblasts

Blast Cells Found in bone

Osteoblasts

Produce matrix in the bone

Osteoblasts

Secreted by bones helps to regulate insulin secretion, glucose levels, and metabolism

Osteocalcin

-Derived from same hematopoietic stem cells that become macrophages -Giant, multinucleate cells function in bone resorption (breakdown of bone) -When active, cells are located in depressions called resorption bays -Cells have ruffled borders that serve to increase surface area for enzyme degradation of bone •Also helps seal off area from surrounding matrix

Osteoclasts

-Mature bone cells in lacunae that no longer divide -Maintain bone matrix and act as stress or strain sensors •Respond to mechanical stimuli such as increased force on bone or weightlessness •Communicate information to osteoblasts and osteoclasts (cells that destroy bone) so bone remodeling can occur

Osteocytes

Maintains the matrix in the bone Reside in cavities in matrix called lacunae

Osteocytes

-Also called osteoprogenitor cells -Mitotically active stem cells in periosteum and endosteum -When stimulated, they differentiate into osteoblasts or bone-lining cells -Some remain as ______ ______ ______

Osteogenic Cells

. Inner layer abutting bone and contains primitive ________ stem cells that gives rise to most all bone cells

Osteogenic Layer

What are the five basic cell types in bones?

Osteogenic Osteoblasts Osteocytes Bone lining Osteoclasts

which makes up one-third of organic bone matrix, is secreted by osteoblasts

Osteoid

- Bones are poorly mineralized - Osteoid is produced, but calcium salts not adequately deposited - Results in soft, weak bones - Pain upon bearing weight

Osteomalacia

What are the three major bone diseases?

Osteomalacia and rickets Osteoporosis Pagets disease

•(Haversian system) -An _____ is the structural unit of compact bone -Consists of an elongated cylinder that runs parallel to long axis of bone •Acts as tiny weight-bearing pillars -An ______ cylinder consists of several rings of bone matrix called lamellae •Lamellae contain collagen fibers that run in different directions in adjacent rings •Withstands stress and resist twisting •Bone salts are found between collagen fibers

Osteon

What three things does compact bone consist of?

Osteon Canals and canaliculi Interstitial and circumferential lamella

Individual structural units in the bone tissue

Osteons

• Is a group of diseases in which bone resorption exceeds deposit • Matrix remains normal, but bone mass declines - Spongy bone of spine and neck of femur most susceptible • Vertebral and hip fractures common • Risk factors for ________ - Most often aged, postmenopausal women • Affects 30% of women aged 60-70 years and 70% by age 80 • 30% of Caucasian women will fracture bone because of osteoporosis • Estrogen plays a role in bone density, so when levels drop at menopause, women run higher risk - Men are less prone due to protection by the effects of testosterone • Additional risk factors for osteoporosis: - Petite body form - Insufficient exercise to stress bones - Diet poor in calcium and protein - Smoking - Hormone-related conditions • Hyperthyroidism • Low blood levels of thyroid-stimulating hormone • Diabetes mellitus - Immobility - Males with prostate cancer taking androgen-suppressing drugs • Treating _______ - Traditional treatments • Calcium • Vitamin D supplements • Weight-bearing exercise • Hormone replacement therapy - Slows bone loss but does not reverse it - Controversial because of increased risk of heart attack, stroke, and breast cancer • Other drugs for _________: - Bisphosphonates: decrease osteoclast activity and number • Partially reverse osteoporosis in spine - Selective estrogen receptor modulators: mimic estrogen without targeting breast and uterus - Denosumab • Monoclonal antibody shown to reduce fractures in men with prostate cancer • Improves bone density in elderly • Preventing ________ - Plenty of calcium in diet in early adulthood - Reduce consumption of carbonated beverages and alcohol • Leach minerals from bone, so decrease bone density - Plenty of weight-bearing exercise • Increases bone mass above normal for buffer against age-related bone loss

Osteoporosis

Factors of Muscle Contraction Velocity and Duration of Contraction Muscle Fiber Type . Use aerobic pathways

Oxidative Fibers

- Essential for release of energy from foods • The body can survive only a few minutes without it

Oxygen

• Excessive and haphazard bone deposit and resorption cause bone to be made fast and poorly - Called Pagetic bone - Very high ratio of spongy to compact bone and reduced mineralization • Usually occurs in spine, pelvis, femur, and skull • Rarely occurs before age 40 • Cause unknown: possibly viral • Treatment includes calcitonin and bisphosphonates

Paget's Disease

• Anemia, low blood pressure, fear, anger . Blanching or pale color

Pallor

What are the two layers of the dermis?

Papillary Reticular

•Cut was off-centered, not on midline

Parasagittal Plane

Lines internal body cavity walls

Parietal Serosa

A fist thrust into a flaccid balloon demonstrates the relationship between the ______ and _____ serous membrane layers.

Parietal Visceral

Abdominopelvic cavity

Paritoneum

. Mimic estrogen without targeting breast and uterus

Partially Reverse Osteoporosis in Spine

Contains urinary bladder, reproductive organs, and rectum

Pelvic Cavity

Canaliculi . Canals lined with endosteum that occur at right angles to central canal •Connect blood vessels and nerves of periosteum, medullary cavity, and central canal

Perforating Canals

Encloses heart

Pericardial Cavity

Heart

Pericardium

. Layer of dense connective tissue surrounding cartilage like a girdle -Helps cartilage resist outward expansion -Contains blood vessels for nutrient delivery to cartilage

Perichondrium

Connective Tissue Sheath . Fibrous connective tissue surrounding fascicles (groups of muscle fibers)

Perimysium

Whole Muscle Contraction Muscle Twitch . Cross bridge formation • Tension increases

Period of Contraction

Whole Muscle Contraction Muscle Twitch . Ca2+ reentry into SR • Tension declines to zero

Period of Relaxation

On external bone surface, lining cells

Periosteal Cells

Covers outside of compact bone,

Periosteum

White, double-layered membrane that covers external surfaces except joints » Fibrous layer: outer layer consisting of dense irregular connective tissue consisting of Sharpey's fibers that secure to bone matrix » Osteogenic layer: inner layer abutting bone and contains primitive osteogenic stem cells that gives rise to most all bone cells » Contains many nerve fibers and blood vessels that continue on to the shaft through nutrient foramen openings » Anchoring points for tendons and ligaments

Periosteum

What are the two types of membranes in gross anatomy?

Periosteum Endosteum

Smooth Muscle Microscopic Structure . Alternating contractions and relaxations of layers mix and squeeze substances through lumen of hollow organs

Peristalsis

- Flat, dead, keratinized cells of stratum corneum, surrounded by glycolipids, block most water and water-soluble substances - Some chemicals have limited penetration of skin • Lipid-soluble substances • Plant oleoresins (e.g., poison ivy) • Organic solvents (acetone, paint thinner) • Salts of heavy metals (lead, mercury) • Some drugs (nitroglycerin) • Drug agents (enhancers that help carry other drugs across skin)

Physical Barrier

To study physiology, one must understand basic ______ principles (e.g., electrical currents, pressure, and movement) as well as basic______ principles

Physical Chemical

What are the 6 different types of synovial joints?

Plane Hinge Pivot Condylar Saddle Ball-and-socket

Lungs

Pleurae

Cells have polarity (top and bottom)

Polarity

What are the five distinguishing characteristics of epithelial tissue?

Polarity Specialized contacts Supported by connective tissues Avascular but innervated Regeneration

What are three fracture classification?

Position of bone ends after fracture Completeness of break Whether skin is penetrated

Enhances stimulus - Response enhances or exaggerates the original stimulus - May exhibit a cascade or amplifying effect as feedback causes variable to continue in same direction as initial change - Usually controls infrequent events that do not require continuous adjustment, for example: • Enhancement of labor contractions by oxytocin • Platelet plug formation and blood clotting

Positive Feedback

Dorsal Toward or at the back of the body

Posterior

PCL

Posterior Cruciate Ligament

• Attaches to posterior tibia • Prevents backward sliding of tibia and forward sliding of femur

Posterior Cruciate Ligament

• Long bones grow lengthwise by interstitial (longitudinal) growth of epiphyseal plate • Bones increase thickness through appositional growth • Bones stop growing during adolescence - Some facial bones continue to grow slowly through life

Postnatal Bone Growth

What are the four muscle functions?

Produce movement Maintain posture and body position Stabilize joints Generate heat as they contract

. Outward bulge of bone -May be due to increased stress from muscle pull or is a modification for joints

Projection

- Area of cartilage on diaphysis side of epiphyseal plate that is rapidly dividing - New cells formed move upward, pushing epiphysis away from diaphysis, causing lengthening

Proliferation Zone

• Skin is exposed to microorganisms, abrasions, temperature extremes, and harmful chemicals • Constitutes three barriers: - Chemical barrier - Physical barrier - Biological barrier • Chemical barrier - Skin secretes many chemicals, such as: • Sweat, which contains antimicrobial proteins • Sebum and defensins, which kill bacteria • Cells also secrete antimicrobial defensin - Acid mantle: low pH of skin retards bacterial multiplication - Melanin provides a chemical barrier against UV radiation damage • Physical barrier - Flat, dead, keratinized cells of stratum corneum, surrounded by glycolipids, block most water and water-soluble substances - Some chemicals have limited penetration of skin • Lipid-soluble substances • Plant oleoresins (e.g., poison ivy) • Organic solvents (acetone, paint thinner) • Salts of heavy metals (lead, mercury) • Some drugs (nitroglycerin) • Drug agents (enhancers that help carry other drugs across skin) • Biological barriers - Epidermis contains phagocytic cells • Dendritic cells of epidermis engulf foreign antigens (invaders) and present to white blood cells, activating the immune response - Dermis contains macrophages • Macrophages also activate immune system by presenting foreign antigens to white blood cells - DNA can absorb harmful UV radiation, converting it to harmless heat

Protection

What are the functions of the skin?

Protection Body temperature regulation Cutaneous sensations Metabolic functions Blood reservoir Excretion of wastes

Needed for cell building and cell chemistry

Proteins

. Movement in lateral plane • _______: mandible juts out • ________: mandible is pulled toward neck

Protraction and Retraction

Closer to the origin of the body part or attachment of a limb to the body trunk

Proximal

. Cells vary in height and appear to be multi-layered and stratified, but tissue is in fact single-layered simple epithelium 1. "Pseudo" means false 2. Many cells are ciliated . Involved in secretion, particularly of mucus, and also in movement of mucus via ciliary sweeping action . Located mostly in upper respiratory tract, ducts of large glands, and tubules in testes Description: Single layer of cells of differing heights, some not reaching the free surface; nuclei seen at different levels; may contain mucus-secreting cells and bear cilia. Function: Secrete substances, particularly mucus; propulsion of mucus by ciliary action. Location: Nonciliated type in males' sperm-carrying ducts and ducts of large glands; ciliated variety lines the trachea, most of the upper respiratory tract.

