Anatomy Test II- Ch 5-9
Outline and discuss the 4 curvatures of the spine.
1. Cervical Curve- 7 vertebrae 2. Thoracic Curve- 12 vertebrae 3. Lumbar Curve- 5 vertebrae 4. Sacral Curve- formed by 5 fused sacral vertebrae. With Coccyx.
Tendon
: a white fibrous cord of dense regular connective tissue that attaches muscle to bone
Rickets
A softening and weakening of bones in children, usually due to inadequate vitamin D, also called osteomalacia
Anatomy of osteon
A structural unit of compact bone consisting of a central canal surrounded by concentric cylindrical lamellae of matrix.
Outline and discuss the three different types of muscles. Gives examples and discuss the functions of each.
- Skeletal Location: skeletal system Function: moves bones Appearance: multinucleated and striated Control: voluntary Example: biceps - Cardiac Location: heart Function: pump blood Appearance: one nucleus, striated, **intercalated discs** Control: involuntary Example: heart - Smooth Location: various organs Function: various functions (example: peristalsis) Appearance: one nucleus, no striations Control: involuntary Example: GI Tract
Incomplete tetanus:
- muscle never relaxes completely. Here stimulation is rapid and action potentials arrive so frequently that only some relaxation is possible.
Outline and discuss the steps in the sliding filament theory.
Myosin pulls on actin causing the thin filament to move inward. The z discs move towards each other and the sarcomere shortens. Calcium is released from the terminal cisternae. Calcium binds to troponin, sliding tropomyosin off actin so myosin can attach. The myosin head forms a crossbridge and slides actin towards the H zone. Which is the powerstroke. (requiring ATP)
Twitch
a brief, contractile response of a skeletal muscle elicited by a single maximal volley of impulses in the neurons supplying it.
Sarcomeres
a contractile unit in a striated muscle fiber (cell) extending from one Z disc to the next Z disc
Fissure
a groove, fold, or slit that may be normal or abnormal
Creatine Phosphate:
a high energy phosphate; acts as a reservoir of phosphate to donate to ADP; stored in muscles along edges of I-band; consumed in meat or synthesized in liver, kidneys and pancreas
Articulation
a joint; a point of contact between bones, cartilage and bones, or teeth and bones
Osteocyte
a mature bone cell that maintains the daily activities of bone tissue
Synergist
a muscle that assists the prime mover by reducing undesired action or unnecessary movement
Fixator
a muscle that stabilizes the origin of the prime mover so that the prime mover can act more efficiently.
Acetylcholine
a neurotransmitter liberated by many peripheral nervous system neurons and some central nervous system neurons. It is excitatory at neuromuscular junctions but inhibitory at some other synapses
Tropomyosin
a protein of muscle that forms a complex with troponin regulating the interaction of actin and myosin in muscle contraction.
Bursa
a sac or pouch of synovial fluid located at friction points, especially around joints
process
any projection or bump
Red/slow skeletal muscle fibers
are aerobic fibers and have plenty of myoglobin. form the "endurance" muscles. are capable of prolonged contractions, but only at a slower pace.
Luxation
bone totally displaced from the joint
Hyperextension
continuation of extension beyond the anatomical position, as in bending the head backward
Epimysium
fibrous connective tissue around muscles
What is a synovial joint and what stabilizes some joints
have a small synovial cavity between the two bones that permits a greater amount of movement than fibrous or cartilaginous joints. Majority of the joints in the human body examples:shoulder, elbow, hip, and knee joints.
Pennate
having a structure like that of a feather especially : being a muscle in which fibers extend obliquely from either side of a central tendon
Osteon
he basic unit of structure in adult compact bone, consisting of a central (haversian) canal with its concentrically arranged lamellae, lacunae, osteocytes, and canaliculi. Also called a haversian system
Calcium
helps in contraction of muscles, maintaining proper excitability of nerves, secretion process of neurotransmitters, clotting of blood Suture: an immovable fibrous joint that joins skull bones
Muscle Fatigue:
inability of a muscle to maintain its strength of contraction or tension; may be related to insufficient oxygen, depletion of glycogen, and/or lactic acid buildup
Endomysium
invagination of the perimysium separating each individual muscle fiber (cell)
How is bone remodeled?
