A&p Muscular System

Front 1

Epimysium

Back 1

Sheath of fibrous connective tissue surrounding a muscle

Front 2

Acetylcholinesterase (AChE)

Back 2

Enzyme present at the neuromuscular junction and synapses that degrades acetylcholine and terminates its action.

Front 3

Perimysium

Back 3

Connective tissue that bundles muscle fibers into fascicles.

Front 4

Hernia

Back 4

Abnormal protrusion of an organ or a body part through the containing walls of its cavity.

Front 5

Stressor

Back 5

Any stimulus that directly or indirectly causes the hypothalamus to initiate stress reducing responses, such as the fight or flight response.

Front 6

Origin

Back 6

Attachment of a muscle that remains relatively fixed during muscular contraction

Front 7

Myofilament

Back 7

Filament that contains myofibrils. Of two types: actin and myosin.

Front 8

Resistance exercise

Back 8

High intensity exercise in which the muscles are pitted against high resistance or immovable forces and, as a result, muscle cells increase in size.

Front 9

Muscle fiber

Back 9

A muscle cell.

Front 10

Muscular system

Back 10

The organ system consisting of the skeletal muscles of the body and their connective tissue attachments.

Front 11

Creatine kinase

Back 11

Enzyme that catalyzes the transfer of phosphate from creatine phosphate to ADP, forming creatine and ATP; important in muscle contraction.

Front 12

Sarcolemma

Back 12

The plasma membrane of a muscle fiber.

Front 13

Sarcomere

Back 13

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

Front 14

Isometric contraction

Back 14

Contraction which the muscle does not shorten but its internal tension increases.

Front 15

Anaerobic glycolysis

Back 15

Energy yielding conversion of glucose to lactic acid in various tissues, notably muscle, when sufficient oxygen is not available.

Front 16

Aerobic endurance

Back 16

The length of time a muscle can continue to contact using aerobic pathways.

Front 17

Graded muscle responses

Back 17

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

Front 18

Anaerobic threshold

Back 18

The point at which muscle metabolism converts to anaerobic glycolysis.

Front 19

Oxidative phosphorylation

Back 19

Process of ATP synthesis during which an inorganic phosphate group is attached to ADP; occurs via electron transport chain within the mitochondria.

Front 20

Actin

Back 20

A contractile protein of muscle.

Front 21

Fascicle

Back 21

Bundle of nerve or muscle fibers bound together by connective tissue.

Front 22

Muscle tension

Back 22

The force exerted by a contacting muscle on some object.

Front 23

Lever system

Back 23

Consists of a lever (bone), effort (muscle action), resistance (weight of object to be moved), and fulcrum (joint).

Front 24

Myofibril

Back 24

Rodlike bundle of contractile filaments found in muscle fibers (cells).

Front 25

Aerobic

Back 25

Oxygen requiring

Front 26

Muscular dystrophy

Back 26

A group of inherited muscle destroying diseases.

Front 27

Smooth muscle

Back 27

Spindle shaped cells with one centrally located nucleus and no externally visitable striations. Found mainly in the walls of hollow organs.

Front 28

Glycolysis

Back 28

Breakdown of glucose to pyruvic acid-- an anaerobic process.

Front 29

Anaerobic

Back 29

Not requiring oxygen

Front 30

Fixator

Back 30

Muscle that immobilizes one out more bones, allowing other muscles to act from a stable base.

Front 31

Cardiac muscle

Back 31

Specialized muscle of the heart.

Front 32

Fulcrum

Back 32

The fixed point on which a lever moves when a force is applied.

Front 33

Visceral muscle

Back 33

Type of smooth muscle; its cells rhythmically contact as a unit and are electrically coupled by gap junctions, and often exhibit spontaneous action potential. Also called unitary smooth muscle

Front 34

Myoblasts

Back 34

Embryonic mesoderm cells from which all muscle fibers develop.

Front 35

Insertion

Back 35

Moveable attachment of a muscle.

Front 36

Excessive postexercise oxygen consumption (EPOC)

Back 36

The volume of oxygen required after exercise to replenish stores of O2, ATP, creatine phosphate, and glycogen and oxidize the lactic acid formed during exercise. Also called oxygen debt.

Front 37

Synaptic vesicles

Back 37

Small membranous sacs containing neurotransmitter.

Front 38

Myogram

Back 38

A graphic recording of mechanical contractile activity produced by an apparatus that measures muscle contraction.

Front 39

Sarcoplasmic reticulum (SR)

Back 39

Specialized endoplasmic reticulum of muscle cells.

Front 40

Action potential

Back 40

A large transient depolarization event, including polarity reversal, that is conducted along the membrane of a muscle cell or a nerve fiber.

Front 41

Voluntary muscle

Back 41

Muscle under strict nervous control; skeletal muscle.

