Chaptet 1 Strture And Function Of Exercising Muscle

Front 1

Epimysium

Back 1

The outer connective tissue that surrounds an entire muscle holding it together.

Front 2

Perimysium

Back 2

The connective tissue sheath surrounding each muscle fasciculus.

Front 3

fasciculus (fascicle)

Back 3

A small bundle of muscle fibers wrapped in a connective tissue sheath within a muscle.

Front 4

muscle fiber

Back 4

An individual muscle cell.

Front 5

Sarcolemma

Back 5

A muscle fiber's cell membrane, a permeable lipid layer coated by proteins.

Front 6

Endomysium

Back 6

A sheath of connective tissue that covers each muscle fiber. (Incloses capillaries ect outside of the sarcolemma)

Front 7

plasmalemma

Back 7

Plasma membrane, the selectively permeable lipid bilayer coated by proteins that composes the outer layer of a cell.

Front 8

transverse tubules (T-tubules)

Back 8

Extensions of the sarcolemma (plasma membrane) that pass laterally through the muscle fiber, allowing nutrients to be transported and nerve impulses to be transmitted rapidly to individual myofibrils.

Front 9

sarcoplasm

Back 9

The gelatin-like cytoplasm in a muscle fiber.

Front 10

sarcoplasmic reticulum (SR)

Back 10

A longitudinal system of tubules that is associated with the myofibrils and that stores calcium for muscle action.

Front 11

myofibril

Back 11

The contractile element of skeletal muscle.

Front 12

sarcomere

Back 12

The basic functional unit of a myofibril.

Front 13

type I (slow-twitch) fiber

Back 13

A type of muscle fiber that has a high oxidative and a low glycolytic capacity, associated with endurance-type activities.

Front 14

type II (fast-twitch) fiber

Back 14

A type of muscle fiber with a low oxidative capacity and a high glycolytic capacity; associated with speed or power activities.

Front 15

Glycolytic capacity

Back 15

A measure of the maximum rate of conversion of glucose to pyruvate or lactate that can be achieved acutely by a cell.

Front 16

force-velocity relation

Back 16

Muscle force as a function of the speed of contraction, which is the number of total cross-bridges attached at various speeds of contraction.

Front 17

Oxidative Capacity

Back 17

A measure of a muscle's maximal capacity to use oxygen in microlitres of oxygen consumed per gram of muscle per hour.

Front 18

length-tension relation

Back 18

Muscle length and how much force can be generated at this length based upon sarcomete length.

Front 19

excitation–contraction coupling

Back 19

The sequence of events by which a nerve impulse reaches the muscle membrane and. leads to cross-bridge activity and thus muscle contraction

Front 20

dynamic contraction

Back 20

Any muscle action that produces joint movement.

Front 21

concentric contraction

Back 21

Any muscle action that produces muscle shortening.

Front 22

eccentric contraction

Back 22

Any muscle action in which muscle lengthens.

Front 23

static (isometric) contraction

Back 23

Action in which the muscle contracts without moving, generating force.

Front 24

a-motor neuron

Back 24

A neuron innervating extrafusal skeletal muscle fibers.

Front 25

Motor unit

Back 25

A single alpha-motor neuron and all the muscle fibers it innervates.

Front 26

rate coding

Back 26

Refers to the frequency of impulses sent to a muscle.

Front 27

twitch

Back 27

The smallest contractile response of a muscle fiber or a motor unit to a single electrical stimulus.

Front 28

summation

Back 28

A series of three stimuli in rapid sequence, prior to complete relaxation from the first stimulus, can elicit an even greater increase in force or tension.

Front 29

tetanus

Back 29

Highest tension developed by a muscle in response to stimulation of increasing frequency.

Front 30

size principle

Back 30

Principle asserting that the size of the motor neuron dictates the order of motor unit recruitment, with small-sized motor neurons being recruited first.

Front 31

sliding filament theory

Back 31

A theory explaining muscle action: A myosin cross-bridge attaches to an actin filament, and then the power stroke drags the two filaments past one another.

Front 32

actin

Back 32

A thin protein filament that acts with myosin filaments to produce muscle action.

Front 33

Tropomyosin

Back 33

A tube shaped protein that twist around actin strands fitting in the grove between them.

Front 34

Troponin

Back 34

A complex protein attached at regular intervals to actin strands and tropomyosin.

Front 35

nebulin

Back 35

A giant protein that coextends with actin and appears to play a regulatory role in mediating actin and myosin interactions. It stiffens the thin filament and augments cross-bridge interaction in skeletal musclehttps://www.pnas.org/content/115/41/10369

Front 36

myosin

Back 36

About two-thirds of all skeletal muscle protein is _________, the principal protein of the thick filament. Each ______ filament typically is formed by about 200 myosin molecules.

Front 37

adenosine triphosphatase (ATPase)

Back 37

An enzyme which is located on the myosin head, splits the ATP to yield adenosine diphosphate (ADP), inorganic phosphate (Pi), and energy.

Front 38

titin

Back 38

A protein that positions the myosin filament to maintain equal spacing between actin filaments. An array of proteins that stabilize the myosin.

Front 39

cross-bridge

Back 39

Each thick filament contains many such heads, which protrude from the thick filament to form _____________ that interact during muscle contraction with specialized active sites on the thin filaments.

Front 40

power stroke

Back 40

The tilting of the myosin head, caused by a strong intermolecular attraction between the myosin cross-bridge and the myosin head, that causes the actin and myosin filaments to slide across each other.