Pseudostratified Columnar Epithelium

Factors of Muscle Contraction Velocity and Duration of Contraction Load and Recruitment . The more motor units contracting, the faster and more prolonged the contraction

Recruitment

Whole Muscle Contractions Graded Muscle Response Changing Frequency of Stimulation . Stimulus is sent to more muscle fibers, leading to more precise control

Recruitment

. Is found within trabecular cavities of spongy bone and diploë of flat bones, such as sternum •In newborns, medullary cavities and all spongy bone contain ____ ______ •In adults, ____ _____ is located in heads of femur and humerus, but most active areas of hematopoiesis are flat bone diploë and some irregular bones (such as the hip bone) •Yellow marrow can convert to red, if person becomes anemic

Red Marrow

. The realignment of broken bone ends - Closed ________: physician manipulates to correct position - Open ________: surgical pins or wires secure ends

Reduction

. Epithelial cells have high ________ capacities . Stimulated by loss of apical-basal polarity and broken lateral contacts . Some cells are exposed to friction, some to hostile substances, resulting in damage 1. Must be replaced 2. Requires adequate nutrients and cell division

Regeneration

Same kind of tissue replaces destroyed tissue, so original function is restored

Regeneration

Designate specific areas within body divisions

Regional Terms

Area that extends above scalp, where keratinization is complete

Regions

Which one of the epidermis layers is only found in thick skin?

Stratum Lucidum

Smooth Muscle Contraction of Smooth Muscle - Controlled by nerves, hormones, or local chemical changes - Neural regulation • Neurotransmitter binding causes either graded (local) potential or action potential - Results in increases in Ca2+ concentration in sarcoplasm - Response depends on neurotransmitter released and type of receptor molecules » One neurotransmitter can have a stimulatory effect on smooth muscle in one organ, but an inhibitory effect in a different organ - Hormones and local chemicals • Some smooth muscle cells have no nerve supply - Depolarize spontaneously or in response to chemical stimuli that bind to G protein-linked receptors - Chemical factors can include hormones, high CO2, pH, low oxygen • Some smooth muscles respond to both neural and chemical stimuli

Regulation of Contraction

Factors of Muscle Contraction . The bulkier the muscle, the more tension it can develop • Muscle cells can increase in size (hypertrophy) with regular exercise

Relative Size of Fibers

Packets of adjacent osteoblasts and osteoclasts coordinate remodeling process

Remodeling Units

Debridement

Removal

3. Restoration of resting conditions - Na+ voltage-gated channels close, and voltage- gated K+ channels open - K+ efflux out of cell rapidly brings cell back to initial resting membrane voltage - Refractory period: muscle fiber cannot be stimulated for a specific amount of time, until repolarization is complete - Ionic conditions of resting state are restored by Na+-K+ pump • Na+ that came into cell is pumped back out, and K+ that flowed outside is pumped back into cell

Repolarization

- At the cellular level, reproduction involves division of cells for growth or repair - At the organismal level, reproduction is the production of offspring

Reproduction

Adaptation to Exercise • (typically anaerobic), such as weight lifting or isometric exercises, leads to - Muscle hypertrophy • Due primarily to increase in fiber size - Increased mitochondria, myofilaments, glycogen stores, and connective tissue - Increased muscle strength and size

Resistance Exercise

When active, cells are located in depressions

Resorption Bays

Keeps blood constantly supplied with oxygen and removes carbon dioxide. The gaseous exchanges occur through the walls of the air sacs of the lungs.

Respiratory System

- Bones reflect stresses they encounter • Bones are stressed when weight bears on them or muscles pull on them - Wolf's law states that bones grow or remodel in response to demands placed on them • Stress is usually off center, so bones tend to bend • Bending compresses one side, stretches other side - Diaphysis is thickest where bending stresses are greatest - Bone can be hollow because compression and tension cancel each other out in center of bone

Response to Mechanical Stress

Smooth Muscle Contraction of Smooth Muscle Special Features of Smooth Muscle Contraction • Stress-relaxation response: responds to stretch only briefly, then adapts to new length - Retains ability to contract on demand - Enables organs such as stomach and bladder to temporarily store contents

Response to Stretch

Ability to sense and respond to stimuli • Withdrawal reflex prevents injury • Control of breathing rate, which must change in response to different activities

Responsiveness

What are the two necessary life functions?

Responsiveness Digestion

What are the 5 zones of the eliphyseal plate?

Resting Proliferation Hypertrophic Calcification Ossification

- Area of cartilage on epiphyseal side of epiphyseal plate that is relatively inactive

Resting Zone

• Short, fine, highly branched collagenous fibers (different chemistry and form from collagen fibers) • Branching forms networks that offer more "give"

Reticular

• Resembles areolar tissue, but fibers are thinner reticular fibers • Fibroblast cells are called reticular cells - Secrete reticular fibers made up of thin collagen • Reticular fibers form a mesh-like stroma that acts as a support for blood cells in lymph nodes, spleen, and bone marrow Description:Loose network of ______ fibers in a gel-like ground substance; ______ cells lie on the network. Function:Fibers form a soft internal skeleton (stroma) that supports other cell types including white blood cells, mast cells, and macrophages. Location:Lymphoid organs (lymph nodes, bone marrow, and spleen).

Reticular Connective Tissue

Deep to basal lamina Consists of network of collagen fibers

Reticular Lamina

• Makes up ~80% of dermal thickness • Consists of coarse, dense fibrous connective tissue - Many elastic fibers provide stretch-recoil properties - Collagen fibers provide strength and resiliency • Bind water, keeping skin hydrated • Extracellular matrix contains pockets of adipose cells • Cleavage (tension) lines in reticular layer are caused by many collagen fibers running parallel to skin surface - Externally invisible - Important to surgeons because incisions parallel to cleavage lines heal more readily • Flexure lines of reticular layer are dermal folds at or near joints - Dermis is tightly secured to deeper structures - Skin's inability to slide easily for joint movement causes deep creases - Visible on hands, wrists, fingers, soles, toes

Reticular Layer

- Chronic, inflammatory, autoimmune disease of unknown cause • Immune system attacks own cells - Usually arises between ages 40 and 50, but may occur at any age; affects three times as many women as men - Signs and symptoms include joint pain and swelling (usually bilateral), anemia, osteoporosis, muscle weakness, and cardiovascular problems - RA begins with inflammation of synovial membrane (synovitis) of affected joint - Inflammatory blood cells migrate to joint, release inflammatory chemicals that destroy tissues - Synovial fluid accumulates, causing joint swelling - Inflamed synovial membrane thickens into abnormal pannus tissue that clings to articular cartilage - Pannus erodes cartilage, scar tissue forms and connects articulating bone ends (ankylosis) - Treatment includes steroidal and nonsteroidal anti-inflammatory drugs to decrease pain and inflammation - Disruption of destruction of joints by immune system • Immune suppressants slow autoimmune reaction • Some agents target tumor necrosis factor to block action of inflammatory chemicals - Can replace joint with prosthesis

Rheumatoid Arthritis

. (osteomalacia of children) - Results in bowed legs and other bone deformities because bones ends are enlarged and abnormally long - Cause: vitamin D deficiency or insufficient dietary calcium

Rickets

What are the nine regions used by anatomists?

Right hypochondriac Epigastric Left hypochondriac Right lumbar Umbilical Left lumber Right Iliac Hypogastric Left iliac (inguinal)

What four quarters is the abdominopelvic region sectioned in?

Right upper Left upper Right lower Left lower

- 3-4 hours after death, muscles begin to stiffen • Peak rigidity occurs about 12 hours postmortem - Intracellular calcium levels increase because ATP is no longer being synthesized, so calcium cannot be pumped back into SR • Results in cross bridge formation - ATP is also needed for cross bridge detachment • Results in myosin head staying bound to actin, causing constant state of contraction - Muscles stay contracted until muscle proteins break down, causing myosin to release

Rigor Mortis

Area within scalp, where keratinization is still going on

Root

• Turning of bone around its own long axis, toward midline or away from it - Medial: ______ toward midline - Lateral: _______ away from midline - Examples • _______ between C1 and C2 vertebrae • ______ of humerus and femur

Rotation

Burns Body is broken into 11 sections, with each section representing 9% of body surface (except genitals, which account for 1%)

Rule of Nines

What are the three most common body planes?

Sagittal Frontal Transverse

-Divides body vertically into right and left parts -Produces a sagittal section if cut along this plane

Sagittal Plane

Muscle Fiber . Muscle fiber plasma membrane

Sarcolemma

- Smallest contractile unit (functional unit) of muscle fiber - Contains A band with half of an I band at each end • Consists of area between Z discs - Individual sarcomeres align end to end along myofibril, like boxcars of train

Sarcomere

Muscle Fiber . Muscle fiber cytoplasm

Sarcoplasm

Skeletal Muscle Fiber . Network of smooth endoplasmic reticulum tubules surrounding each myofibril - Most run longitudinally - Terminal cisterns form perpendicular cross channels at the A-I band junction - SR functions in regulation of intracellular Ca2+ levels - Stores and releases Ca2+

Sarcoplasmic Reticulum

• Network of smooth endoplasmic reticulum tubules surrounding each myofibril - Most run longitudinally - Terminal cisterns form perpendicular cross channels at the A-I band junction - SR functions in regulation of intracellular Ca2+ levels - Stores and releases Ca2+ - Tube formed by protrusion of sarcolemma deep into cell interior • Increase muscle fiber's surface area greatly • Lumen continuous with extracellular space • Allow electrical nerve transmissions to reach deep into interior of each muscle fiber - Tubules penetrate cell's interior at each A-I band junction between terminal cisterns • Triad: area formed from terminal cistern of one sarcomere, ________, and terminal cistern of neighboring sarcomere • Triad relationships - ________ contains integral membrane proteins that protrude into intermembrane space (space between tubule and muscle fiber sarcolemma) • Tubule proteins act as voltage sensors that change shape in response to an electrical current - _____ cistern membranes also have integral membrane proteins that protrude into intermembrane space • ____ integral proteins control opening of calcium channels in _____ cisterns - When an electrical impulse passes by, ___ ______ proteins change shape, causing _____ proteins to change shape, causing release of calcium into cytoplasm

Sarcoplasmic Reticulum and T Tubules

• _____ ______ may cause organs to adhere to neighboring structures, preventing normal functions • ______ can potentially cause progressive failure of the organ, particularly the heart

Scar adhesions Scarring

• _____ _____ that forms in organs, particularly the heart, can severely impair the function of that organ - May cause the organ to lose _____ capacity - May _____ substances from moving through organ - May interfere with ability of muscles to _____ or may impair nerve transmissions

Scar tissue Volume capacity Block Contract

Oil Glands

Sebaceous Glands

• Widely distributed, except for thick skin of palms and soles • Most develop from hair follicles and secrete into hair follicles • Relatively inactive until puberty - Stimulated by hormones, especially androgens • Secrete sebum - Oily holocrine secretion - Bactericidal (bacteria-killing) properties - Softens hair and skin

Sebaceous Glands

. Burns • Epidermal and upper dermal damage - Blisters appear - ______ ______ ______ burns are referred to as partial-thickness burns because only the epidermis and upper dermis are involved

Second Degree

•Organization restores blood supply - Organization begins as the blood clot is replaced with granulation tissue (new capillary- enriched tissue) - Epithelium begins to regenerate - Fibroblasts produce collagen fibers to bridge the gap until regeneration is complete - Any debris in area is phagocytized . Organization restores the blood supply: • The clot is replaced by granulation tissue, which restores the vascular supply. • Fibroblasts produce collagen fibers that bridge the gap. • Macrophages phagocytize dead and dying cells and other debris. • Surface epithelial cells multiply and migrate over the granulation tissue.

