Anatomy and Physiology Chapters 4-7

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skeletal system

composed of bones, cartilage, and ligaments joined tightly to form a strong, flexible framework for the body

tendons

connect muscle to bone and are the most important structure in stabilizing a joint

tendon

connective tissue cords or sheets that attach skeletal muscles to bones o Aponeurosis - tendon that is a broad sheet

Epimysium

connective tissue layer surrounding the muscle as a whole

perimysium

connective tissue sheath surrounding a fascicle

Joint (articular) capsule

connective tissue that encloses the joint cavity o Consists of an outer fibrous capsule that encloses the whole joint o and an inner synovial membrane that secretes the synovial fluid

stem cells

continually divide to produce new keratinocytes

Flexion

decreases the joint angle on the sagittal plane (usually involves bending the joint forward if it can move that way)

muscle tissue

description: Tissue composed of elongated, excitable cells function: Specialized for contraction and movement ex: Skeletal muscles, heart, walls of hollow organs and blood vessels

nervous tissue

description: Tissue containing excitable cells that can also generate a signal function: Specialized for rapid transmission of information to other cells ex: Brain, spinal cord, nerves

connective tissue

description: Tissue with more matrix than cell volume function: Usually specialized to support, bind, or protect organs. Blood is used for transport ex:Tendons, ligaments, cartilage, bone, fat, blood

epithelial tissue

description:Composed of layers of closely spaced cells function:Covers organ surfaces, forms glands, serves for protection, secretion and absorption ex:Epidermis, lining hollow organs, glands

Four tissue classes

epithelial, connective, nervous and muscular

Hyperextension

extends a joint beyond anatomical position

yellow bone marrow

fatty substance that fills long bones in adults

periosteum

fibrous connective tissue sheath covering the external surface of a bone

Fascia

fibrous sheets that separate adjacent muscles from each other

inversion

foot movement that tilts the soles medially toward each other

ossification

formation of bone

secretion

gland's product if it is useful

First gap phase (G1)

he interval between cell division and DNA replication

Articular cartilages:

hyaline cartilage that covers the facing bone surfaces

compact (dense) bone

is solidly filled with opaque matrix. Is always found on the surface of a bone Organized into osteons (cylindrical units of bone structure) Layers of matrix called lamellae arranged concentrically around a central canal, which contains blood vessels and nerves

Hair matrix

just above the dermal papilla, is the exclusive site of cellular mitosis and hair growth

Stratum spinosum

many layers of keratinocytes and some dendritic cells; these keratinocytes stop dividing and start synthesizing keratin

Epiphyseal lines

mark former growth zones from childhood

osteocytes

mature bone cells (former osteoblasts) that have become trapped in the matrix they deposited

Dorsiflexion

movement in which the toes are raised

abductions

movement of a body part away from the midline

Opposition

movement of the thumb to approach the fingertips

plantar flexion

movement that points the toes downward

adduction

movement toward the midline, returning to zero position

matrix

non-living extracellular material

merocrine sweat glands

numerous, and especially abundant on palms, soles and forehead ducts lead to skin surface; produce watery perspiration that serves to cool the body;Sweat has a pH ranging from 4-6

red bone marrow

o Produces red blood cells and platelets o fills all bones in children, fills spongy bone in adults

apocrine sweat gland

o ducts lead onto hair follicles o secretion contains more fatty acids than merocrine sweat glands o especially respond to stress and sexual stimulation o produce pheromones (chemicals that influence the physiology or behavior in other members of the species)

cerumionous glands

o found only in the auditory canal o secretion combines with sebum and dead epidermal cells to form cerumen (ear wax) o ducts lead to the skin surface o cerumen keeps eardrum pliable, waterproofs the auditory canal and has a bactericidal effect

osteoblasts

o function to synthesize and deposit matrix o develop from osteogenic cells, lie on the bone surface

osteoclasts

o large, multinucleated, bone-dissolving cells o lie on the bone surface

sebaceous glands

o produce an oily secretion (sebum) o short ducts open into a hair follicle o Sebum keeps the skin and hair from becoming dry, brittle and cracked

Osteogenic cells

o stem cells that occur on the bone surface o they are the only cells capable of dividing and making more bone cells

Circumduction

one end of the appendage remains mostly stationary while the other makes a circular movement

motor unit

one motor neuron and all the muscle fibers supplied by it small motor units supply a small number of muscle fibers, are easily stimulated to excite them and are involved in weak muscle contractions large motor units supply larger numbers of muscle fibers, require a stronger stimulus to excite them and are involved in stronger muscle contractions

