Muscle Physiology

Question 1

types of muscle tissue

Answer 1

cardiac, smooth, skeletal

Question 2

functions of muscle

Answer 2

produce movement, maintain posture, stabilize joints, create heat as they contract

Question 3

attachment of muscle to moveable bone

Answer 3

insertion

Question 4

attachment of immovable bone or less moveable bone

Answer 4

origin

Question 5

layer of dense irregular connective tissue surrounding entire skeletal muscle

Answer 5

epimysium

Question 6

fibrous layer of connective tissue that separates muscle into small bundles called fascicles

Answer 6

perimysium

Question 7

layer of fine areolar connective tissue surrounding each individual muscle fiber

Answer 7

endomysium

Question 8

cordlike part that attaches a muscle to a bone

Answer 8

tendon

Question 9

muscle that bends a joint

Answer 9

flexor

Question 10

muscle that straightens a joint

Answer 10

extension

Question 11

muscle composed of bundles of

Answer 11

fascicles

Question 12

fascicles composed of bundles of

Answer 12

muscle fibers

Question 13

muscle fibers composed of bundles of

Answer 13

muscle cells

Question 14

plasma membrane of muscle fiber

Answer 14

sarcolemma

Question 15

network of connective tissue that extends throughout the muscular system

Answer 15

fascia

Question 16

cytoplasm of muscle fiber

Answer 16

sarcoplasm (contains glycosomes and myofibrils)

Question 17

contractile organelle of muscle fiber

Answer 17

myofibril

Question 18

cellular organelle, modified endoplasmic reticulum of muscle fiber

Answer 18

sarcoplasmic reticulum (stores calcium)

Question 19

muscle impulse is generated and travels deep into the fiber via

Answer 19

transverse tubule

Question 20

small sections of myofibrils

Answer 20

sarcomeres (from one z disc to another)

Question 21

neuron

Answer 21

motor nerve fiber

Question 22

site where an axon of a motor neuron and muscle fiber meet

Answer 22

neuromuscular junction
(motor end plate)

Question 23

muscle fiber connected to an axon at a

Answer 23

synapses

Question 24

a neurotransmitter released at motor end plates by the axon terminals

Answer 24

Acetylcholine (ACh)

Question 25

breaks down ACh into its building blocks, rendering it inactive

Answer 25

Acetylcholinesterase

Question 26

diffuses of ___ across/into the cell membrane resulting in depolarization

Answer 26

sodium ions (Na+)

Question 27

final chemical messenger and "trigger" for muscle contraction. bonds to troponin

Answer 27

calcium ions (Ca+2)

Question 28

activates synaptic vesicles in axon terminals to fuse with plasma membrane of axon terminal

Answer 28

calcium ions (Ca+2)

Question 29

moves calcium back into sarcoplasmic reticulum at rest

Answer 29

calcium (Ca+2) pump

Question 30

covers binding sites on actin

Answer 30

troponin-tropomyosin complex

Question 31

consist of a motor neuron and all muscle fibers

Answer 31

motor unit

Question 32

minimum strength of stimulation of a muscle fiber required to cause contraction

Answer 32

threshold stimulus

Question 33

contractile response of a single muscle fiber to a single impulse

Answer 33

muscle twitch

Question 34

muscle contracts and changes length

Answer 34

isotonic contraction (concentric: shorten & eccentric: lengthen)

Question 35

muscle contracts but does not change length

Answer 35

isometric contraction

Question 36

provides energy for contraction

Answer 36

ATP

Question 37

sources of ATP

Answer 37

direct phosphorylation, anaerobic pathway, aerobic pathway

Question 38

for muscles to return to pre-exercise state:

Answer 38

oxygen reserve replenished/ lactic acid reconverted to pyruvic acid/ glycogen stores replaced/ ATP and creatine phosphate reserves resynthesized

Question 39

force of contraction depends on number of cross bridges attached, which is affected by 4 factors:

Answer 39

number of muscle fibers stimulated/ relative size of fibers/ frequency of stimulation/ degree of stretch

Question 40

3 types of skeletal muscle fibers

Answer 40

slow oxidative fibers- low intensity movements fast oxidative fibers- medium intensity movements fast glycolytic fibers- short term intense movements

Question 41

increase in size of muscles

Answer 41

hypertrophy

Question 42

decrease in size of muscles

Answer 42

atrophy

Question 43

muscle fibers that are spindle-shaped, 1 nucleus, lack striations, lack t-tubes, lack connective tissue sheaths

Answer 43

smooth muscle

Question 44

neurotransmitters for smooth muscles

Answer 44

Acetylcholine & Norepinephrine

Question 45

other difference between smooth muscle and skeletal muscle

Answer 45

slower to contract and relax maintains a forceful contraction longer can change length without change in tautness

Question 46

2 types of smooth muscle

Answer 46

multi-unit smooth muscle unitary (visceral) smooth muscle

Question 47

multi-unit smooth muscle

Answer 47

function as separate units, (iris of eye, walls of blood vessels), stimulated by neurons & hormones

Question 48

unitary (Visceral) smooth muscles

Answer 48

respond as a unit, sheets of muscle fibers, held together by gap junctions, conduct peristalsis, walls of hollow organs, most common