Ch. 10 Vocabulary

Front 1

acetylcholine (ACh)

Back 1

neurotransmitter that binds at a motor end-plate to trigger depolarization

Front 2

actin

Back 2

protein that makes up most of the thin myofilaments in a sarcomere muscle fiber

Front 3

action potential

Back 3

change in voltage of a cell membrane in response to a stimulus that results in transmission of an electrical signal; unique to neurons and muscle fibers

Front 4

aerobic respiration

Back 4

production of ATP in the presence of oxygen

Front 5

angiogenesis

Back 5

formation of blood capillary networks

Front 6

aponeurosis

Back 6

broad, tendon-like sheet of connective tissue that attaches a skeletal muscle to another skeletal muscle or to a bone

Front 7

ATPase

Back 7

enzyme that hydrolyzes ATP to ADP

Front 8

atrophy

Back 8

loss of structural proteins from muscle fibers

Front 9

autorhythmicity

Back 9

heart's ability to control its own contractions

Front 10

calmodulin

Back 10

regulatory protein that facilitates contraction in smooth muscles

Front 11

cardiac muscle

Back 11

striated muscle found in the heart; joined to one another at intercalated discs and under the regulation of pacemaker cells, which contract as one unit to pump blood through the circulatory system. It is under involuntary control

Front 12

concentric contraction

Back 12

muscle contraction that shortens the muscle to move a load

Front 13

contractility

Back 13

ability to shorten (contract) forcibly

Front 14

contraction phase

Back 14

twitch contraction phase when tension increases

Front 15

creatine phosphate

Back 15

phosphagen used to store energy from ATP and transfer it to muscle

Front 16

dense body

Back 16

sarcoplasmic structure that attaches to the sarcolemma and shortens the muscle as thin filaments slide past thick filaments

Front 17

depolarize

Back 17

to reduce the voltage difference between the inside and outside of a cell's plasma membrane (the sarcolemma for a muscle fiber), making the inside less negative than at rest

Front 18

desmosome

Back 18

cell structure that anchors the ends of cardiac muscle fibers to allow contraction to occur

Front 19

eccentric contraction

Back 19

muscle contraction that lengthens the muscle as the tension is diminished

Front 20

elasticity

Back 20

ability to stretch and rebound

Front 21

endomysium

Back 21

loose, and well-hydrated connective tissue covering each muscle fiber in a skeletal muscle

Front 22

epimysium

Back 22

outer layer of connective tissue around a skeletal muscle

Front 23

excitability

Back 23

ability to undergo neural stimulation

Front 24

excitation-contraction coupling

Back 24

sequence of events from motor neuron signaling to a skeletal muscle fiber to contraction of the fiber's sarcomeres

Front 25

extensibility

Back 25

ability to lengthen (extend)

Front 26

fascicle

Back 26

bundle of muscle fibers within a skeletal muscle

Front 27

fast glycolytic (FG)

Back 27

muscle fiber that primarily uses anaerobic glycolysis

Front 28

fast oxidative (FO)

Back 28

intermediate muscle fiber that is between slow oxidative and fast glycolytic fibers

Front 29

fibrosis

Back 29

replacement of muscle fibers by scar tissue

Front 30

glycolysis

Back 30

anaerobic breakdown of glucose to ATP

Front 31

graded muscle response

Back 31

modification of contraction strength

Front 32

hyperplasia

Back 32

process in which one cell splits to produce new cells

Front 33

hypertonia

Back 33

abnormally high muscle tone

Front 34

hypertrophy

Back 34

addition of structural proteins in muscle fibers

Front 35

hypotonia

Back 35

abnormally low muscle tone caused by the absence of low-level contractions

Front 36

intercalated disc

Back 36

part of the sarcolemma that connects cardiac tissue, and contains gap junctions and desmosomes

Front 37

isometric contraction

Back 37

muscle contraction tht occurs with no change in muscle length

Front 38

isotonic contraction

Back 38

muscle contraction that involves changes in muscle length

Front 39

lactic acid

Back 39

product of anaerobic glycolysis

Front 40

latch-bridges

Back 40

subset of a cross-bridge in which actin and myosin remain locked together

Front 41

latent period

Back 41

the time when a twitch does not produce contraction

Front 42

motor end-plate

Back 42

sarcolemma of muscle fiber at the neuromuscular junction, with receptors for the neurotransmitter acetylcholine