lifelong process where mature bone tissue is removed from the skeleton (a process called bone resorption) and new bone tissue is formed (a process called ossification or new bone formation). Osteoclasts send a message out Osteoclasts attach to the bone matrix. They release enzymes/acids approx 2 wks Secrete bone growth factors Osteoclasts die (apoptosis) Regulated by estrogen Creates a cavity Growth factors stimulate osteoblast formation. Lines the cavity Secretes matrix & some will turn into osteocytes Damage is repaired Increase in density for about 3 yrs
Opposition
movement of thumb at the carpometacarpal joint in which the thumb moves across the palm to touch the tips of the fingers on the same hand
Thick Filament
myosin; 6 polypeptide chain, 400 myosin molecules
Explain how bone grows away from the primary ossification center and the effect of the sex hormones on bone growth and growth during development, childhood and as an adult.
primary ossification center- region, deep in the periosteal collar, where bone development starts during endochondral ossification
Complete tetanus:
relaxation phase is eliminated. Action potentials are coming constantly Calcium is never taken back to the TC/SR Maximum tension is reached Sustained contraction
The functions of the skeletal system.
supports the body facilitates movement protects internal organs produces blood cells stores and releases minerals and fat
Identify and discuss the three functional categories of movement.
synarthrosis - permits little or no mobility. Most synarthrosis joints are fibrous joints (e.g., skull sutures). amphiarthrosis - permits slight mobility. synovial joint (also known as a diarthrosis) - freely movable.
Insertion
the attachment of a muscle tendon to a movable bone or the end opposite the origin
Origin
the attachment of a muscle tendon to a stationary bone or the end opposite the insertion
Sarcolemma
the cell membrane if a muscle fiber (cell), especially of a skeletal muscle fiber
Myosin
the contractile protein that makes up the thick filaments of muscle fibers
Cross Bridge
the globular head of a myosin molecule that projects from a myosin filament in muscle and in the sliding filament hypothesis of muscle contraction is held to attach temporarily to an adjacent actin filament and draw it into the A band of a sarcomere between the myosin filaments.
Prime Mover:
the muscle directly responsible for producing a desired motion. Also called an agonist
Medullary Cavity
the space within the diaphysis of a bone that contains yellow bone marrow. Also called the marrow cavity
Myofibril
threadlike structures extending longitudinally through a muscle fiber (cell) consisting mainly of thick filaments (myosin) and thin filaments (actin, troponin, and tropomyosin)
Classify according to structure and function all joints of the skeleton
Based on Structure: Fibrous - Sutures: dense fibrous connective tissue (example: sutures) -Syndesmosis: more dense fibrous connective tissue than a suture (Example: Gomphosis) -Interosseous membrane: a broad sheet of dense fibrous Connective Tissue (Example: Between radius and ulna) Cartilaginous -Synchondrosis - hyaline cartilage; no movement (Example: Rib 1 - sternum, epiphyseal plate) -Symphysis - fibrocartilage; some movement (Example: Pubic symphysis) Synovial: Articular cartilage on ends of long bones and a synovial cavity between articulating bones surrounded by accessory ligaments; freely moveable (GHCASP,BS) Gliding/Planar: carpal bones (Between flat bones) Hinge: elbow, ankle, knee Condylar: metacarpals to phalanges Saddle: thumb joint Pivot: atlas and axis Ball and Socket: hip, shoulder Based on Function -Synarthroses: allows no movement Example: Suture, gomphosis -Amphiarthroses: Allows little movement Example: pubic symphysis, intervertebral discs -Diarthroses: freely moveable Examples: Hip, knee, shoulder, elbow
Outline and discuss the components of bone matrix. Also identify the organic and inorganic components.
Bones consist of living cells embedded in a mineralized organic matrix. This matrix consists of organic components, mainly type I collagen - "organic" referring to materials produced as a result of the human body - and inorganic components, primarily hydroxyapatite and other salts of calcium and phosphate. Organic-osteoid Inorganic-salt crystals that are primarily calcium phosphate
Outline and discuss the features of a long bone.
Long bones are longer than they are wide and have a shaft and two ends. The diaphysis, or central shaft, contains bone marrow in a marrow cavity. The rounded ends, the epiphyses, are covered with articular cartilage and are filled with red bone marrow, which produces blood cells. Most of the limb bones are long bones—for example, the femur, tibia, ulna, and radius.
Outline and discuss the four steps of intramembranous ossification.