Second Step of Tissue Repair

Cut into slices thin enough to transmit light or electrons

Sectioned

-Cuts or sections made along a body plane •Named after plane, so a sagittal cut results in a sagittal section

Sections

If body temperature rises, dilation of dermal vessels can increase sweat gland activity to produce 12 L (3 gallons) of noticeable sweat

Sensible Perspiration

What are the three factors determine stability of joints to prevent dislocations

Shape of articular surface Ligament number and location Muscle tone keeps tendons taut as they cross joints

•Cube-shaped bones (in wrist and ankle) •Sesamoid bones form within tendons (example: patella) •Vary in size and number in different individuals

Short Bones

• Most freely moving joint in body • Stability is sacrificed for freedom of movement • Ball-and-socket joint - Large, hemispherical head of humerus fits in small, shallow glenoid cavity of scapula • Like a golf ball on a tee • Articular capsule enclosing cavity is also thin and loose - Contributes to freedom of movement • Glenoid labrum: fibrocartilaginous rim around glenoid cavity - Helps to add depth to shallow cavity - Cavity still only holds one-third of head of humerus • Reinforcing ligaments - Primarily on anterior aspect - Coracohumeral ligament • Helps support weight of upper limb - Three glenohumeral ligaments • Strengthen anterior capsule, but are weak support • Reinforcing muscle tendons contribute most to joint stability - Tendon of long head of biceps brachii muscle is "superstabilizer" • Travels through intertubercular sulcus • Secures humerus to glenoid cavity - Four rotator cuff tendons encircle the ______ _______ • Subscapularis • Supraspinatus • Infraspinatus • Teres minor

Shoulder Joint

. Single layer of tall, closely packed cells 1. Some cells have microvilli, and some have cilia 2. Some layers contain mucus-secreting goblet cells . Involved in absorption and secretion of mucus, enzymes, and other substances 1. Ciliated cells move mucus . Found in digestive tract, gallbladder, ducts of some glands, bronchi, and uterine tubes Description: Single layer of tall cells with round to oval nuclei; many cells bear microvilli, some bear cilia; layer may contain mucus-secreting unicellular glands (goblet cells). Function: Absorption; secretion of mucus, enzymes, and other substances; ciliated type propels mucus (or reproductive cells) by ciliary action. Location: Nonciliated type lines most of the digestive tract (stomach to rectum), gallbladder, and excretory ducts of some glands; ciliated variety lines small bronchi, uterine tubes, and some regions of the uterus.

Simple Columnar Epithelium

. Single layer of cells . Involved in secretion and absorption . Forms walls of smallest ducts of glands and many kidney tubules Description: Single layer of cubelike cells with large, spherical central nuclei Function: Secretion and absorption. Location: Kidney tubules; ducts and secretory portions of small glands; ovary surface

Simple Cuboidal Epithelium

Epithelia Are a single layer thick

Simple Epithelia

Involved in absorption, secretion, or filtration processes

Simple Epithelia

Cells are flattened laterally, and cytoplasm is sparse Function where rapid diffusion is priority Example: kidney, lungs Two special simple squamous epithelia are based on locations Endothelium: lining of lymphatic vessels, blood vessels, and heart Mesothelium: serous membranes in the ventral body cavity

Simple Squamous Epithelia

Description: Single layer of flattened cells with disc-shaped central nuclei and sparse cytoplasm; the simplest of the epithelia. Function: Allows materials to pass by diffusion and filtration in sites where protection is not important; secretes lubricating substances in serosae. Location: Kidney glomeruli; air sacs of lungs; lining of heart, blood vessels, and lymphatic vessels; lining of ventral body cavity (serosae).

Simple Squamous Epithelium

What are the first names of epithelial tissue?

Simple epithelia Stratified epithelia

Muscles attached to bones

Skeletal

- Attached to and causes movement of bones - Also called voluntary muscle • ______ ______ can be consciously controlled - Cells are called _____ fibers • Contain multiple nuclei • Appear striated or banded Description:Long, cylindrical, multinucleate cells; obvious striations. Function:Voluntary movement; locomotion; manipulation of the environment; facial expression; voluntary control. Location:In ______ ______ attached to bones or occasionally to skin.

Skeletal Muscle

- ______ _______ tissue is packaged into _______ _______: organs that are attached to bones and skin - _______ ________ fibers are longest of all muscle and have striations (stripes) - Also called voluntary muscle: can be consciously controlled - Contract rapidly; tire easily; powerful - Key words for skeletal muscle: skeletal, striated, and voluntary

Skeletal Muscle

• ______ ______ is an organ made up of different tissues with three features: nerve and blood supply, connective tissue sheaths, and attachments . Nerve and Blood Supply • Each muscle receives a nerve, artery, and veins - Consciously controlled skeletal muscle has nerves supplying every fiber to control activity • Contracting muscle fibers require huge amounts of oxygen and nutrients - Also need waste products removed quickly . Connective Tissue Sheaths • Each skeletal muscle, as well as each muscle fiber, is covered in connective tissue • Support cells and reinforce whole muscle • Sheaths from external to internal: - Epimysium: dense irregular connective tissue surrounding entire muscle; may blend with fascia - Perimysium: fibrous connective tissue surrounding fascicles (groups of muscle fibers) - Endomysium: fine areolar connective tissue surrounding each muscle fiber Attachments • Muscles span joints and attach to bones • Muscles attach to bone in at least two places - Insertion: attachment to movable bone - Origin: attachment to immovable or less movable bone • Attachments can be direct or indirect - Direct (fleshy): epimysium fused to periosteum of bone or perichondrium of cartilage - Indirect: connective tissue wrappings extend beyond muscle as ropelike tendon or sheetlike aponeurosis

Skeletal Muscle Anatomy

Long, cylindrical cells that contain multiple nuclei

Skeletal Muscle Fibers

Protects and supports body organs, and provides a framework the muscles use to cause movement. Blood cells are formed within bones. Bones store minerals.

Skeletal System

• Up to about week 8, fibrous membranes and hyaline cartilage of fetal skeleton are replaced with bone tissue • Endochondral ossification - Bone forms by replacing hyaline cartilage - Bones are called cartilage (endochondral) bones - Form most of _______ • Intramembranous ossification - Bone develops from fibrous membrane - Bones are called membrane bones • Endochondral ossification - Forms essentially all bones inferior to base of skull, except clavicles - Begins late in month 2 of development - Uses previously formed hyaline cartilage models - Requires breakdown of hyaline cartilage prior to ossification - Begins at primary ossification center in center of shaft • Blood vessels infiltrate perichondrium, converting it to periosteum • Mesenchymal cells specialize into osteoblast • Five main steps in the process of ossification: 1. Bone collar forms around diaphysis of cartilage model 2. Central cartilage in diaphysis calcifies, then develops cavities 3. Periosteal bud invades cavities, leading to formation of spongy bone • Bud is made up of blood vessels, nerves, red marrow, osteogenic cells, and osteoclasts 4. Diaphysis elongates, and medullary cavity forms • Secondary ossification centers appear in epiphyses 5. Epiphyses ossify • Hyaline cartilage remains only in epiphyseal plates and articular cartilages • Intramembranous ossification: begins within fibrous connective tissue membranes formed by mesenchymal cells - Forms frontal, parietal, occipital, temporal, and clavicle bones • Four major steps are involved in intramembranous ossification: 1. Ossification centers are formed when mesenchymal cells cluster and become osteoblasts 2. Osteoid is secreted, then calcified 3. Woven bone is formed when osteoid is laid down around blood vessels, resulting in trabeculae • Outer layer of woven bone forms periosteum 4. Lamellar bone replaces woven bone, and red marrow appears

