Ap-Chapter10

Front 1

Motor unit

Back 1

A single somatic motor neuron & all the muscle fibers it stimulates

Front 2

Muscular atrophy

Back 2

Wasting away of muscle due to lack of use

Front 3

Fibrosis

Back 3

The replacement of skeletal muscle fibers with scar tissue

Front 4

Somatic motor neurons

Back 4

Provide the nerve impulses that stimulate skeletal muscle to contract

Front 5

4 properties of muscle tissue

Back 5

Electrical excitability
Contractility
Extensibility
Elasticity

Front 6

Myofibrils

Back 6

The contractile elements of skeletal muscle
Composed of 3 types of proteins: contractile, regulatory and structural

Front 7

Excitability

Back 7

The ability of muscle cells to respond to stimuli and produce electrical signals

Front 8

Sequence of events resulting in muscle contraction

Back 8

1. Nerve impulse
2. Release of acetylcholine
3.Muscle action potential
4. Release calcium ions from sarcoplasmic reticulum
5. Calcium ion binding to troponin
6. Power stroke, actin & myosin binding & release

Front 9

Tintin

Back 9

Structural protein, connects z disc to m line of the sarcomere, stabilize position.

Front 10

Sacromere

Back 10

Basic functional units of myofibril, in muscle fiber

Front 11

Z discs

Back 11

Narrow plate-shaped regions of dense protein that separate one sarcomere from the next

Front 12

M line

Back 12

Region in center of the H zone that contain proteins that hold thick filaments together at the center of the sarcomere

Front 13

Components of Sarcomere

Back 13

z discs, a band, I band, H zone, M line

Front 14

A band

Back 14

Dark middle part of sarcomere, extends entire length of filament

Front 15

I band

Back 15

Lighter less dense area of sarcomere, no thick filaments

Front 16

H zone

Back 16

Narrow region in center of each A band, contains thick filaments

Front 17

Myosin

Back 17

Contractile motor protein

Front 18

Tropomyosin

Back 18

Regulatory protein that blocks myosin-binding sites

Front 19

Actin

Back 19

Contracile protein that contains myosin-binding sites

Front 20

Calsequestrin

Back 20

Calcium-binding protein

Front 21

Sources of ATP for muscle contraction

Back 21

Creatine phosphate
Glycolysis
Anaerobic cellular respiration
Aerobic cellular respiration

Front 22

Endomysium

Back 22

Sheath of areolar connective tissue that wraps around individual skeletal muscle fibers

Front 23

Perimysium

Back 23

Dense irregular connective tissue that separates a muscle into groups of individual muscle fibers

Front 24

Fascicles

Back 24

Bundles of muscle fibers

Front 25

Epimysium

Back 25

Outermost connective tissue layer, encircles entire skeletal muscle

Front 26

Fascia

Back 26

Dense irregular connective tisuuse, lines body wall, holds functional muscle units together.

Front 27

Tendon

Back 27

Cord of dense regular connective tissue, attaches muscle of periostium of bone

Front 28

Muscle fiber

Back 28

Muscle cell

Front 29

Aponeurosis

Back 29

Connective tissue elements, extend as broad flat layer

Front 30

Tendon sheath

Back 30

2 layer tube of fibrous connective tissue enclosing certain tendons

Front 31

Neuromusclar junction

Back 31

Synapse btwn a motor neuron and a muscle fiber

Front 32

Transverse tubules

Back 32

Invaginations of the sarcolemma from the surface toward the center of the muscle fiber

Front 33

Satellite cells

Back 33

Myoblasts that persist in mature skeletal tissue

Front 34

Sarcolemma

Back 34

Plasma membrane of a muscle fiber

Front 35

Myoglobin

Back 35

Oxygen-binding protein found only in muscle fibers

Front 36

Sarcoplasmic reticulum

Back 36

Ca2+ storing tubular system similar to smooth ER

Front 37

Sarcomere

Back 37

Contracting unit of skeletal muscle fiber

Front 38

Sarcoplasm

Back 38

Cytoplasm of muscle fiber

Front 39

Skeletal muscle

Back 39

Striated, no autorhythmicity, uses satellite cells to repair damages fiber

Front 40

Cardiac muscle

Back 40

Fibers joined by intercalated discs, striated, has extended contraction due to prolonged calcium delivery, uses troponin as regulatory protein, can be autorhythmic

Front 41

Smooth muscle

Back 41

No arranged in sarcomeres, contraction begins slowly but lasts long time, uses pericytes to repair, can be autorhythmic, uses calmodulin as regulatory protein

Front 42

Stress-relaxation response

Back 42

Smooth muscle action that allows the fibers to maintain their contractile function even when stretched

Front 43

Twitch contraction

Back 43

Brief contraction of all the muscle fibers in a motor unit in response to a single action potential in its motor neuron

Front 44

Fused tetanus

Back 44

Sustained contraction, no relaxation btwn stimuli

Front 45

Wave summation

Back 45

Larger contraction resulting from stimuli arriving a different times

Front 46

Motor unit recruitment

Back 46

Process of increasing the # of activated motor units

Front 47

Concentric isotonic contraction

Back 47

Contraction in which the muscle shortens

Front 48

Muscle fatigue

Back 48

Inability of muscle to maintain its strength of contraction during prolonged activity

Front 49

Unfused tetanus

Back 49

Sustained but wavering contraction with partial relaxation btwn stimuli

Front 50

Muscle tone

Back 50

Produced by continual involuntary activation of a small # of skeletal motor units, results in firmness

Front 51

Isometric contraction

Back 51

Contraction where muscle tension is generated without shortening of muscle

Front 52

Recovery oxygen uptake

Back 52

Amount of O2 needed to restore the body's metabolic conditions back to resting levels after exercise

Front 53

Eccentric isotonic contraction

Back 53

Contraction in which a muscle lengthens

Front 54

Perimysium bundles...

Back 54

Groups of muscle fibers into fasicles

Front 55

Sarcoplasmic Reticulum releases..

Back 55

Calcium ions to trigger muscle contractions

Front 56

Sarcomeres are separated by?

Back 56

Z discs

Front 57

What bands/zones disappear during muscle contraction?

Back 57

I and H

Front 58

If ATP were not available what would happen?

Back 58

Crossbridges would not detach from actin, muscle would remain rigid

Front 59

Motor end plate

Back 59

Part of sarcolemma that contains acetylcholine receptors