Sarcolemma

plasma membrane of a muscle cell

Retraction

posterior movement

serous gland

produce a thin, watery fluid (like sweat, milk, tears)

melanocytes

produce the dark pigment melanin, which protects the deeper tissues from UV rays in the sunlight

Intramembranous Ossification

produces flat bones of skull a. Begins with a sheet of mesenchyme (embryonic connective tissue) b. Osteoblasts deposit immature bone matrix ("osteoid"), which then hardens c. Osteoblasts trapped in the matrix become osteocytes d. Spaces where there isn't bone fills with blood vessels and red marrow

Endochondral Ossification

produces most of the bones in the body a. Begins with hyaline cartilage b. Formation of primary ossification center (in the diaphysis), bony collar and periosteum c. Vascular invasion, formation of the primary marrow cavity d. Appearance of the secondary ossification center e. Secondary ossification center develops in the epiphyses f. Vascular invasion, formation of the secondary marrow cavity g. Epiphyseal plates close

elevation

raises a body part vertically

Parathyroid hormone (PTH)

raises blood calcium by stimulating bone resorption by osteoclasts

Calcitriol (Vitamin D)

raises blood calcium by stimulating osteoclasts and promoting calcium absorption from food

Sphincter muscles

ring-shaped muscles that control the diameter of an opening

supination

rotation of the forearm so that the palm faces forward or upward

pronation

rotation of the forearm so that the palm faces toward the rear or downward

mucous gland

secrete a protein that absorbs water and becomes mucus (secreted on the respiratory and digestive tracts)

tactile cells

sensory cells for the sense of touch

atrophy

shrinkage of a tissue through a loss in cell size or number, due to lack of use or aging

synovial fluid

slippery lubricant that fills the joint cavity

bone marrow

soft bloody or fatty material enclosed in bones

extension

straightens a joint and returns the body part to anatomical ("zero") position

what type of cells protect the body from abrasion?

stratified squamous cells; linked by desmosomes

functions of skeleton

support; protection; movement; blood formation; storage

cuticle

surface of the hair

pallor

temporary pale or ashen color, results when there is little cutaneous blood flow and skin color is dominated by white dermal collagen o can result from emotional stress, circulatory shock, cold temperatures, or severe anemia

reticular layer

the bulk of the dermis, zone of dense irregular CT. Is very tough (think of the leather of animal hides, which is made from this layer)

differentiation

the development of specialized tissue from stem cells

Cytokinesis:

the division of the cytoplasm

Shaft/diaphysis

the elongated midsection of long bones, provides leverage

Head/epiphysis

the expanded end of a long bone. Functions to strengthen a joint and provide added surface area for a tendons and ligaments

osseous tissue

the hard, calcified tissue of a bone Osseous tissue consists of cells and matrix. Like other connective tissues, the matrix is made of fibers and ground substance

Medullary cavity

the hollow space(s) inside of a bone, filled with marrow

Second gap phase (G2)

the interval between DNA replication and cell division

Prime mover (agonist)

the muscle that produces most of the force during a particular joint action

motor neurons

the nerve cells that stimulate skeletal muscles at the distal end, the axon (also called a nerve fiber) branches to multiple muscle fibers, but each muscle fiber receives only one nerve fiber

depression

the opposite of elevation

Synthesis phase (s)

the period in which a cell replicates its DNA The DNA is unzipped and the nitrogen bases are exposed DNA polymerase (an enzyme) assembles complementary nucleotides for each strand

Mitotic phase (M)

the period in which a cell replicates its nucleus and divides its DNA into two identical sets Prophase, Metaphase, Anaphase, Telophase

synapse

the point where the end of a nerve fiber meets another cell

Excitation

the process of converting an electrical nerve signal to an electrical signal in the muscle fiber

hemoglobin

the red pigment of blood imparts a reddish or pink hue to the skin as blood vessels show through the dermal collagen

fibrosis

the replacement of damaged tissue with scar tissue (collagen) The tissue is held together but does not have its normal function

regeneration

the replacement of dead or damaged cells by the same type of cells as before, thus restoring the normal function Many epithelial tissues are excellent at this (especially the skin and liver)

Sarcoplasmic reticulum (SR)

the smooth endoplasmic reticulum of a muscle fiber It's web wraps around each myofibril It functions as a reservoir for calcium ions When the muscle fiber is stimulated, the SR releases calcium ions into the cytosol to activate the contraction process

