Anatomy and Physiology Bone Muscle Lecture Test

Heat Production During Muscle Activity

~ 40% of the energy released in muscle activity is useful as work Remaining energy (60%) given off as heat Dangerous heat levels are prevented by radiation of heat from the skin and sweating

dorsiflexion

bending of the foot or the toes upward

plantar flexion

bending of the sole of the foot by curling the toes toward the ground

Wolff's Law

bone grows or remodels in response to the demands placed on it

inversion

Turning the sole of the foot inward

Effort

the applied force used to move a resistance

appositional growth

"growth from outside"- cartilage forming cells in surrounding perichondrium secrete new matrix against the external face of existing cartilage tissue

intersitial lamellae

- Incomplete lamellae lying between intact osteons - Fill gaps between forming osteons or are remnants of osteons that have been cut through by bone remodeling

3 steps process in generation and propagation of an action potential

- depolarization and generation - action potential is propagated - repolarization

aerobic respiration

95% of ATP used for muscle activity during rest and light to moderate exercise

Actin

A globular protein that links into chains, two of which twist helically about each other, forming microfilaments in muscle and other contractile elements in cells.

Troponin

A protein of muscle that together with tropomyosin forms a regulatory protein complex controlling the interaction of actin and myosin and that when combined with calcium ions permits muscular contraction

Myosin

A protein present in muscle fibers that aids in contraction and makes up the majority of muscle fiber

lever

A rigid bar that is free to move around a fixed point

cocking of myosin head

As ATP is hydrolyzed to ADP and Pi, the myosin head returns to its prestroke high-energy, or "cocked" position

cross bride detachment

As a new ATP molecule binds to the myosin head, myosin holds on actin looses and bridge detached from actin

cardiac muscle

Beating of cardiac Muscle

closed

Bone ends are coaxed together by doctor

open

Bone ends are surgically wired or pinned together

thick filaments

Central, extends the entire length of A band Myosin

Perimysium

Connective tissue surrounding a fascicle

Endomysium

Connective tissue surrounding a muscle fiber

flexion

Decreases the angle of a joint

Alkaline phosphatase

Enzyme shed by osteoblasts, essential for mineralization and part of matrix proteins that bind and concentrate calcium

thin filaments

Extends across the I band and partway into the A band Actin Z disc coin shape - Composed of Nebulin

Osteon

Groups of hollow tubes of bone matrix

regulating proteins

Help control the myosin actin interactions involved in contractions

blood cell formation

Hematopoiesis occurs in marrow cavities of certain bones

Control of Remodeling

Hormonal mechanisms that maintain calcium homeostasis in the blood Mechanical and gravitational forces

Linear

If the break is parallel to the long axis

Transverse

If the break is perpendicular to the bones long axis

hinge joint

Joint between bones (as at the elbow or knee) that permits motion in only one plane

terminal cisternae

Large perpendicular cross channels at the A band and I band junction

spongy bone

Layer of bone tissue having many small spaces and found just inside the layer of compact bone.

Lamella

Layers of bone matrix

calcification front

Located between osteoid seam and older mineralized bone

Skeletal

Locomotion or Manipulation

compact bone

Looks solid and dense but riddled with passageways that serve as conduit for nerves, blood vessels and lymphatic

abduction

Movement away from the midline of the body

opposition

Movement of the thumb to touch the fingertips

adduction

Movement toward the midline of the body

indirect

Muscle CT wrapping extend beyond the muscle

bone deposit

Occurs where bone is injured or added strength is needed; Requires a diet rich in protein; vitamins C, D, and A; calcium; phosphorus; magnesium; and manganese

muscle fiber contraction

Once myosin binding sites on actin are exposed 4 events occur

condyloid joint

Oval articular surface of one bone fits into a complementary depression in another ex. knuckles

Smooth

Propels or squeeze substances through organs and along a tract

muscle metabolism

Providing energy for contraction

incomplete tetanus

Quivering contraction due to stimulus coming at faster rates so that the relaxation phase between the twitches are shorter

