TEST 1

Question 1

ACTIN

Answer 1

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

Question 2

ACTION POTENTIAL

Answer 2

A rapid and substantial depolarization of the membrane of a neuron or muscle cell that is conducted through the cell.

Question 3

ADENOSINE TRIPHOSPHATASE (ATPHASE)

Answer 3

An enzyme that splits the last phosphate group off ATP, releasing a large amount of energy and reducing the ATP to ADP and P.

Question 4

ADENOSINE TRIPHOSPHATE (ATP)

Answer 4

A high energy phosphate compound from which the body derives its energy.

Question 5

a-MOTOR NEURON

Answer 5

Responsible for initiating muscle contraction

Question 6

CACHEXIA

Answer 6

A loss of body weight (wasting) accompanied by muscle atrophy, weakness, and fatigue

Question 7

CONCENTRIC CONTRACTION

Answer 7

Muscle shortening

Question 8

DYNAMIC CONTRACTION

Answer 8

Any muscle action that produces joint movement

Question 9

ENDOMYSIUM

Answer 9

A sheath of connective tissue that covers each muscle fiber

Question 10

EPIMYSIUM

Answer 10

The outer connective tissue that surround an entire muscle, holding it together

Question 11

EXCITATION-CONTRACTION COUPLING

Answer 11

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

Question 12

FASCICLE (FASCICULUS)

Answer 12

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

Question 13

MOTOR UNIT

Answer 13

The motor nerve and the group of muscle fibers it innervates

Question 14

MUSCLE FIBER

Answer 14

An individual muscle cell

Question 15

MUSCULOSKELETAL SYSTEM

Answer 15

Body system composed of the skeleton and skeletal muscles that allows, supports, and helps control human movement.

Question 16

MYOFIBRIL

Answer 16

The contractile element of skeletal muscle

Question 17

MYOSIN

Answer 17

One of the proteins that form filaments that produce muscle action

Question 18

MYOSIN CROSS-BRIDGE

Answer 18

The protruding part of a myosin filaments. It includes the myosin head, which binds to an active site on an actin filament to produce a power stroke that causes the filaments to slide across each other.

Question 19

NEBULIN

Answer 19

A giant protein that coextends with actin and appears to play a regulatory role in mediating actin and myosin interactions.

Question 20

PERIMYSIUM

Answer 20

The connective tissue sheath surrounding each muscle fascicles

Question 21

PLASMALEMMA

Answer 21

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

Question 22

POWER STROKE

Answer 22

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.

Question 23

PRINCIPLE OF ORDERLY RECRUITMENT

Answer 23

Motor units within a given muscle appear to be ranked according to size of motor neuron

Question 24

RATE CODING

Answer 24

(AKA Frequency Coding) Frequency of impulses sent to a muscle. Force generated through number of muscle fibers/rate of impulses sent.

Question 25

SORCOMERE

Answer 25

Basic functional unit of myofibril

Question 26

SARCOLEMMA

Answer 26

Muscle fiber's cell membrane

Question 27

SARCOPLASM

Answer 27

Gelatin-like cytoplasm in a muscle fiber

Question 28

SARCOPLASMIC RETICULUM (SR)

Answer 28

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

Question 29

SATELLITE CELLS

Answer 29

Immature cells that can develop intro mature cell types, such as myoblasts.

Question 30

SINGLE-FIBER CONTACTILE VELOCITY (Vo)

Answer 30

The rate at which an individual muscle cell can shorten and develop tension

Question 31

SIZE PRINCIPLE

Answer 31

(Motor unit recruitment) Small -sized motor units being recruited first.

Question 32

SLIDING FILAMENT THEORY

Answer 32

(Muscle action) Myosin cross bridge attaches to an actin filaments, then power stroke drags the 2 filaments past each other

Question 33

STATIC (ISOMETRIC) CONTRACTION

Answer 33

Muscle contracts without moving, generating force while its length remains the same.

Question 34

SUMMATION

Answer 34

Summing of all individual changes in a neuron's membrane potential

Question 35

TETANUS

Answer 35

Highest tension developed

Question 36

TITIN

Answer 36

Protein that positions myosin filament to maintain equal spacing b/w actin filaments

Question 37

TRANSVERSE TUBULES (T-TUBULES)

Answer 37

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

Question 38

TROPOMYOSIN

Answer 38

Tube shaped protein that twists around actin strands

Question 39

TROPONIN

Answer 39

Complex protein attached at regular intervals to actin strands and tropomyosin.

Question 40

TWITCH

Answer 40

Smallest contractile response of muscle fiber/motor unit to a single electrical stimulus.

Question 41

TYPE I (SLOW-TWITCH ) FIBER

Answer 41

(ENDURANCE) Type of muscle fiber high oxidative and low glycolytic capacity

Question 42

TYPE II (FAST-TWITCH) FIBER

Answer 42

(POWER) Low oxidative and high glycolytic capacity