Contraction

the step in which the muscle fiber develops tension and may shorten

histology

the study of tissues

Reposition

the thumb's movement back to zero position

Dermal papillae

the upward waves of connective tissue that interlock with the epidermis o this reduces slippage of the epidermis across the dermis, and also produces fingerprints

Articular cartilage

thin layer of hyaline cartilage that covers the ends of bones in a joint

endosteum

thin layer of reticular connective tissue lining that separates the marrow from the bone

Papillary layer

thin zone of areolar connective tissue (CT) beneath the epidermis, filling the dermal papillae

stratum lucidum

this is only present in the thick epidermis of the palms and soles. It is a thin, clear layer of dead cells

eversion

tilts the soles away from each other

synaptic cleft

tiny gap between the nerve fiber and the muscle fiber

hyperplasia

tissue growth though cell multiplication

Transverse (T) tubules

tunnel like infoldings of the plasma membrane Functions to carry an electrical current from the surface of the cell to the interior of the cell

Stratum corneum

up to 30 layers of dead, keratin-packed keratinocytes. The dead cells exfoliate (flake off) from the surface

excretion

waste product of a gland

neuromuscular junction (NMJ)

when a nerve fiber meets a muscle cell

Relaxation

when a nerve stops stimulating the muscle cell, the muscle cell relaxes and returns to its resting length.

carotene

yellow pigment acquired from foods, can become concentrated in the stratum corneum and hypodermis

spongy bone

a porous lattice filled with blood-filled spaces. Is always found in the interior of a bone

flat bones

Act as protective plates covering delicate organs (sternum and skull) or as a broad attachment point for muscles (scapula) Consist of two layers of compact bone enclosing a middle layer of spongy bone

dermis

Consists of fibrous connective tissue, is mostly collagen Well supplied with blood vessels, sweat glands, sebaceous (oil) glands, and nerve endings

Functions of Muscles

Movement Stability of joints Control of body openings and passages Heat generation Glycemic control (regulation of blood glucose) - skeletal muscles play a significant role in stabilizing blood glucose levels by absorbing a large share of it

Cartilaginous joints

Other name: amphiarthrosis Structure: adjacent bones are bound by cartilage Mobility: varies, but can be a little movement Examples: o pubic symphysis (where fibrocartilage joins the right and left bones together) o intervertebral discs (fibrocartilage joins consecutive vertebrae to each other)

Synovial joints

Other name: diarthrosis Overall structure: adjacent bone surfaces are covered in hyaline cartilage and surrounded by a joint cavity that is filled with fluid Mobility: most are highly mobile Examples: o knee joint, elbow, finger joints, hip, shoulder, jaw and most other joints in the body

Fibrous joints

Other name: synarthrosis Structure: adjacent bones are bound by collagen fibers Mobility: most have very little Examples: o skull sutures o joint between the radius and ulna (the interosseus membrane) o joint between the tibia and fibula

The Hip (JOINT)

Structure: the head of the femur inserts into the acetabulum of the hip socket Other features: the acetabular labrum is a ring of fibrocartilage around the rim of the acetabulum, which deepens the socket Stabilization comes from three ligaments (iliofemoral, pubofemoral, ischiofemoral)

The shoulder (JOINT)

Structure: the head of the humerus inserts into a shallow glenoid cavity of the scapula Other features: the glenoid labrum is a ring of fibrocartilage around the rim of the glenoid cavity, which deepens the socket Stabilization comes from o primarily from the tendon of the biceps brachii muscle o rotator cuff: tendons of four scapular muscles (arise from the scapula) reinforce the joint capsule

The jaw (temperomandibular joint, TMJ) (JOINT)

Structure: the mandibular condyle of the mandible inserts into the mandibular fossa of the temporal bone

dystrophin

dystrophin is a protein that connects myofilaments to the sarcolemma and extracellular matrix If dystrophin does not function correctly, the sarcolemma will tear and the muscle tissue will eventually be scarred. With time, the muscle is replaced with adipose and scar tissue, resulting in paralysis. (This is occurs in Muscular Dystrophy)

serous membrane (serosa)

line the thoracic and abdominal cavities, cover the external surfaces of organs composed of a simple squamous epithelium produce a thin, watery fluid

mucous membranes

line tracts of the body that open to the exterior environment (digestive, respiratory, urinary and reproductive tracts) are covered by mucus that traps bacteria and foreign particles

hypodermis

looser CT and adipose tissue binds the skin to underlying muscles subcutaneous fat pads the body, serves as a energy reservoir, provides thermal insulation

necrosis

pathological death of tissue due to trauma, toxins, infection, etc. Often spreads

apoptosis

programmed cell death, the normal death of cells that have completed their function. This is caused by lysosomes that degrade the cell's DNA and proteins does not spread from cell to cell

exocrine gland

release a secretion onto an epithelial surface release a secretion through a duct Examples: sweat glands, salivary glands, mammary glands, liver Further classified by the type of secretion

endocrine glands

release their products into the bloodstream, do not have ducts the secretion is a hormone, which serves as a chemical signal to other organs Examples: pituitary gland, thyroid gland, adrenal glands

why can few infections organisms penetrate the skin?