Fibrocartilagenous callus formation

Restructure, Splints the bone, formation of soft granulation tissue (Callus)

Movement

Skeletal muscles which attach to bones by tendons use bones as levers to move the body

synaptic cleft

Space separating axonal ending and muscle fibers

Haversian system or Osteon System

Structural unit of bone

support

Supports the body and cradles it's soft organs

bone remodeling

The continuous turnover of bone matrix and mineral that involves first, an increase in resorption and osteoclast activity, and later, reactive bone formation by osteoblast activity.

fulcrum

The fixed point around which a lever pivots

protection

The fused bones of the skull protect the brain.

Depolarization

The process during the action potential when sodium is rushing into the cell causing the interior to become more positive.

Osteiod seam

Unmineralized band of gauzy-looking bone matrix

origin

When muscle contracts the insertion moves toward the origin

hematoma formation

a mass of clotted blood, forms at the fracture site

motor unit

a motor neuron and its associated muscle fibers

primary ossification center

a region where bone tissue will replace most of the cartilage (Hyaline)

Tropomyosin

a rod-shaped protein, spiral about the actin core and help stiffen and stabilize it

Stored ATP

a small amount of ATP is stored in muscles -used for first few seconds of exercise

Elasticity

ability of a muscle fiber to recoil and resume its resting length after being stretched

Excitability (irritability)

ability to receive and respond to stimuli

Contractility

ability to shorten forcibly when stimulated

medial rotation

anterior surface moves toward midline

Bone repair

blood clot formation, fibrocartilage callus, bony callus, bone remodeling

intramembranous ossification

bone develops from a fibrous membrane (Cranial Bones of the skull- Frontal Parietal Occipital Temporal)

displaced fracture

bone ends are out of normal alignment

nondisplaced fracture

bone ends retain their normal position

Osteoblasts

bone forming cells

lever system

bone-muscle relationship

bony callus formation

bony tissue fills the area, creating a hard callus

Osteoclasts

break down bone matrix

closed (simple) fracture

break that does not penetrate the skin

complete fracture

broken all the way through

open (compound) fracture

broken bone penetrates through the skin

Fascicle

bundle of muscle fibers

elastic filaments

composed of the protein Titin which anchors the Thick Filaments

Bone Homeostasis

consists of bone remodeling and bone repair. (Recycle 5-7% of our bone mass every week)

Haversian canal

contains small blood vessels & nerve fibers

generating heat

contracting muscle produces heat shivering increases heat production

period of contraction

cross bridges are active, from the onset to the peak of tension development, and the myogram tracing rises to a peak

second class lever

effort is applied at one end of the lever and the fulcrum is located at the other, with the load between them (ex: wheelbarrel)

third class lever

effort is between the fulcrum and the resistance

tendon sheath

elongated bursa that wraps completely around a tendon

T tubules

elongated tube; formed by the cell interior in sarcolemma of cell muscle that protrudes deep into cell interior; increase muscle fibers surface area

direct (fleshy) attachment

epimysium fused to periosteum of bone or perichondrium of cartilage

Myofilaments

filaments of myofibrils, constructed from proteins, principally myosin or actin

hormonal regulation

growth hormone, thyroid hormone, testosterone and estrogen, PTH, and calcitonin

postnatal bone growth

growth in length of long bones

cross bridge formation

high-energy myosin head attaches to actin thin filament active site

connective tissue sheaths

hold together and wrap around individual muscle fibers; support each cell and reinforce the muscle as a whole ( Endomysium, perimysium, fascicles, Epimysium)

extension

increases the angle of a joint

period of relaxation

initiated by reentry of Ca in the SR

intersitial growth

lacunae-bound chondrocytes inside the cartilage divide and secrete new matrix, expanding the cartilage from within

Volkmann's canals

lie at right angles to the long axis of the bone and connect the blood and nerve supply of the medullary cavity to the central canals