Development of ossification center: osteoblasts secrete organic extracellular matrix. Calcification: calcium and other mineral salts are deposited and extracellular matrix calcified (hardens). Formation of trabeculae: extracellular matrix develops into trabeculae that fuse to form spongy bone. Development of the periosteum: mesenchyme at the periphery of the bone develops into periosteum.
Red/fast skeletal muscle fiber
Fast-contracting muscle fibre (Type IIa) Main characteristics: Higher myosin ATPase activity than Type I fibres High capacity for ATP production via oxidative phosphorylation Dense capillary network High levels of intracellular myoglobin Therefore ... Due to (a), (b) and (c), the main pathway for ATP production is aerobic cellular respiration, the final stage of which is oxidative phosphorylation Due to (c) and (d), their predominant colour is red, as in 'red muscle'.
Recruitment
Force of contraction is increased by increasing the number of muscle fibers contracting by stimulating more motor units.
Outline and discuss the six different types of motion found in synovial joints.
Gliding: movement of relatively flat bone surfaces back and forth and side to side over one another. Angular: increase or decrease in angle between bones. i. Flexion ii. Lateral flexion iii. Extension iv. Hyperextension v. Abduction vi. Adduction vii. Circumduction C. Rotation: movement of bone around longitudinal axis. D. Special: occurs at specific joints. i. Elevation ii. Depression iii. Protraction iv. Retraction v. Inversion vi. Eversion vii. Dorsiflexion viii. Plantar Flexion ix. Supination x. Pronation xi. Opposition Different Synovial Joints: 1. Ball and Socket- hip and shoulder (multiaxial) 2. Hinge- elbow, ankle, knee 3. Pivot Joint- C1 C2 (uniaxial) 4. Condyloid- occipital bone with C1 (biaxial) 5. Gliding- tarsals, carpals, metacarpals 6. Saddle- thumb (biaxial)
What hormones affect the bone growth?
Growth hormone (GH). As its name suggests, GH drives the growth of bones until the adult size is reached. Parathyroid hormone (PTH). It promotes the number and activity of osteoblasts. Estrogens. Until the end of puberty, estrogens are needed for maturation of the skeleton (in males as well as females — Link). In women, after the menopause, taking supplemental estrogen slows up the bone loss that so often leads to osteoporosis. The estrogen induces FasL in osteoclasts causing them to self-destruct by apoptosis and in this way slows up the destruction of bone. Calcitonin and thyroid stimulating hormone (TSH), both of which inhibit the activity of osteoclasts. Calcitriol (1,25[OH]2 vitamin D3. Needed for the deposition of calcium into bone. Osteoprotegerin is a protein secreted by osteoblasts and their precursors (thus a cytokine) that also inhibits the production and activity of osteoclasts. Clinical trials of a recombinant version (made in E. coli) are underway as a possible treatment for various bone-weakening disorders like osteoporosis and multiple myeloma. Leptin, which regulates the balance between osteoblast and osteoclast activity. Serotonin. Secreted by the duodenum, serotonin suppresses osteoblasts (at least in mice). This may account for the bone-weakening effect in humans of prolonged use of selective serotonin reuptake inhibitors(SSRIs).
What is appositional growth?
In cartilage growth, a long bones growth in diameter - on the surface - grows within the perichondrium - cell division takes places - increase in diameter or thickness ( up and down) Osteoblasts beneath the periosteum secrete bone matrix, forming wedges that follow the course of periosteal blood vessels As ridges enlarge and meet, the groove containing the blood vessel becomes a tunnel periosteum lining the tunnel is changed into an endosteum and the osteoblasts below that secrete bone matrix to narrow the canal As osteoblasts below endosteum form new lamellae, a new osteon is created. Are circumferential lamellae are elaborated beneath the periosteum and the process is repeated, continuing to enlarge the bone diameter.
Outline and discuss the different types of contractions.
Isotonic: tension is constant while muscle length changes -Concentric: Concentric- Tension rises above resistance, length of muscle shortens - produces movement. Example: picking up a book -Eccentric: peak tension developed is less than the load and the muscle elongates. Can be due to the contraction of another muscle. Example: lowering a book Isometric: Muscle contracts but doesn't change muscle length. Resistance is too great Examples: holding up a book steady, holding something heavy, muscles that are involved with sitting/standing that oppose the force of gravity.
Classify bones based on shape. Discuss the six categories of bone classification based on shape.