Skeleton

• _____ consists of two distinct regions: - Epidermis: superficial region • Consists of epithelial tissue and is avascular - Dermis: underlies epidermis • Mostly fibrous connective tissue, vascular - Hypodermis (superficial fascia) • Subcutaneous layer deep to skin • Not part of skin but shares some functions • Mostly adipose tissue that absorbs shock and insulates • Anchors skin to underlying structures: mostly muscles . Cells of the Epidermis • Epidermis consists mostly of keratinized stratified squamous epithelium • Four cell types found in epidermis: 1. Keratinocytes • Produce fibrous keratin (protein that gives ____ its protective properties) • Major cells of epidermis • Tightly connected by desmosomes • Millions slough off every day 2. Melanocytes • Spider-shaped cells located in deepest epidermis • Produce pigment melanin, which is packaged into melanosomes - Melanosomes are transferred to keratinocytes, where they protect nucleus from UV damage 3. Dendritic (Langerhans) cells • Star-shaped macrophages that patrol deep epidermis - Are key activators of immune system 4. Tactile (Merkel) cells • Sensory receptors that sense touch • Epidermis is made up of four or five distinct layers - Thick ____ contains five layers (strata) and is found in high-abrasion areas (hands, feet) - Thin ____ contains only four strata • Five layers of skin 1. Stratum basale 2. Stratum spinosum 3. Stratum granulosum 4. Stratum lucidum (only in thick skin) 5. Stratum corneum 1. Stratum basale (basal layer) - Deepest of all epidermal layers (base layer) - Layer that is firmly attached to dermis - Consists of a single row of stem cells that actively divide (mitotic), producing two daughter cells each time • One daughter cell journeys from basal layer to surface, taking 25-45 days to reach surface - Cell dies as it moves toward surface • Other daughter cell remains in stratum basale as stem cell - Layer also known as stratum germinativum because of active mitosis 2. Stratum spinosum (prickly layer) - Several cell layers thick - Cells contain weblike system of intermediate prekeratin filaments attached to desmosomes • Allows them to resist tension and pulling - Keratinocytes in this layer appear spikey, so they are called prickle cells - Scattered among keratinocytes are abundant melanosomes and dendritic cells 3. Stratum granulosum (granular layer) - Four to six cells thick, but cells are flattened, so layer is thin - Cell appearance changes • Cells flatten, nuclei and organelles disintegrate • Keratinization begins - Cells accumulate keratohyaline granules that help form keratin fibers in upper layers • Cells also accumulate lamellar granules, a water-resistant glycolipid that slows water loss - Cells above this layer die • Too far from dermal capillaries to survive 4. Stratum lucidum (clear layer) - Found only in thick _____ - Consists of thin, translucent band of two to three rows of clear, flat, dead keratinocytes - Lies superficial to the stratum granulosum 5. Stratum corneum (horny layer) - 20-30 rows of flat, anucleated, keratinized dead cells - Accounts for three-quarters of epidermal thickness - Though dead, cells still function to: • Protect deeper cells from the environment • Prevent water loss • Protect from abrasion and penetration • Act as a barrier against biological, chemical, and physical assaults • Cells change by going through apoptosis (controlled cell death) - Dead cells slough off as dandruff and dander - Humans can shed ~50,000 cells every minute . Dermis • Strong, flexible connective tissue • Cells include fibroblasts, macrophages, and occasionally mast cells and white blood cells • Fibers in matrix bind body together - Makes up the "hide" that is used to make leather • Contains nerves, blood vessels, and lymphatic vessels • Contains epidermal hair follicles, oil glands, and sweat glands • Two layers - Papillary - Reticular . Papillary Layer • Superficial layer of areolar connective tissue consisting of loose, interlacing collagen and elastic fibers and blood vessels • Loose fibers allow phagocytes to patrol for microorganisms • Dermal papillae: superficial region of dermis that sends fingerlike projections up into epidermis - Projections contains capillary loops, free nerve endings, and touch receptors (tactile corpuscles, also called Meissner's corpuscles) • In thick _____, dermal papillae lie on top of dermal ridges, which give rise to epidermal ridges - Collectively ridges are called friction ridges • Enhance gripping ability • Contribute to sense of touch • Sweat pores in ridges leave unique fingerprint pattern . Reticular Layer • Makes up ~80% of dermal thickness • Consists of coarse, dense fibrous connective tissue - Many elastic fibers provide stretch-recoil properties - Collagen fibers provide strength and resiliency • Bind water, keeping skin hydrated • Extracellular matrix contains pockets of adipose cells • Cleavage (tension) lines in reticular layer are caused by many collagen fibers running parallel to _____ surface - Externally invisible - Important to surgeons because incisions parallel to cleavage lines heal more readily • Flexure lines of reticular layer are dermal folds at or near joints - Dermis is tightly secured to deeper structures - ______ inability to slide easily for joint movement causes deep creases - Visible on hands, wrists, fingers, soles, toes • Three pigments contribute to ____ color 1. Melanin • Only pigment made in skin; made by melanocytes - Packaged into melanosomes that are sent to keratinocytes to shield DNA from sunlight - Sun exposure stimulates melanin production • Two forms: reddish yellow to brownish black • All humans have same number of keratinocytes, so color differences are due to amount and form of melanin • Freckles and pigmented moles are local accumulations of melanin 2. Carotene • Yellow to orange pigment • Most obvious in palms and soles • Accumulates in stratum corneum and hypodermis • Can be converted to vitamin A for vision and epidermal health 3. Hemoglobin • Pinkish hue of fair skin is due to lower levels of melanin - ____ of Caucasians is more transparent, so color of hemoglobin shows through • _____ is first and foremost a barrier • Its main functions include: - Protection - Body temperature regulation - Cutaneous sensations - Metabolic functions - Blood reservoir - Excretion of wastes . Protection • _____ is exposed to microorganisms, abrasions, temperature extremes, and harmful chemicals • Constitutes three barriers: - Chemical barrier - Physical barrier - Biological barrier • Chemical barrier - _____ secretes many chemicals, such as: • Sweat, which contains antimicrobial proteins • Sebum and defensins, which kill bacteria • Cells also secrete antimicrobial defensin - Acid mantle: low pH of skin retards bacterial multiplication - Melanin provides a chemical barrier against UV radiation damage • Physical barrier - Flat, dead, keratinized cells of stratum corneum, surrounded by glycolipids, block most water and water-soluble substances - Some chemicals have limited penetration of _____ • Lipid-soluble substances • Plant oleoresins (e.g., poison ivy) • Organic solvents (acetone, paint thinner) • Salts of heavy metals (lead, mercury) • Some drugs (nitroglycerin) • Drug agents (enhancers that help carry other drugs across _____) • Biological barriers - Epidermis contains phagocytic cells • Dendritic cells of epidermis engulf foreign antigens (invaders) and present to white blood cells, activating the immune response - Dermis contains macrophages • Macrophages also activate immune system by presenting foreign antigens to white blood cells - DNA can absorb harmful UV radiation, converting it to harmless heat . Body Temperature Regulation • Under normal, resting body temperature, sweat glands produce about 500 ml/day of unnoticeable sweat - Called insensible perspiration • If body temperature rises, dilation of dermal vessels can increase sweat gland activity to produce 12 L (3 gallons) of noticeable sweat - Called sensible perspiration; designed to cool body • Cold external environment - Dermal blood vessels constrict - ______ temperature drops to slow passive heat loss . Cutaneous Sensations • Cutaneous sensory receptors are part of the nervous system - Exteroreceptors respond to stimuli outside body, such as temperature and touch - Free nerve endings sense painful stimuli . Metabolic Functions • _____ can synthesize vitamin D needed for calcium absorption in intestine • Chemicals from keratinocytes can disarm some carcinogens • Keratinocytes can activate some hormones - Example: convert cortisone into hydrocortisone • ______ makes collagenase, which aids in natural turnover of collagen to prevent wrinkles . Blood Resevoir • _____ can hold up to 5% of the body's total blood volume • ______ vessels can be constricted to shunt blood to other organs, such as an exercising muscle . Excretion • _____ can secrete limited amounts of nitrogenous wastes, such as ammonia, urea, and uric acid • Sweating can cause salt and water loss . ____ cancer and Burnes • _____ can develop over 1000 different conditions and ailments • Many internal diseases reveal themselves on skin • Most common disorders are infections • Less common, but more damaging, are: - _____ cancer - Burns • Most _____ tumors are benign (not cancerous) and do not spread (metastasize) • Risk factors - Overexposure to UV radiation - Frequent irritation of _____ • Some ______ lotions contain enzymes that can repair damaged DNA • Three major types of _____ cancer - Basal cell carcinoma - Squamous cell carcinoma - Melanoma • Basal cell carcinoma - Least malignant and most common - Stratum basale cells proliferate and slowly invade dermis and hypodermis - Cured by surgical excision in 99% of cases • Squamous cell carcinoma - Second most common type; can metastasize - Involves keratinocytes of stratum spinosum - Usually is a scaly reddened papule on scalp, ears, lower lip, or hands - Good prognosis if treated by radiation therapy or removed surgically • Melanoma - Cancer of melanocytes; is most dangerous type because it is highly metastatic and resistant to chemotherapy - Treated by wide surgical excision accompanied by immunotherapy - Key to survival is early detection: ABCD rule • A: asymmetry; the two sides of the pigmented area do not match • B: border irregularity; exhibits indentations • C: color; contains several colors (black, brown, tan, sometimes red or blue) • D: diameter; larger than 6 mm (size of pencil eraser) . Burns • Tissue damage caused by heat, electricity, radiation, or certain chemicals - Damage caused by denaturation of proteins, which destroys cells • Immediate threat is dehydration and electrolyte imbalance - Leads to renal shutdown and circulatory shock • To evaluate burns, the Rule of Nines is used - Body is broken into 11 sections, with each section representing 9% of body surface (except genitals, which account for 1%) • Burns can be classified by severity - First-degree • Epidermal damage only - Localized redness, edema (swelling), and pain - Second-degree • Epidermal and upper dermal damage - Blisters appear - First- and second-degree burns are referred to as partial-thickness burns because only the epidermis and upper dermis are involved - Third-degree • Entire thickness of _____ involved (referred to as full-thickness burns) • _____ color turns gray-white, cherry red, or blackened • No edema is seen and area is not painful because nerve endings are destroyed • _____ grafting usually necessary • Burns are considered critical if: - >25% of body has second-degree burns - >10% of body has third-degree burns - Face, hands, or feet bear third-degree burns • Treatment includes: - Debridement (removal) of burned skin - Antibiotics - Temporary covering - _____ grafts

Skin

• Most skin tumors are benign (not cancerous) and do not spread (metastasize) • Risk factors - Overexposure to UV radiation - Frequent irritation of skin • Some skin lotions contain enzymes that can repair damaged DNA • Three major types of ____ _____ - Basal cell carcinoma - Squamous cell carcinoma - Melanoma • Basal cell carcinoma - Least malignant and most common - Stratum basale cells proliferate and slowly invade dermis and hypodermis - Cured by surgical excision in 99% of cases • Squamous cell carcinoma - Second most common type; can metastasize - Involves keratinocytes of stratum spinosum - Usually is a scaly reddened papule on scalp, ears, lower lip, or hands - Good prognosis if treated by radiation therapy or removed surgically • Melanoma - ______ of melanocytes; is most dangerous type because it is highly metastatic and resistant to chemotherapy - Treated by wide surgical excision accompanied by immunotherapy - Key to survival is early detection: ABCD rule • A: asymmetry; the two sides of the pigmented area do not match • B: border irregularity; exhibits indentations • C: color; contains several colors (black, brown, tan, sometimes red or blue) • D: diameter; larger than 6 mm (size of pencil eraser)

Skin Cancer

- ______ ______ tissue: found in walls of hollow organs • Examples: stomach, urinary bladder, and airways - Not striated - Involuntary: cannot be controlled consciously • Can contract on its own without nervous system stimulation