Front 42

Muscle tone

Back 42

Low levels of contractile activity in relaxed muscle; keeps the muscle healthy and ready to act.

Front 43

Threshold stimulus

Back 43

Weakest stimulus capable of producing a response in an excitable tissue

Front 44

Sarcoplasm

Back 44

The cytoplasm of a muscle fiber.

Front 45

Excitability (responsiveness)

Back 45

Ability to respond to stimuli.

Front 46

Skeletal muscle

Back 46

Muscle composed of cylindrical multinucleate cells with obvious striations; the muscle attached to the body skeleton; voluntary muscle.

Front 47

Synaptic cleft

Back 47

Fluid-filled space at a synapse.

Front 48

Isotonic contraction

Back 48

Contraction in which muscle tension remains constant at a given load, and the muscle shortens.

Front 49

Aponeurosis

Back 49

Fibrous or membranous sheet connecting a muscle and the part it moves.

Front 50

Muscle twitch

Back 50

The response of a muscle to a single brief threshold stimulus.

Front 51

Tendon

Back 51

Cord of dense regular connective tissue attaching muscle to bone.

Front 52

Vas

Back 52

A duct or vessel.

Front 53

Contractility

Back 53

Muscle cell's ability to move by shortening.

Front 54

Myoglobin

Back 54

Oxygen binding pigment in muscle.

Front 55

Adduct

Back 55

To move toward the midline of the body.

Front 56

Excitation-contraction (E-C) coupling

Back 56

Sequence of events by which transmission of an action potential along the sarcolemma leads to the sliding of myofilaments.

Front 57

Varicosities

Back 57

Knoblike swellings of certain autonomic axons containing mitochondria and synaptic vesicles.

Front 58

Innervation

Back 58

Supply of nerves to a body part.

Front 59

Motor unit

Back 59

A motor neuron and all the muscle cells it stimulates.

Front 60

Mechanical disadvantage (speed lever)

Back 60

Condition that occurs when the load is far from the fulcrum and the effort is applied near the fulcrum; the effort applied must be greater than the load to be moved.

Front 61

Neurotransmitter

Back 61

Chemical messenger released by neurons that may, upon binding to receptors of neurons or effector cells, simulate or inhibit those neurons or effector cells.

Front 62

Acetylcholine (ACh)

Back 62

Chemical transmitter substance released by some nerve endings.

Front 63

Prime mover

Back 63

Muscle that bares the major responsibility for effecting a particular movement; an agonist.

Front 64

T tubule (transverse tubule)

Back 64

Extension of the muscle cell plasma membrane that protrudes deeply into the muscle cell.

Front 65

Peristalsis

Back 65

Progressive, wavelike contractions that move foodstuffs through the alimentary tube organs (or that move other substances through other hollow body organs).

Front 66

Agonist

Back 66

Muscles that bears the major responsibility for effecting a particular movement; a prime mover.

Front 67

Relative refractory period

Back 67

Follows the absolute refractory period; interval when a threshold for action potential stimulation is markedly elevated.

Front 68

Neuromuscular junction (motor end plate)

Back 68

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

Front 69

Aerobic respiration

Back 69

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 70

Mechanical advantage (power lever)

Back 70

Condition that occurs when the load is close to the fulcrum and the other is applied far from the fulcrum; allows a small effort exerted over a relatively large distance to move a large load over a small distance.

Front 71

Tetanus

Back 71

A smooth, sustained muscle contraction resulting from high frequency stimulation; an infectious disease caused by an anaerobic bacterium.

Front 72

Antagonist

Back 72

Muscles that reverses, or opposes, the action of another muscle. Hormone that opposes the action of another hormone.

Front 73

Contraction

Back 73

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

Front 74

Synergist

Back 74

Muscle that aids the action of a prime mover by effecting the same movement or by stabilizing joints across which the prime mover acts, preventing undesirable movement. Hormone that amplifies the effect of another hormone at a target cell.

Front 75

Skeletal muscle

Back 75

Muscle composed of cylindrical multinucleate cells with obvious striations; the muscle attached to the body's skeleton; voluntary muscle.

Front 76

Myosin

Back 76

One of the principal contractile proteins found in muscle.

Front 77

Endomysium

Back 77

Thin connective tissue surrounding each muscle cell.

Front 78

Polypeptide

Back 78

A chain of amino acids.

Front 79

Diaphragm

Back 79

Any partition or wall separating one area from another; the muscle that separates the thoracic cavity from the lower abdominopelvic cavity.

Front 80

Latent period

Back 80

Period of time between stimulation and the onset of muscle contraction.

Front 81

Creatine phosphate (CP)

Back 81

Compound that serves as an alternative energy source for muscle tissue.

Front 82

Lactic acid

Back 82

Product of anaerobic metabolism, especially in muscle.