Front 43

motor unit

Back 43

motor neuron and the group of muscle fibers it innervates

Front 44

muscle tension

Back 44

force generated by the contraction of the muscle; tension generated during isotonic contractions and isometric contrations

Front 45

muscle tone

Back 45

low levels of muscle contraction that occur when a muscle is not producing movement

Front 46

myoblast

Back 46

muscle-forming stem cell

Front 47

myofibril

Back 47

long, cylindrical organelle that runs parallel within the muscle fiber and contains the sarcomeres

Front 48

myogram

Back 48

instrument used to measure twitch tension

Front 49

myosin

Back 49

protein that makes up most of the thick cylindrical myofilament within a sarcomere muscle fiber

Front 50

myotube

Back 50

fusion of many myoblast cells

Front 51

neuromuscular junction (NMJ)

Back 51

synapse between the axon terminal of a motor neuron and the section of the membrane of a muscle fiber with receptors for the acetylcholine released by the terminal

Front 52

neurotransmitter

Back 52

signaling chemical released by nerve terminals that bind to and activate receptors on target cells

Front 53

oxygen debt

Back 53

amount of oxygen needed to compensate for ATP produced without oxygen during muscle contraction

Front 54

pacesetter cell

Back 54

cell that triggers action potentials in smooth muscle

Front 55

pericyte

Back 55

stem cell that regenerates smooth muscle cells

Front 56

perimysium

Back 56

connective tissue that bundles skeletal muscle fibers into fascicles within a skeletal muscle

Front 57

power stroke

Back 57

action of myosin pulling actin inward (toward the M line)

Front 58

pyruvic acid

Back 58

product of glycolysis that can be used in aerobic respiration or converted to lactic acid

Front 59

recruitment

Back 59

increase in the number of motor units involved in contraction

Front 60

relaxation phase

Back 60

period after twitch contraction when tension decreases

Front 61

sarcolemma

Back 61

plasma membrane of a skeletal muscle fiber

Front 62

sarcomere

Back 62

longitudinally, repeating functional unit of skeletal muscle, with all of the contractile and associated proteins involved in contraction

Front 63

sarcopenia

Back 63

age-related muscle atrophy

Front 64

sarcoplasm

Back 64

cytoplasm of a muscle cell

Front 65

sarcoplasmic reticulum (SR)

Back 65

specialized smooth ER, which stores, releases, and retrieves Ca++

Front 66

satellite cell

Back 66

stem cell that helps to repair muscle cells

Front 67

skeletal muscle

Back 67

striated, multinucleated muscle that requires signaling from the nervous system to trigger contraction; most skeletal muscles are referred to as voluntrary muscles that move bones and produce movement

Front 68

slow oxidative (SO)

Back 68

muscle fiber that primarily uses aerobic respiration

Front 69

smooth muscle

Back 69

nonstriated, mononucleated muscle in the skin that is associated with hair follicles; assists in moving materials in the walls of internal organs, blood vessels, and internal passageways

Front 70

somites

Back 70

blocks of paraxial mesoderm cells

Front 71

stress-relaxation response

Back 71

relaxation of smooth muscle tissue after being stretched

Front 72

synaptic cleft

Back 72

space between a nerve (axon) terminal and a motor end-plate

Front 73

T-tubule

Back 73

projection of the sarcolemma into the interior of the cell

Front 74

tetanus

Back 74

a continuous fused contraction

Front 75

thick filament

Back 75

the thick myosin strands and their multiple heads projecting from the center of the sarcomere toward, but not all to way to, the Z-discs

Front 76

thin filament

Back 76

thin strands of actin and its troponin-tropomyosin complex projecting from the Z-discs toward the center of the sarcomere

Front 77

treppe

Back 77

stepwise increase in contraction tension

Front 78

triad

Back 78

the grouping of one T-tubule and two terminal cisternae

Front 79

tropomyosin

Back 79

regularoty protein that covers myosin-binding sites to prevent actin from binding to myosin

Front 80

troponin

Back 80

regulatory protein that binds to actin, tropomyosin, and calcium

Front 81

twitch

Back 81

single contraction produced by one action potential

Front 82

varicosity

Back 82

enlargement of neurons that release neurotransmitters into synaptic clefts

Front 83

visceral muscle

Back 83

smooth muscle found in the walls of visceral organs

Front 84

voltage-gated sodium channels

Back 84

membrane proteins that open sodium channels in response to a sufficient voltage change, and initiate and transmit the action potential as Na+ enters through the channel

Front 85

wave summation

Back 85

addition of successive neural stimuli to produce greater contraction