Elevation

lifting a body part superiorly

circumferential lamellae

located deep to periosteum and superficial to endosteum and extend around entire circumference of the diaphysis and resist twisting of long bone

Osteocytes

mature bone cells

Insertion

movable bone

circumduction

movement of a limb so that it describes a cone in space

protraction

moving a body part forward

Depression

moving a body part inferiorly

depression

moving a body part inferiorly

retraction

moving a part backward

eccentric

muscle contractions lengthen

concentric

muscle shortens and does work

isotonic contraction

muscles contract and shorten

working stroke

myosin head pivots and pulls thin filament toward M line

complete tetanus

no relaxation between contractions

Protraction

nonangular anterior movements in a transverse plane

Retraction

nonangular posterior movement in a transverse plane

incomplete fracture

not broken all the way through

Epimysium

overcoat of dense irregular connective tissue that surrounds the whole muscle

weeping lubrication

pressure on joints squeezes synovial fluid into and out of articular cartilage

endochondral ossification

process in which bone forms by replacing hyaline cartilage

collagen fibers

provides flexibility and strength

elevation

raising a body part superiorly

reduction

realignment of broken bone ends

Sacromere

region between two successive Z discs Contains A band and 1/2 i band Functional unit of skeletal muscle

neuromuscular junction

region where a motor neuron comes into close contact with a skeletal muscle cell

Striations

repeating series of dark and light bands

mineral storage

reservoir for minerals, especially calcium and phosphorus

load

resistance

maintain posture

skeletal muscles maintain constant tone

Myofibrils

rodlike and run parallel to length of muscle fibers

pivot joint

rotating bone turns around an axis; ex. connection between radius/ulna and humerus

lateral rotation

rotation away from the midline

Pronation

rotation of the hands and forearms so that the palms face downward

Supination

rotation of the hands and forearms so that the palms face upward

medial rotation

rotational movement towards the midline

plane joint

short slipping or gliding movements; ex. carpals

gliding movements (translation)

simplest joint movement since a flat bone moves or slips over another

synaptic vesicles

small membranous sacs containing neurotransmitter

Inversion

sole of foot inward

Eversion

sole of foot turns laterally

sacroplasmic reticulum

specialized smooth endoplasmic reticulum, releases calcium on demand when the muscle fiber is stimulated to contract

ball and socket joint

spherical head of one bone fits into a round socket in another ex. shoulder, hip

Treppe

stepwise increase in contraction tension

maximal stimulus

strongest stimulus that increases contractile force

Extensibility

the ability to be stretched or extended

oxygen debt

the amount of oxygen required after physical exercise to convert accumulated lactic acid to glucose

bone resorption

the breakdown of bone extracellular matrix by osteoclasts that is part of the normal development, maintenance, and repair of bone tissue

first class lever

the effort is applied at one end of the lever and the load is at the other, with the fulcrum somewhere between

Acetylcholinesterase

the enzyme that breaks down acetylcholine in the synaptic cleft (located neuromuscular junction )

Triads

the grouping of one T-tubule and two terminal cisternae

muscle fatigue

the physiological inability of a muscle to contract

Repolarization

the process of restoring the normal resting membrane potential after depolarization

muscle twitch

the response of a muscle to a single brief threshold stimulus

muscle tone

the state of balanced muscle tension muscle tendons that cross the joint are the most important stabilizing factor

threshold stimulus

the stimulus at which the first observable contraction occurs

isometric contraction

the tension generated is not enough to exceed the resistance of the object to be moved, and the muscle does not change its length

wave summation

this occurs when a second stimulus is received before the muscle fiber has relaxed, creating a second contraction that is stronger than the first

latent period

time between stimulus and contraction

motor end plate

troughlike part of the muscle fiber's sarcolemma that helps form the neuromuscular junction

pronation

turning the palm downward

supination

turning the palm upward

eversion

turning the sole of the foot outward

saddle joint

type of joint found at the base of each thumb; allows grasping and rotation

graded muscle responses

variations in the degree of muscle contraction by changing either the frequency or strength of the stimulus