Smooth Muscle

• Found in walls of most hollow organs, except heart - Heart contains cardiac muscle . Microscopic Structure • Spindle-shaped fibers: thin and short compared with skeletal muscle fibers - Only one nucleus, no striations • Lacks connective tissue sheaths - Contains endomysium only • All but smallest blood vessels contain smooth muscle organized into two layers of opposing sheets of fibers - Longitudinal layer: fibers run parallel to long axis of organ • Contraction causes organ to shorten - Circular layer: fibers run around circumference of organ • Contraction causes lumen of organ to constrict • Allows peristalsis: alternating contractions and relaxations of layers mix and squeeze substances through lumen of hollow organs • No neuromuscular junction, as in skeletal muscle • Instead, autonomic nerve fibers innervate smooth muscle - Contain varicosities (bulbous swellings) of nerve fibers - Varicosities store and release neurotransmitters into a wide synaptic cleft referred to as a diffuse junction • Smooth muscle does not contain sarcomeres, myofibrils, or T tubules • SR is less developed than in skeletal muscle - SR does store intracellular Ca2+, but most calcium used for contraction has extracellular origins • Sarcolemma contains pouchlike infoldings called caveolae - Caveolae contain numerous Ca2+ channels that open to allow rapid influx of extracellular Ca2+ • Smooth muscle also differs from skeletal muscle in following ways: - Thick filaments are fewer and have myosin heads along entire length • Ratio of thick to thin filaments (1:13) is much lower than in skeletal muscle (1:2) • Thick filaments have heads along entire length, making smooth muscle as powerful as skeletal muscle - No troponin complex • Does contain tropomyosin, but not troponin • Protein calmodulin binds Ca2+ - Thick and thin filaments arranged diagonally • Myofilaments are spirally arranged, causing smooth muscle to contract in corkscrew manner - Intermediate filament-dense body network • Contain lattice-like arrangement of noncontractile intermediate filaments that resist tension • Dense bodies: proteins that anchor filaments to sarcolemma at regular intervals - Correspond to Z discs of skeletal muscle • During contraction, areas of sarcolemma between dense bodies bulge outward - Make muscle cell look puffy . Contraction of Smooth Muscle • Mechanism of contraction - Slow, synchronized contractions - Cells electrically coupled by gap junctions • Action potentials transmitted from fiber to fiber - Some cells are self-excitatory (depolarize without external stimuli) • Act as pacemakers for sheets of muscle • Rate and intensity of contraction may be modified by neural and chemical stimuli - Contraction in smooth muscle is similar to skeletal muscle contraction in following ways: • Actin and myosin interact by sliding filament mechanism • Final trigger is increased intracellular Ca2+ level • ATP energizes sliding process • Contraction stops when Ca2+ is no longer available - Contraction in smooth muscle is different from skeletal muscle in following ways: • Some Ca2+ still obtained from SR, but mostly comes from extracellular space • Ca2+ binds to calmodulin, not troponin • Activated calmodulin then activates myosin kinase (myosin light chain kinase) • Activated myosin kinase phosphorylates myosin head, activating it - Leads to crossbridge formation with actin - Stopping smooth muscle contraction requires more steps than skeletal muscle • Relaxation requires: - Ca2+ detachment from calmodulin - Active transport of Ca2+ into SR and extracellularly - Dephosphorylation of myosin to inactive myosin • Energy efficiency of smooth muscle contraction - Slower to contract and relax but maintains contraction for prolonged periods with little energy cost • Slower ATPases • Myofilaments may latch together to save energy - Most smooth muscle maintain moderate degree of contraction constantly without fatiguing • Referred to as smooth muscle tone - Makes ATP via aerobic respiration pathways • Regulation of contraction - Controlled by nerves, hormones, or local chemical changes - Neural regulation • Neurotransmitter binding causes either graded (local) potential or action potential - Results in increases in Ca2+ concentration in sarcoplasm - Response depends on neurotransmitter released and type of receptor molecules » One neurotransmitter can have a stimulatory effect on smooth muscle in one organ, but an inhibitory effect in a different organ - Hormones and local chemicals • Some smooth muscle cells have no nerve supply - Depolarize spontaneously or in response to chemical stimuli that bind to G protein-linked receptors - Chemical factors can include hormones, high CO2, pH, low oxygen • Some smooth muscles respond to both neural and chemical stimuli • Special features of smooth muscle contraction - Response to stretch • Stress-relaxation response: responds to stretch only briefly, then adapts to new length - Retains ability to contract on demand - Enables organs such as stomach and bladder to temporarily store contents - Length and tension changes • Can contract when between half and twice its resting length - Allows organ to have huge volume changes without becoming flabby when relaxed • Smooth muscle varies in different organs by: 1. Fiber arrangement and organization 2. Innervation 3. Responsiveness to various stimuli • All smooth muscle is categorized as either: - Unitary - Multiunit • Unitary smooth muscle - Commonly referred to as visceral muscle - Found in all hollow organs except heart - Possess all common characteristics of smooth muscle: • Arranged in opposing (longitudinal and circular) sheets • Innervated by varicosities • Often exhibit spontaneous action potentials • Electrically coupled by gap junctions • Respond to various chemical stimuli • Multiunit smooth muscle - Located in large airways in lungs, large arteries, arrector pili muscles, and iris of eye - Very few gap junctions, and spontaneous depolarization is rare - Similar to skeletal muscle in some features • Consists of independent muscle fibers • Innervated by autonomic nervous system, forming motor units • Graded contractions occur in response to neural stimuli that involve recruitment - Different from skeletal muscle because, like unitary smooth muscle, it is controlled by autonomic nervous system and hormones • All muscle tissues develop from embryonic myoblasts • Multinucleated skeletal muscle cells form by fusion of many myoblasts • Growth factor stimulates clustering of ACh receptors at neuromuscular junctions • Cardiac and smooth muscle myoblasts do not fuse, but develop gap junctions - Cardiac muscle cells start pumping when embryo is 3 weeks old • Regeneration of muscle: - Myoblast-like skeletal muscle satellite cells have limited regenerative ability - Cardiomyocytes can divide at modest rate, but injured heart muscle is mostly replaced by connective tissue - Smooth muscle regenerates throughout life • Cardiac and skeletal muscle can lengthen and thicken in growing child - In adults, leads to hypertrophy • Muscular development in infants reflects neuromuscular coordination - Development occurs head to toe, and proximal to distal • A baby can lift its head before it is able to walk • Peak natural neural control occurs by midadolescence - Athletics and training can continue to improve neuromuscular control • Difference in muscle mass between sexes: - Female skeletal muscle makes up 36% of body mass - Male skeletal muscle makes up 42% of body mass, primarily as a result of testosterone • Males have greater ability to enlarge muscle fibers, also because of testosterone - Body strength per unit muscle mass is the same in both sexes • Aging muscles: - With age, connective tissue increases, and muscle fibers decrease - By age 30, loss of muscle mass (sarcopenia) begins - Regular exercise reverses sarcopenia - Atherosclerosis may block distal arteries, leading to intermittent claudication (limping) and severe pain in leg muscles

Smooth Muscle

• Three pigments contribute to ____ ____ 1. Melanin • Only pigment made in skin; made by melanocytes - Packaged into melanosomes that are sent to keratinocytes to shield DNA from sunlight - Sun exposure stimulates melanin production • Two forms: reddish yellow to brownish black • All humans have same number of keratinocytes, so color differences are due to amount and form of melanin • Freckles and pigmented moles are local accumulations of melanin 2. Carotene • Yellow to orange pigment • Most obvious in palms and soles • Accumulates in stratum corneum and hypodermis • Can be converted to vitamin A for vision and epidermal health 3. Hemoglobin • Pinkish hue of fair skin is due to lower levels of melanin - Skin of Caucasians is more transparent, so color of hemoglobin shows through

Skin Color

What does the integumentary System consist of?

Skin Hair Nails Sweat glands Sebaceous gland

• Fetal: by end of 4th month, ____ of fetus is developed - ______ ______: delicate hairs in 5th and 6th month - ______ _______: sebaceous gland secretion that protects skin of fetus while in watery amniotic fluid

Skin Lanugo coat Vernix caseosa

• Excessive sun exposure damages ____ - Elastic fibers clump, causing skin to become _____ - Can depress immune system and cause alterations in DNA that may lead to _____ _____ - _____ ____destroys folic acid • Necessary for DNA synthesis, so insufficient folic acid is especially dangerous for developing embryos - ______ is increased reaction to sun • Some drugs (e.g., antibiotics, antihistamines) and perfumes cause photosensitivity, leading to skin rashes.

Skin Leathery Skin cancer UV light Photosensitivity

• Skin can develop over 1000 different conditions and ailments • Many internal diseases reveal themselves on skin • Most common disorders are infections • Less common, but more damaging, are: - _____ _____ - ______

Skin cancer Burns

Skeletal Muscle Fibers • Contraction: the activation of cross bridges to generate force • Shortening occurs when tension generated by cross bridges on thin filaments exceeds forces opposing shortening • Contraction ends when cross bridges become inactive • In the relaxed state, thin and thick filaments overlap only slightly at ends of A band • _______ ________ ________ ____ ________ states that during contraction, thin filaments slide past thick filaments, causing actin and myosin to overlap more - Neither thick nor thin filaments change length, just overlap more • When nervous system stimulates muscle fiber, myosin heads are allowed to bind to actin, forming cross bridges, which cause sliding (contraction) process to begin • Cross bridge attachments form and break several times, each time pulling thin filaments a little closer toward center of sarcome in a ratcheting action - Causes shortening of muscle fiber • Z discs are pulled toward M line • I bands shorten • Z discs become closer • H zones disappear • A bands move closer to each other

Sliding Filament Model of Contraction

Factors of Muscle Contraction Velocity and Duration of Contraction Muscle Fiber Type . Low-intensity, endurance activities - Example: maintaining posture

Slow Oxidative Fibers

What three types can skeletal muscle fibers be classified as?

Slow oxidative Fast oxidative Fast glycolytic

Muscles of walls of hollow organs

Smooth

What are the second names of the epithelia tissues?

Squamous Cuboidal Columnar

- Found mainly in walls of hollow organs (other than heart) - Involuntary muscle - Has no visible striations - Spindle-shaped cells with one nucleus Description:Spindle-shaped (elongated) cells with central nuclei; no striations; cells arranged closely to form sheet. Function:Propels substances or objects (foodstuffs, urine, a baby) along internal passageways; involuntary control. Location:Mostly in the walls of hollow organs.

Smooth Muscle Tissue

What do tissues have that regenerate moderately well?

