The Muscular System

Front 1

Acetlcholinesterase AChE

Back 1

an enzyme found in the synaptic cleft, bound to the postsynaptic membrane, and in tissue fluids; breaks down and inactivates acetylcholine molecules

Front 2

Achilles Tendon

Back 2

the tendon that attaches the calf muscles to the calcaneus, or heel cone; also called the calcaneal tendon

Front 3

Actin

Back 3

a contractile protein of muscle

Front 4

Action Potential

Back 4

an electrical event occurring when a stimulus of sufficient intensity is applied to a neuron or muscle cell, allowing sodium ions to move into the cell and reverse the polarity

Front 5

Aerobic Respiration

Back 5

respiration in which oxygen is consumed and glucose is broken down entirely; water, carbon dioxide, and large amounts of ATP are the final products

Front 6

Aerobic

Back 6

Requiring oxygen to live or grow

Front 7

Anaerobic

Back 7

not requiring oxygen

Front 8

Antagonists

Back 8

muscles or hormones that act in opposition to an agonist or prime mover

Front 9

Aponeurosis

Back 9

fibrous or membranous sheet connecting a muscle and the part it moves

Front 10

Biceps

Back 10

two-headed, especially applied to certain muscles

Front 11

brevis

Back 11

short

Front 12

Calcaneal Tendon

Back 12

the large tendon that inserts on the calcaneus; tension on the tendon produces extension (plantar flexion) of the foot; also called Achilles tendon

Front 13

Cardiac

Back 13

pertaining to the heart

Front 14

Cholinesterase

Back 14

the enzyme that breaks down and inactivates acetylcholine

Front 15

Contraction

Back 15

to shorten or develop tension, an ability highly developed in muscle cells

Front 16

Creatine Phosphate

Back 16

a high-energy compound in muscle cells; during muscle activity, the phosphate group is donated to ADP, regenerating ATP; also called phosphorycreatine

Front 17

Cross-Bridge

Back 17

a myosin head that projects from the surface of a thick filament and that can bind to an active site of a thin filament in the presence of calcium ions

Front 18

Dorsiflexion

Back 18

the elevation of the superior surface of the foot through flexion at the ankle

Front 19

Endomysium

Back 19

the thin connective tissue surrounding each muscle cell

Front 20

Epimysium

Back 20

the sheath of fibrous connective tissue surrounding a muscle

Front 21

Eversion

Back 21

special movement of the foot achieved by turning of the sole laterally

Front 22

Extension

Back 22

movement that increases the angle of a joint; e.g., straightening of a flexed knee

Front 23

Fascicle

Back 23

a bundle of nerve or muscle fibers bound together by connective tissue

Front 24

Fixators

Back 24

muscles acting to immobilize a joint or a bone; fixes the origin of a muscle so that muscle action can be exerted at the insertion

Front 25

Flaccid

Back 25

soft; flabby, relaxed

Front 26

Hypertrophy

Back 26

an increase in the size of a tissue or organ independent of the body's general growth

Front 27

insertion

Back 27

the movable attachment of a muscle as opposed to its origin

Front 28

Involuntary

Back 28

not under conscious control

Front 29

Isometric

Back 29

of the same length

Front 30

Lactic Acid

Back 30

the product of anaerobic metabolism

Front 31

Latent Period

Back 31

the time between the stimulation of a muscle and the start of the contraction phase

Front 32

Motor Unit

Back 32

all of the muscle cells controlled by a single motor neuron

Front 33

Muscle fibers

Back 33

muscle cells

Front 34

Muscle tone

Back 34

sustained partial contraction of a muscle in response to stretch recptor inputs; keeps the muscle healthy and ready to react

Front 35

Muscle twitch

Back 35

a single rapid contraction of a muscle followed by relaxation

Front 36

Muscle

Back 36

a contractile organ composed of muscle tissue, blood vessels, nerves, connective tissues, and lymphatic vessels

Front 37

Myofibrils

Back 37

contractile organelles found in the cytoplasm of muscle cells

Front 38

Myofilament

Back 38

filaments composing the myofibrils. Of two types actin and myosin

Front 39

Myoglobin

Back 39

an oxygen-binding pigment that is especially common in slow skeletal muscle fibers and cardiac muscle cells

Front 40

Myosin

Back 40

one of the principal contractile proteins found in muscle

Front 41

neuromuscular junction

Back 41

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

Front 42

opposition

Back 42

the action by which the thumb is used to touch the tips of the other fingers on the same hand. This unique action makes the human hand such a fine tool for grasping and manipulating things