skin cells are packed with a tough protein (keratin) skin is dry skin is covered with an acidic film

hair receptors

(nerve fibers) coil around the follicle and respond to hair movements

keratinocytes

cells packed with keratin

dendritic cells

cells that alert the immune system to foreign invaders

medulla

centeal core that's only present in thick hairs (i.e.: eyebrows and lashes)

tendons

collagen bands that attach muscle to bone

Stratum granulosum

3-5 layers of keratinocytes with dark-staining granules. Keratin filaments clump together and form a water-proofed layer. The cells die here as a result.

ligaments

collagen bands that hold bones together at the joints

thermoregulation

The skin stabilizes body temperature by regulating heat exchange with the environment o blood flow near the skin is reduced to retain heat o blood flow near the skin is increased to prevent overheating

Dermal papilla

a bit of vascular CT that grows into the bulb and provides the hair with its sole source of nutrition

Hematoma

a bruise, a mass of clotted blood showing through the skin o can result from trauma, platelet deficiencies, anticoagulant drugs, or hemophilia

Fascicle -

a bundle of muscle fibers

gland

a cell or organ that releases substances for use elsewhere in the body or for elimination from the body

Mineral deposition

a crystallization process in which osteoblasts extract calcium and phosphate from the blood and deposit it in the osseous tissue

hair follicle

a diagonal tube of epithelium and connective tissue that penetrates the dermis

bursa

a fibrous sac filled with synovial fluid, acts to cushion muscles or help tendons slide more easily over the joints

tissue

a group of similar cells and cell products that work together to perform a specific function

albinism

a hereditary lack of pigmentation in the skin, hair and eyes due to an inability to synthesize melanin

epidermis

a keratinized stratified squamous epithelium composed of keratinocytes, dendritic, melanocytes, tactile, and stem cells

Synergista muscle

a muscle that aids the prime mover. The synergist may stabilize a joint, restrict unwanted movements, or modify the direction of the movement so that the action of the primary mover is more coordinated and specific

anatagonist

a muscle that opposes the prime mover

Fixator

a muscle that restricts a bone from moving, holding it steady so that another muscle attached to it can pull on something else

Joint (articular) cavity

a narrow space separating the two bones

Articular cartilage/disc

a pad that crosses the entire joint

meniscus

a pad that doesn't cross the entire joint

resorption

a process in which the osteoclasts dissolve bone, releasing the minerals into the blood and making them available for other uses

stratum basale

a single layer of stem cells, keratinocytes, melanocytes and tactile cells

hair

a slender filament of keratinized cells that grows from a hair follicle Hair is made from a harder keratin than what's in the skin

Piloerector muscles

a small smooth muscle attached the hair follicle. When it contracts, pulls the follicle into a vertical position

Endomysium -

a thin sleeve of loose connective tissue that encloses a single muscle cell (which is also called a muscle fiber) o As an insulator, it prevents electrical activity in one muscle cell from directly stimulating adjacent fibers

jaundice

a yellowing of the skin and whites of the eyes o occurs in various liver diseases (cancer, hepatitis, cirrhosis and some blood diseases with a rapid rate of erythrocyte breakdown)

Erythema

abnormal redness of the skin (as in sunburn, exercise, hot weather, embarrassment)

Protraction

anterior movement on a horizontal plane

cortex

beneath the cuticle, makes the bulk of hair

Cyanosis

blueness of the skin resulting from oxygen deficiency in the blood or reduced dermal blood flow in cold weather

axon terminal

bulbous swelling at the end of a nerve fiber/axon

Myofibrils

bundles of contractile proteins Myofilaments - parallel protein filaments that make up a myofibril Thick filaments are made of the protein myosin Thin filaments are made of the protein actin o A thin filament also has two proteins (troponin and tropomyosin) that act together as a molecule switch that either allows or prohibits muscle contraction


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