Smooth muscle Dense regular connective

Smooth Muscle Contraction of Smooth Muscle - Response to stretch • Stress-relaxation response: responds to stretch only briefly, then adapts to new length - Retains ability to contract on demand - Enables organs such as stomach and bladder to temporarily store contents - Length and tension changes • Can contract when between half and twice its resting length - Allows organ to have huge volume changes without becoming flabby when relaxed

Special Features of Smooth Muscle Contraction

- Supination and pronation: rotation of radius and ulna • Supination: palms face anteriorly - Radius and ulna are parallel • Pronation: palms face posteriorly - Radius rotates over ulna - Dorsiflexion and plantar flexion of foot • Dorsiflexion: bending foot toward shin • Plantar flexion: pointing toes - Inversion and eversion of foot • Inversion: sole of foot faces medially • Eversion: sole of foot faces laterally - Protraction and retraction: movement in lateral plane • Protraction: mandible juts out • Retraction: mandible is pulled toward neck - Elevation and depression of mandible • Elevation: lifting body part superiorly - Example: shrugging shoulders • Depression: lowering body part - Example: opening jaw - Opposition: movement of thumb • Example: touching thumb to tips of other fingers on same hand or any grasping movement

Special Movements of Synovial Joints

Individual body cells are ______ Each type performs specific functions that maintain _____

Specialized Homeostasis

Made up of a honeycomb of small, needle-like or flat pieces of bone called trabeculae •Open spaces between trabeculae are filled with red or yellow bone marrow

Spongey Bone

- Reinforcing ligaments are stretched or torn - Common sites are ankle, knee, and lumbar region of back - Partial tears repair very slowly because of poor vascularization - Three options if torn completely • Ends of ligaments can be sewn together • Replaced with grafts • Just allow time and immobilization for healing

Sprains

- Second most common type; can metastasize - Involves keratinocytes of stratum spinosum - Usually is a scaly reddened papule on scalp, ears, lower lip, or hands - Good prognosis if treated by radiation therapy or removed surgically

Squamous Carcinoma

To enhance contrast, although artifacts (distortions) detract from what the sample looks like in living tissues Light microscopy uses colored dyes Electron microscopy uses heavy metal coatings

Stained

Regeneration and fibrosis effect permanent repair - The scab detaches - Fibrous tissue matures - Epithelium thickens and begins to resemble adjacent tissue - Results in a fully regenerated epithelium with underlying scar tissue, which may or may not be visible . Regeneration and fibrosis effect permanent repair: •The fibrosed area matures and contracts; the epithelium thickens. •A fully regenerated epithelium with an underlying area of scar tissue results.

Step Three of Tissue Repair

. Also very limited distribution in body . Small amounts found in pharynx, in male urethra, and lining some glandular ducts . Usually occurs at transition areas between two other types of epithelia . Only apical layer is columnar

Stratified Columnar Epithelium

. Quite rare . Found in some sweat and mammary glands . Typically only two cell layers thick

Stratified Cuboidal Epithelium

Epithelia Are two or more layers thick and involved in protection (example: skin)

Stratified Epithelia

. Involve two or more layers of cells . New cells regenerate from below 1. Basal cells divide and migrate toward surface . More durable than simple epithelia because protection is the major role

Stratified Epithelial Tissues

. Most widespread of stratified epithelia . Free surface is squamous, with deeper cuboidal or columnar layers . Located in areas of high wear and tear (example: skin) . Keratinized cells found in skin; nonkeratinized cells are found in moist linings Description: Thick membrane composed of several cell layers; basal cells are cuboidal or columnar and metabolically active; surface cells are flattened (squamous); in the keratinized type, the surface cells are full of keratin and dead; basal cells are active in mitosis and produce the cells of the more superficial layers. Function: Protects underlying tissues in areas subjected to abrasion. Location: Nonkeratinized type forms the moist linings of the esophagus, mouth, and vagina; keratinized variety forms the epidermis of the skin, a dry membrane.

Stratified Squamous Epithelium

- Deepest of all epidermal layers (base layer) - Layer that is firmly attached to dermis - Consists of a single row of stem cells that actively divide (mitotic), producing two daughter cells each time • One daughter cell journeys from basal layer to surface, taking 25-45 days to reach surface - Cell dies as it moves toward surface • Other daughter cell remains in stratum basale as stem cell - Layer also known as stratum germinativum because of active mitosis

Stratum Basale

Basal Layer

Stratum Basale

Horney Layer

Stratum Coreum

- 20-30 rows of flat, anucleated, keratinized dead cells - Accounts for three-quarters of epidermal thickness - Though dead, cells still function to: • Protect deeper cells from the environment • Prevent water loss • Protect from abrasion and penetration • Act as a barrier against biological, chemical, and physical assaults

Stratum Corneum

- Four to six cells thick, but cells are flattened, so layer is thin - Cell appearance changes • Cells flatten, nuclei and organelles disintegrate • Keratinization begins - Cells accumulate keratohyaline granules that help form keratin fibers in upper layers • Cells also accumulate lamellar granules, a water-resistant glycolipid that slows water loss - Cells above this layer die • Too far from dermal capillaries to survive

Stratum Granulosum

Granular Layer

Stratum Granulosum

- Found only in thick skin - Consists of thin, translucent band of two to three rows of clear, flat, dead keratinocytes - Lies superficial to the stratum granulosum

Stratum Lucidum

Clear Layer

Stratum Lucidum

- Several cell layers thick - Cells contain weblike system of intermediate prekeratin filaments attached to desmosomes • Allows them to resist tension and pulling - Keratinocytes in this layer appear spikey, so they are called prickle cells - Scattered among keratinocytes are abundant melanosomes and dendritic cells

Stratum Spinosum

Prickly Layer

Stratum Spinosum

What are the 5 layers of the epidermis?

Stratum basale Stratum spinosum Stratum granulosum Stratum lucidum Stratum corneum

Smooth Muscle Contraction of Smooth Muscle Special Features of Smooth Muscle Contraction Response to Stretch . Responds to stretch only briefly, then adapts to new length - Retains ability to contract on demand - Enables organs such as stomach and bladder to temporarily store contents

Stress Relaxation

• Extreme stretching of skin can cause dermal tears, leaving silvery white scars called _____ - Also known as "stretch marks" • Acute, short-term traumas to skin can cause _____, fluid-filled pockets that separate epidermal and dermal layers

Striae Blisters

. Stripes formed from repeating series of dark and light bands along length of each myofibril - A bands: dark regions • H zone: lighter region in middle of dark A band - M line: line of protein (myomesin) that bisects H zone vertically - I bands: lighter regions • Z disc (line): coin-shaped sheet of proteins on midline of light I band

Striations

What features do myofibrils contain?

Striations Sarcomeres Myofilaments Molecular composition of myofilaments

What are the two classifications of joints?

Structural

. Three types based on what material binds the joints and whether a cavity is present • Fibrous • Cartilaginous • Synovial

Structural Functional

Dislocation . Partial dislocation of a joint

Subluxation

What are the four rotator cuffs that encircle the shoulder joint?

Subscapularis Supraspinatus Infraspinatus Teres minor

Whole Muscle Contractions Graded Muscle Response Changing Frequency of Stimulation . Stimulus not strong enough, so no contractions seen

Subthreshold Stimulus

What are the types of stimulus involved in recruitment for muscles?

Subthreshold Threshold Maximal

• Infancy to adulthood: skin thickens and accumulates more ______ ______, ______ and _____ ______ activity increases, leading to acne - Optimal appearance during 20s and 30s - After age 30, effects of cumulative environmental assaults start to show - Scaling and dermatitis become more common

Sucutaneous fat Sweat Sebaceous gland

Toward or at the body surface External

Superficial

Cranial Toward the head end or upper part of a structure or a body.

Superior

. Rotation of radius and ulna • ________: palms face anteriorly - Radius and ulna are parallel • __________: palms face posteriorly - Radius rotates over ulna

Supination and Pronation

What are the seven functions of bones?

Suppor Protection Movement Mineral and growth factor storage Blood cell formation Fat storage Hormone production

Support, insulate, and protect neurons

Supporting Cells

• Rigid, interlocking joints of skull • Allow for growth during youth - Contain short connective tissue fibers that allow for expansion • In middle age, sutures ossify and fuse - Immovable joints join skull into one unit that protects brain - Closed, immovable sutures referred to as synostoses

Sutures

What are the three types of fibrous joints?

Sutures Syndesmoses Gomphoses

• Also called sudoriferous glands • All skin surfaces except nipples and parts of external genitalia contain ______ ______ - About 3 million per person • Two main types - Eccrine (merocrine) sweat glands - Apocrine sweat glands • Contain myoepithelial cells - Contract upon nervous system stimulation to force ______ into ducts . Eccrine Glands • Most numerous type • Abundant on palms, soles, and forehead • Ducts connect to pores • Function in thermoregulation - Regulated by sympathetic nervous system • Their secretion is _____ - 99% water, salts, vitamin C, antibodies, dermcidin (microbe-killing peptide), metabolic wastes . Appocrine Glands • Confined to axillary and anogenital areas • Secrete viscous milky or yellowish ______ that contains fatty substances and proteins - Bacteria break down ______, leading to body odor • Larger than eccrine ______ ______ with ducts emptying into hair follicles • Begin functioning at puberty - Function unknown but may act as sexual scent gland • Modified apocrine glands - Ceruminous glands: lining of external ear canal; secrete cerumen (earwax) - Mammary glands: secrete milk

Sweat Glands

• Fibrocartilage unites bone in ________ joint - Hyaline cartilage also present as articular cartilage on bony surfaces • _________ are strong, amphiarthrotic (slightly movable) joints • Examples - Intervertebral joints - Pubic symphysis

Symphyses

Muscle Fiber Contraction The Nerve Stimulus and Events at the Neuromuscular Junction . Gel-filled space

Synaptic Cleft

Immovable joints

Synarthroses

What are the three types of movements in joints?

Synarthroses Amphiarthroses Diarthroses

• Bar or plate of hyaline cartilage unites bones • Almost all are synarthrotic (immovable) • Examples - Temporary epiphyseal plate joints • Become synostoses after plate closure - Cartilage of 1st rib with manubrium of sternum

Synchondroses

What are the two cartilaginous joints?