Front 43

origin

Back 43

attachment of a muscle that remains relatively fixed during muscular contraction

Front 44

oxygen debt

Back 44

the volume of oxygen required after exercise to oxidize the lactic acid formed during exercise

Front 45

perimysium

Back 45

a connective tissue partition that separates adjacent fascicle in a skeletal muscle

Front 46

prime mover

Back 46

muscle whose contractions are primarily responsible for a particular movement; agonist

Front 47

rectus

Back 47

straight

Front 48

relaxation phase

Back 48

the period after a contraction when the tension in the muscle fiber returns to resting levels

Front 49

sarcolemma

Back 49

the cell membrane of a muscle cell

Front 50

sarcomere

Back 50

the smallest contractile unit of the muscle; extends from one Z disc to the next

Front 51

sarcoplasm

Back 51

the cytoplasm of a muscle cell

Front 52

sciatic nerve

Back 52

a nerve innervating the posteromedial portions of the thigh and leg

Front 53

skeletal muscle tissue

Back 53

a contractile tissue dominated by skeletal muscle fibers characterized as striated, voluntary muscle

Front 54

skeletal muscle

Back 54

muscle composed of cylindrical multinucleate cells with obvious striations; the muscle attached to the body's skelton; also called voluntary muscle

Front 55

sliding filament theory

Back 55

the concept that a sarcomere shortens as the think and thin filaments slide past one another

Front 56

smooth endoplasmic reticulum

Back 56

a membranous organelle in which lipid and carbohydrate synthesis and storage occur

Front 57

supination

Back 57

the outward rotation of the forearm causing plans to face anteriorly

Front 58

synaptic cleft

Back 58

the fluid filled space at a synapse between neurons

Front 59

synergist

Back 59

a muscle that assists a prime mover in performing its primary action

Front 60

synergists

Back 60

muscles cooperating with another muscle or muscle group to produce a desired movement

Front 61

terminal

Back 61

toward the end

Front 62

tentanus

Back 62

the tense, contracted state of a muscle; an infectious disease

Front 63

thick filament

Back 63

a cytoskeletal filament in a skeletal or cardiac muscle cell; composed of myosin, with a core of titin

Front 64

thin filament

Back 64

cytoskeletal filament in a skeletal or cardiac muscle cell; consists of actin, troponin, and tropomyosin

Front 65

trunk

Back 65

the thoracic and abdominopelvic regions; a major arterial branch

Front 66

twist

Back 66

a single stimulus-contraction-relaxation cycle in a skeletal muscle

Front 67

visceral

Back 67

pertaining to the internal part of a structure of the internal organs

Front 68

voluntary muscle

Back 68

muscle under control of the will; skeletal muscle

Front 69

voluntary

Back 69

controlled fy conscious thought processes

Front 70

anaerobic

Back 70

not requiring oxygen

Front 71

aerobic

Back 71

requiring oxygen to live or grow

Front 72

sarcomere

Back 72

the smallest contractile unit of muscle; extends from one Z disc to the next

Front 73

origin

Back 73

attachment of a muscle that remains relatively fixed during muscular contraction

Front 74

insertion

Back 74

the movable attachment of a muscle as opposed to its origin

Front 75

actin

Back 75

a contractile protein of muscle

Front 76

antagonist

Back 76

muscle or hormone that acts in opposition to an agonist or prime mover

Front 77

fixators:

Back 77

muscles acting to immobilize a joint or a bone; fixes the origin of a muscle so that muscle action can be exerted at the insertion

Front 78

involuntary

Back 78

not under conscious control

Front 79

isometric:

Back 79

of the same length

Front 80

lactic acid

Back 80

the product of anaerobic metabolism, especially in muscle

Front 81

latent period

Back 81

the time between the stimulation of a muscle and the start of the contraction phase

Front 82

motor unit

Back 82

all of the muscle cells controlled by a single motor neuron

Front 83

muscle tone:

Back 83

sustained partial contraction of a muscle in response to stretch receptor inputs; keeps the muscle healthy and ready to react

Front 84

muscle twitch

Back 84

a single rapid contraction of a muscle followed by relaxation

Front 85

myosin

Back 85

one of the principal contractile proteins found in muscle

Front 86

oxygen debt

Back 86

the volume of oxygen required after exercise to oxidize the lactic acid formed during exerise

Front 87

prime mover:

Back 87

muscle whose contractions are primarily responsible for a particular movement; agonist

Front 88

relaxation phase

Back 88

the period after a contraction when the tension in the muscle fiber returns to resting levels

Front 89

voluntary muscle

Back 89

muscle under control of the will; skeletal muscle