Long Bones: Long and slender, Humerus and Femur Short Bones: Short and small, Carpals and Tarsals Flat Bones: Thin and parallel surfaces, Sternum, Ribs, Scapula Irregular Bones: Complex shape, Vertebrae, Pelvis, Some Skull Bones Sesamoid Bones: Small and flat, shapes like sesame seeds, Patella Sutural Bones: Small, flat, irregularly shaped bones between flat bones of the skull
Outline and discuss four different types of fractures.
Open: the broken end of the bone protrudes through the skin. Comminuted: The bone is splintered, crushed, or broken into pieces at the site of impact. And smaller bone fragments lie between the two main fragments. Greenstick: A partial fracture in which one side of the bone is broken and the other side bends. Occurs only in children whose bones have not fully ossified. Impacted: One end of the fractured bone is forcefully driven into the interior of the other. Pott: Fracture at the distal end of the fibula, with serious injury of the distal tibial articulation. *fracture is defined as a break in the bone* Closed: a fracture that does not break through the skin. Displaced: a serious fracture in which the bones are not in anatomic alignment. Non Displaced: a fracture in which bones remain in their normal alignment. Open: a serious fracture in which broken bones projects through the skin.
What are the functions of synovial fluid?
Reduces friction by lubricating the joint. Absorbs shocks. Supply oxygen and nutrients to Removing carbon dioxide and metabolic waste from the chondrocytes within articular cartilage. Removes microbes and the debris that results from normal wear and tear in the joint. During movement, the synovial fluid held in the cartilage is squeezed out mechanically to maintain a layer of fluid on the cartilage surface. The functions of the synovial fluid include: reduction of friction — synovial fluid lubricates the articulating joints.
Treppe
Repeated stimulation immediately after relaxation phase has been completed. Note an increase in tension observed compared to the previous contraction. Produces a staircase effect because with each stimulation muscle tension increases. This may be due to an increase in calcium/sarcoplasm that wasn't taken back to the TC/SR. Warm up
Outline and discuss the four zones of cartilage found within the growth plate.
Resting Cartilage: near to the epiphysis consist of small, scattered chondrocytes term "resting" is used because the cells doesn't function in bone growth anchors the epiphyseal plate to the epiphysis of the bone Proliferating Cartilage: this layer consists of slightly larger chondrocytes arranged like stacks of coins. these chondrocytes secrete cartilage extracellular matrix and divide to replace chondrocytes that die at the diaphyseal side of the epiphyseal plate Hypertrophic Cartilage: this layer consists of large, maturing chondrocytes arranged in columns. Calcified Cartilage: epiphyseal plate is only a few cells thick and consist mostly of chondrocytes that dead because the extracellular matrix around them has calcified osteoclasts dissolve the calcified cartilage osteoblasts and capillaries from the diaphysis invade the area osteoblast replaces the extracellular matrix with calcified cartilage as a result the zone of calcified cartilage becomes new diaphysis that is firmly cemented to the rest of the diaphysis of the bone
Outline and discuss the functions of the skeletal system.
Support: The skeleton serves as a rigid supporting framework for the soft tissue of the body. Protection: The arrangement of the bones in the skeleton provides protection for many internal organs. Attachment site for skeletal muscles: Skeletal muscles are attached to bones and span across joints between bones. Bones function as levers, enabling movement at joints when skeletal muscles contract. Blood cell production: The red marrow in spongy bone forms red blood cells, white blood cells, and platelets. Mineral storage: The matrix(blood) of bones serves as a storage are for large amounts of calcium phosphate, which may be removed for use in other parts of the body when needed. Triglyceride Storage: in yellow bone marrow
Discuss the difference between the axial and appendicular skeleton.
The Axial Skeleton makes up the central bony axis of the body. The appendicular skeleton is composed of the appendages or extremities, including the supporting structures.
Wave stimulation:
The second stimulus arrives before relaxation completes. (Note the intensity of the stimulus is always the same). Wave summation = one twitch is added to another. The increase in tension results from the muscle already being partially contracted from the previous stimulus.
Identify the bone cells and what do they do.
There are two categories of bone cells. Osteoclasts are in the first category. They resorb (dissolve) the bone. The other category is the osteoblast family, which consists of osteoblasts that form bone, osteocytes that help maintain bone, and lining cells that cover the surface of the bone.