Synchondroses Symphyses

• Bones connected by ligaments, bands of fibrous tissue • Fiber length varies, so movement varies - Short fibers offer little to no movement • Example: inferior tibiofibular joint - Longer fibers offer a larger amount of movement • Example: interosseous membrane connecting radius and ulna

Syndesmoses

What cavity is not exposed to the environment? Joint Cavities

Synovial Cavities

. Viscous, slippery filtrate of plasma and hyaluronic acid • Lubricates and nourishes articular cartilage • Contains phagocytic cells to remove microbes and debris

Synovial Fluid

• Bones separated by fluid-filled joint cavity • All are diarthrotic (freely movable) • Include almost all limb joints • Characteristics of _______ _______ - Have six general features - Have bursae and tendon sheaths associated with them - Stability is influenced by three factors - Allow several types of movements - Classified into six different types • _______ _______ have six general features: 1. Articular cartilage: consists of hyaline cartilage covering ends of bones • Prevents crushing of bone ends 2. Joint (________) cavity: small, fluid-filled potential space that is unique to ________ ______ 3. Articular (joint) capsule: two layers thick • External fibrous layer: dense irregular connective tissue • Inner ________ membrane: loose connective tissue that makes _______ fluid 4. ________ fluid: viscous, slippery filtrate of plasma and hyaluronic acid • Lubricates and nourishes articular cartilage • Contains phagocytic cells to remove microbes and debris 5. Different types of reinforcing ligaments • Capsular: thickened part of fibrous layer • Extracapsular: outside the capsule • Intracapsular: deep to capsule; covered by _______ membrane 6. Nerves and blood vessels • Nerves detect pain; monitor joint position and stretch • Capillary beds supply filtrate for _______ fluid • Other features of some ______ _______: - Fatty pads • For cushioning between fibrous layer of capsule and _________ membrane or bone - Articular discs (menisci) • Fibrocartilage separates articular surfaces to improve "fit" of bone ends, stabilize joint, and reduce wear and tear • Bags of _______ fluid that act as lubricating "ball bearing" - Not strictly part of synovial joints, but closely associated • Bursae: reduce friction where ligaments, muscles, skin, tendons, or bones rub together • Tendon sheaths: elongated bursae wrapped completely around tendons subjected to friction • Three factors determine stability of joints to prevent dislocations: 1. Shape of articular surface (minor role) • Shallow surfaces less stable than ball-and-socket 2. Ligament number and location (limited role) • The more ligaments, the stronger the joint 3. Muscle tone keeps tendons taut as they cross joints (most important) • Extremely important in reinforcing shoulder and knee joints and arches of the foot • All muscles attach to bone or connective tissue at no fewer than two points - Origin: attachment to immovable bone - Insertion: attachment to movable bone • Muscle contraction causes insertion to move toward origin • Movements occur along transverse, frontal, or sagittal planes • Range of motion allowed by _______ ________ - Nonaxial: slipping movements only - Uniaxial: movement in one plane - Biaxial: movement in two planes - Multiaxial: movement in or around all three planes • Three general types of movements - Gliding - Angular movements - Rotation • Gliding movements - One flat bone surface glides or slips over another similar surface - Examples • Intercarpal joints • Intertarsal joints • Between articular processes of vertebrae • Angular movements - Increase or decrease angle between two bones - Movement along sagittal plane - Angular movements include: • Flexion: decreases the angle of the joint • Extension: increases the angle of the joint - Hyperextension: movement beyond the anatomical position - Abduction: movement along frontal plane, away from the midline - Adduction: movement along frontal plane, toward the midline - Circumduction • Involves flexion, abduction, extension, and adduction of limb • Limb describes cone in space • Rotation: turning of bone around its own long axis, toward midline or away from it - Medial: rotation toward midline - Lateral: rotation away from midline - Examples • Rotation between C1 and C2 vertebrae • Rotation of humerus and femur • Special movements - Supination and pronation: rotation of radius and ulna • Supination: palms face anteriorly - Radius and ulna are parallel • Pronation: palms face posteriorly - Radius rotates over ulna - Dorsiflexion and plantar flexion of foot • Dorsiflexion: bending foot toward shin • Plantar flexion: pointing toes - Inversion and eversion of foot • Inversion: sole of foot faces medially • Eversion: sole of foot faces laterally - Protraction and retraction: movement in lateral plane • Protraction: mandible juts out • Retraction: mandible is pulled toward neck - Elevation and depression of mandible • Elevation: lifting body part superiorly - Example: shrugging shoulders • Depression: lowering body part - Example: opening jaw - Opposition: movement of thumb • Example: touching thumb to tips of other fingers on same hand or any grasping movement • There are six different types of _______ _______ - Categories are based on shape of articular surface, as well as movement joint is capable of • Plane • Hinge • Pivot • Condylar • Saddle • Ball-and-socket • _______ ________ are diverse • All have general features, but some also have unique structural features, abilities, and weaknesses • Five main synovial joints - Knee - Shoulder - Elbow - Hip - Jaw . Knee • Largest, most complex joint of body • Consists of three joints surrounded by single cavity 1. Femoropatellar joint • Plane joint • Allows gliding motion during knee flexion 2. Lateral joint and 3. Medial joint • Lateral and medial joints together are called tibiofemoral joint • Joint between femoral condyles and lateral and medial menisci of tibia • Hinge joint that allows flexion, extension, and some rotation when knee partly flexed • Joint capsule is thin and absent anteriorly • Anteriorly, quadriceps tendon gives rise to three broad ligaments that run from patella to tibia - Medial and lateral patellar retinacula that flank the patellar ligament • Doctors tap patellar ligament to test knee-jerk reflex • At least 12 bursae associated with knee joint • Capsular, extracapsular, or intracapsular ligaments act to stabilize knee joint • Capsular and extracapsular ligaments help prevent hyperextension of knee - Fibular and tibial collateral ligaments: prevent rotation when knee is extended - Oblique popliteal ligament: stabilizes posterior knee joint - Arcuate popliteal ligament: reinforces joint capsule posteriorly • Intracapsular ligaments reside within capsule, but outside ______ ______ • Help to prevent anterior-posterior displacement - Anterior cruciate ligament (ACL) • Attaches to anterior tibia • Prevents forward sliding of tibia and stops hyperextension of knee - Posterior cruciate ligament • Attaches to posterior tibia • Prevents backward sliding of tibia and forward sliding of femur • Knee absorbs great amount of vertical force; however, it is vulnerable to horizontal blows - Common knee injuries involved the 3 C's: • Collateral ligaments • Cruciate ligaments • Cartilages (menisci) - Lateral blows to extended knee can result in tears in tibial collateral ligament, medial meniscus, and anterior cruciate ligament - Injuries affecting just ACL are common in runners who change direction, twisting ACL . Shoulder • Most freely moving joint in body • Stability is sacrificed for freedom of movement • Ball-and-socket joint - Large, hemispherical head of humerus fits in small, shallow glenoid cavity of scapula • Like a golf ball on a tee • Articular capsule enclosing cavity is also thin and loose - Contributes to freedom of movement • Glenoid labrum: fibrocartilaginous rim around glenoid cavity - Helps to add depth to shallow cavity - Cavity still only holds one-third of head of humerus • Reinforcing ligaments - Primarily on anterior aspect - Coracohumeral ligament • Helps support weight of upper limb - Three glenohumeral ligaments • Strengthen anterior capsule, but are weak support • Reinforcing muscle tendons contribute most to joint stability - Tendon of long head of biceps brachii muscle is "superstabilizer" • Travels through intertubercular sulcus • Secures humerus to glenoid cavity - Four rotator cuff tendons encircle the shoulder joint • Subscapularis • Supraspinatus • Infraspinatus • Teres minor . Elbow Joint • Humerus articulates with radius and ulna • Hinge joint formed primarily from trochlear notch of ulna articulating with trochlea of humerus - Allows for flexion and extension only • Anular ligament surrounds head of radius • Two capsular ligaments restrict side-to-side movement - Ulnar collateral ligament - Radial collateral ligament . Hip Joint • Ball-and-socket joint • Large, spherical head of the femur articulates with deep cup-shaped acetabulum • Good range of motion, but limited by the deep socket - Acetabular labrum: rim of fibrocartilage that enhances depth of socket (hip dislocations are rare) • Reinforcing ligaments include: - Iliofemoral ligament - Pubofemoral ligament - Ischiofemoral ligament - Ligament of head of femur (ligamentum teres) • Slack during most hip movements, so not important in stabilizing • Does contain artery that supplies head of femur • Greatest stability comes from deep ball-and-socket joint . Jaw Joint • Jaw joint is a modified hinge joint • Mandibular condyle articulates with temporal bone - Posterior temporal bone forms mandibular fossa, while anterior portion forms articular tubercle • Articular capsule thickens into strong lateral ligament • Two types of movement - Hinge: depression and elevation of mandible - Gliding: side-to-side (lateral excursion) grinding of teeth • Most easily dislocated joint in the body • Dislocation of TMJ is most common because of shallow socket of joint • Almost always dislocates anteriorly, causing mouth to remain open - To realign, physician must push mandible back into place • Symptoms: ear and face pain, tender muscles, popping sounds when opening mouth, joint stiffness • Usually caused by grinding teeth, but can also be due to jaw trauma or poor occlusion of teeth - Treatment for grinding teeth includes bite plate - Relaxing jaw muscles helps

Synovial Joints

Looks at just one system (cardiovascular, nervous, muscular, etc.)

System Anatomy

Skeletal Muscle Fiber - Tube formed by protrusion of sarcolemma deep into cell interior • Increase muscle fiber's surface area greatly • Lumen continuous with extracellular space • Allow electrical nerve transmissions to reach deep into interior of each muscle fiber - Tubules penetrate cell's interior at each A-I band junction between terminal cisterns • Triad: area formed from terminal cistern of one sarcomere,______ , and terminal cistern of neighboring sarcomere

T Tubule

- Tube formed by protrusion of sarcolemma deep into cell interior • Increase muscle fiber's surface area greatly • Lumen continuous with extracellular space • Allow electrical nerve transmissions to reach deep into interior of each muscle fiber - Tubules penetrate cell's interior at each A-I band junction between terminal cisterns • Triad: area formed from terminal cistern of one sarcomere, ________, and terminal cistern of neighboring sarcomere

T Tubules

• Sensory receptors that sense touch

Tactile

Whole Muscle Contractions Graded Muscle Response Changing Frequency of Stimulation . Stimulus is strong enough to cause first observable contraction

Threshold Stimulus

What are the lateral contacts of epithelial tissue?

Tight junctions Desmosomes

Groups of similar cells

Tissue Leve

• When the body's barriers are compromised, the inflammatory and immune responses are activated • _____ starts very quickly • ______ is the function of the inflammatory process • _____ can occur in two major ways: - Regeneration: same kind of tissue replaces destroyed tissue, so original function is restored - Fibrosis: connective tissue replaces destroyed tissue, and original function lost • Step 1: Inflammation sets stage - Release of inflammatory chemicals causes: • Dilation of blood vessels • Increase in blood vessel permeability - Clotting of blood occurs • Severed blood vessels bleed. • Inflammatory chemicals are released by injured tissue cells, mast cells, and others. • Local blood vessels become more permeable, allowing white blood cells, fluid, clotting proteins, and other plasma proteins to seep into the injured area. • Clotting occurs; surface exposed to air dries and forms a scab. • Step 2: Organization restores blood supply - Organization begins as the blood clot is replaced with granulation tissue (new capillary- enriched tissue) - Epithelium begins to regenerate - Fibroblasts produce collagen fibers to bridge the gap until regeneration is complete - Any debris in area is phagocytized • Step 3: Regeneration and fibrosis effect permanent repair - The scab detaches - Fibrous tissue matures - Epithelium thickens and begins to resemble adjacent tissue - Results in a fully regenerated epithelium with underlying scar tissue, which may or may not be visible

Tissue Repair

Groups of cells similar in structure that perform common or related function

Tissues

. Forms lining of hollow urinary organs 1. Found in bladder, ureters, and urethra . Basal layer cells are cuboidal or columnar . Ability of cells to change shape when stretched allows for increased flow of urine and, in the case of bladder, more storage space Description: Resembles both stratified squamous and stratified cuboidal; basal cells cuboidal or columnar; surface cells dome shaped or squamouslike, depending on degree of organ stretch. Function: Stretches readily, permits stored urine to distend urinary organ. Location: Lines the ureters, bladder, and part of the urethra

Transitional Epithelium

Horizontal -Divides body horizontally (90° to vertical plane) into superior and inferior parts (top and bottom) -Produces a cross section

Transverse Plane

Whereas the pelvic bones provide limited protection to the pelvic cavity, the walls of abdominal cavity are formed by muscle only, so organs in this area are most vulnerable to _____

Trauma

Skeletal Muscle Fiber Sarcolema Reticulum and T Tubules . Area formed from terminal cistern of one sarcomere, T tubule, and terminal cistern of neighboring sarcomere - T tubule contains integral membrane proteins that protrude into intermembrane space (space between tubule and muscle fiber sarcolemma) • Tubule proteins act as voltage sensors that change shape in response to an electrical current - SR cistern membranes also have integral membrane proteins that protrude into intermembrane space • SR integral proteins control opening of calcium channels in SR cisterns - When an electrical impulse passes by, ___ _____ proteins change shape, causing _____ proteins to change shape, causing release of calcium into cytoplasm

Triad

Skeletal Muscle Fibers Myofibrils Myofilaments . Regulatory proteins bound to actin

Tropomyosin Troponin

Smooth Muscle Microscopic Structure . Bulbous swellings . Store and release neurotransmitters into a wide synaptic cleft referred to as a diffuse junction

Varicosities

Pale, fine body hair of children and adult females

Vellus Hair

Factors of Muscle Contraction • How fast a muscle contracts and how long it can stay contracted is influenced by: - Muscle fiber type - Load - Recruitment • Muscle fiber type - Classified according to two characteristics 1. Speed of contraction - slow or fast fibers according to: - Speed at which myosin ATPases split ATP - Pattern of electrical activity of motor neurons 2. Metabolic pathways used for ATP synthesis - Oxidative fibers: use aerobic pathways - Glycolytic fibers: use anaerobic glycolysis - Based on these two criteria, skeletal muscle fibers can be classified into three types: • Slow oxidative fibers, fast oxidative fibers, or fast glycolytic fibers - Most muscles contain mixture of fiber types, resulting in a range of contractile speed and fatigue resistance • All fibers in one motor unit are the same type • Genetics dictate individual's percentage of each - Different muscle types are better suited for different jobs • Slow oxidative fibers: low-intensity, endurance activities - Example: maintaining posture • Fast oxidative fibers: medium-intensity activities - Example: sprinting or walking • Fast glycolytic fibers: short-term intense or powerful movements - Example: hitting a baseball • Load and recruitment - Load: muscles contract fastest when no load is added • The greater the load, the shorter the duration of contraction • The greater the load, the slower the contraction - Recruitment: the more motor units contracting, the faster and more prolonged the contraction

Velocity and Duration of Contraction

•Houses the internal organs (collectively called viscera) •Two subdivisions, which are separated by the diaphragm -Thoracic cavity -Abdominopelvic cavity

Ventral Body Cavity

•Thoracic cavity -Two pleural cavities •Each cavity surrounds one lung -Mediastinum •Contains pericardial cavity •Surrounds other thoracic organs, such as esophagus, trachea, etc. -Pericardial cavity •Encloses heart •Abdominopelvic cavity -Abdominal cavity •Contains stomach, intestines, spleen, and liver -Pelvic cavity •Contains urinary bladder, reproductive organs, and rectum-Serosa (also called serous membrane) •Thin, double-layered membranes that cover surfaces in ventral body cavity -Parietal serosa lines internal body cavity walls -Visceral serosa covers internal organs (viscera) •Double layers are separated by slit-like cavity filled with serous fluid •Fluid secreted by both layers of membrane •Named for specific cavity and organs that they are associated with -Pericardium •Heart -Pleurae •Lungs -Peritoneum •Abdominopelvic cavity •Abdominopelvic quadrants and regions -Quadrants are divisions used primarily by medical personnel •Abdominopelvic region is sectioned into quarters -Right upper quadrant (RUQ) -Left upper quadrant (LUQ) -Right lower quadrant (RLQ) -Left lower quadrant (LLQ) • Abdominopelvic quadrants and regions -Nine divisions called regions, resembling a tic-tac-toe grid, are used primarily by anatomists •Right hypochondriac region •Epigastric region •Left hypochondriac region •Right lumbar region •Umbilical region •Left lumber region •Right Iliac (inguinal) region •Hypogastric region •Left iliac (inguinal) region

Ventral Body Cavity

Encases spinal cord

Vertebral Cavity

Covers internal organs

Visceral Serosa

- Most abundant chemical in body; provides the watery environment needed for chemical reactions • Also is fluid base for secretions and excretions

Water

Whole Muscle Contraction Graded Muscle Response Changing Frequency of Stimulation . Results if two stimuli are received by a muscle in rapid succession • Muscle fibers do not have time to completely relax between stimuli, so twitches increase in force with each stimulus • Additional Ca2+ that is released with second stimulus stimulates more shortening • Produces smooth, continuous contractions that add up (summation) • Further increase in stimulus frequency causes muscle to progress to sustained, quivering contraction referred to as unfused (incomplete) tetanus

Wave Summation

Connective Tissue • Neutrophils, eosinophils, lymphocytes • Tissue response to injury

White Blood Cells

• _______ are blocked sebaceous glands - If secretion oxidizes, whitehead becomes a blackhead • ______ is usually an infectious inflammation of the sebaceous glands, resulting in pimples (pustules) • Overactive sebaceous glands in infants can lead to ______, known as "cradle cap" - Begins as pink, raised lesions on scalp that turn yellow/brown and flake of

Whiteheads Acne Seborrhea

• Same principles apply to contraction of both single fibers and whole muscles • Contraction produces muscle tension, the force exerted on load or object to be moved • Contraction may/may not shorten muscle - Isometric contraction: no shortening; muscle tension increases but does not exceed load - Isotonic contraction: muscle shortens because muscle tension exceeds load • Force and duration of contraction vary in response to stimuli of different frequencies and intensities • Each muscle is served by at least one motor nerve - Motor nerve contains axons of up to hundreds of motor neurons - Axons branch into terminals, each of which forms NMJ with single muscle fiber • Motor unit is the nerve-muscle functional unit • Motor unit consists of the motor neuron and all muscle fibers (four to several hundred) it supplies - Smaller the fiber number, the greater the fine control • Muscle fibers from a motor unit are spread throughout the whole muscle, so stimulation of a single motor unit causes only weak contraction of entire muscle • Muscle twitch: simplest contraction resulting from a muscle fiber's response to a single action potential from motor neuron - Muscle fiber contracts quickly, then relaxes • Twitch can be observed and recorded as a myogram - Tracing: line recording contraction activity • Three phases of muscle twitch - Latent period: events of excitation-contraction coupling • No muscle tension seen - Period of contraction: cross bridge formation • Tension increases - Period of relaxation: Ca2+ reentry into SR • Tension declines to zero • Muscle contracts faster than it relaxes • Differences in strength and duration of twitches are due to variations in metabolic properties and enzymes between muscles - Example: eye muscles contraction are rapid and brief, whereas larger, fleshy muscles (calf muscles) contract more slowly and hold it longer • Normal muscle contraction is relatively smooth, and strength varies with needs - A muscle twitch is seen only in lab setting or with neuromuscular problems, but not in normal muscle • Graded muscle responses vary strength of contraction for different demands - Required for proper control of skeletal movement • Responses are graded by: - Changing frequency of stimulation - Changing strength of stimulation • Muscle response to changes in stimulus frequency - Single stimulus results in single contractile response (i.e., muscle twitch) - Wave (temporal) summation results if two stimuli are received by a muscle in rapid succession • Muscle fibers do not have time to completely relax between stimuli, so twitches increase in force with each stimulus • Additional Ca2+ that is released with second stimulus stimulates more shortening • Produces smooth, continuous contractions that add up (summation) • Further increase in stimulus frequency causes muscle to progress to sustained, quivering contraction referred to as unfused (incomplete) tetanus - If stimuli frequency increases, muscle tension reaches maximum • Referred to as fused (complete) tetanus because contractions "fuse" into one smooth sustained contraction plateau • Prolonged muscle contractions lead to muscle fatigue - Recruitment (or multiple motor unit summation): stimulus is sent to more muscle fibers, leading to more precise control - Types of stimulus involved in recruitment: • Subthreshold stimulus: stimulus not strong enough, so no contractions seen • Threshold stimulus: stimulus is strong enough to cause first observable contraction • Maximal stimulus: strongest stimulus that increases maximum contractile force - All motor units have been recruited - Recruitment works on size principle • Motor units with smallest muscle fibers are recruited first • Motor units with larger and larger fibers are recruited as stimulus intensity increases • Largest motor units are activated only for most powerful contractions • Motor units in muscle usually contract asynchronously - Some fibers contract while others rest - Helps prevent fatigue . Muscle Tone • Constant, slightly contracted state of all muscles • Due to spinal reflexes - Groups of motor units are alternately activated in response to input from stretch receptors in muscles • Keeps muscles firm, healthy, and ready to respond • Isotonic contractions: muscle changes in length and moves load - Isotonic contractions can be either concentric or eccentric: • Concentric contractions: muscle shortens and does work - Example: biceps contract to pick up a book • Eccentric contractions: muscle lengthens and generates force - Example: laying a book down causes biceps to lengthen while generating a force • Isometric contractions - Load is greater than the maximum tension muscle can generate, so muscle neither shortens nor lengthens • Electrochemical and mechanical events are same in isotonic or isometric contractions, but results are different - In isotonic contractions, actin filaments shorten and cause movement - In isometric contractions, cross bridges generate force, but actin filaments do not shorten • Myosin heads "spin their wheels" on same actin- binding site

Whole Muscle Contraction

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