EXAM 3

Question 1

what is reverse muscle action

Answer 1

when origin moves towards insertion

Question 2

describe a first class lever

Answer 2

Effort –> Fulcrum –> Load like a teeter totter

Question 3

example of a first class lever

Answer 3

Neck muscle –> atlas –> skull

Question 4

describe a second class lever

Answer 4

Fulcrum –> Load –> Effort wheelbarrow

Question 5

example of a second class lever

Answer 5

metatarsals, body weight, calf muscles

Question 6

describe a third class lever

Answer 6

Force –> Effort –> Load

Question 7

example of third class lever

Answer 7

elbow joint –> biceps muscle –> weight in hand

Question 8

what is the name of the outer covering of the muscle

Answer 8

epimysium

Question 9

what covers the fascicles of the muscle

Answer 9

perimysium

Question 10

what covers muscle fibers

Answer 10

endomysium

Question 11

are skeletal muscles mono or multi nucleate

Answer 11

multinucleate

Question 12

how do muscles fibers grow by hypertrophy or hyperplasia

Answer 12

hypertrophy

Question 13

what is the sarcoplasm

Answer 13

cytoplasm of skeletal muscle cell

Question 14

what is the sarcolemma

Answer 14

cell membrane of muscle cell

Question 15

what is the sarcoplasmic reticulum

Answer 15

equivalent of smooth er in muscle cell

Question 16

what is the myofibril

Answer 16

fiber that contains sarcomere

Question 17

what is the functional unit of a muscle cell

Answer 17

sarcomere

Question 18

what are t tubules

Answer 18

high ways where the action potential travels through

Question 19

One sarcomere goes from ___ to ___

Answer 19

z-disk to z-disk

Question 20

what does the A band comprise of

Answer 20

actin + myosin

Question 21

what does the I band consist of

Answer 21

z disc to mysosin, only actin

Question 22

what does the H zone comprise of

Answer 22

only myosin

Question 23

what is the M line

Answer 23

middle line

Question 24

what are the two regulatory proteins

Answer 24

tropomyosin and troponin

Question 25

which regulatory protein binds with calcium

Answer 25

troponin

Question 26

which regulatory protein moves out of the way to expose the myosin binding site

Answer 26

tropomyosin

Question 27

what are the five structural proteins in the sarcomere

Answer 27

titin, dystrophin, nebulin, myomesin, alpha actin

Question 28

describe titin

Answer 28

spans from z disc to m line and stabilizes myosin, gives elasticity

Question 29

describe dystrophin

Answer 29

links actin to the sarcolemma helps transmit tension to tendons

Question 30

describe nebulin

Answer 30

spans length of actin, anchors actin to z disc

Question 31

describe myomesin

Answer 31

found in M- line, hold titin and myosin in position

Question 32

how does the sarcomere change length during contraction

Answer 32

it shortens

Question 33

is the I band reduced, lengthened, or stays the same during contraction

Answer 33

shortened

Question 34

How does the A band change length during contraction

Answer 34

stays the same

Question 35

define excitation

Answer 35

the events that transmit an electrical signal from a motor neuron to a muscle fiber

Question 36

when ATP binds to the myosin heads does this make them detatch or attach

Answer 36

detatch

Question 37

describe relation of a muscle

Answer 37

active Ca transporters remove Ca from sarcoplasm, Ca levels drop and titin brings sarcomere to resting position

Question 38

what are the 3 sources of energy from muscles

Answer 38

creatine phosphate, anaerobic, aerobic respiration

Question 39

how long does the body use creatine phosphate for

Answer 39

10-15 seconds

Question 40

how long does the body use anaerobic respiration

Answer 40

up to 2-3 minutes

Question 41

how long does the body use aerobic respiration

Answer 41

long long time

Question 42

describe SO fibers Type I

Answer 42

called slow because contraction cycle is slower, many mitochondria, produce energy by anaerobic respiration, dont fatigue easy, red in color

Question 43

describe FOG fibers Type IIA

Answer 43

called fast bc contraction cycle is faster, many mitochondria, produce energy by both anaerobic and aerobic respiration,

Question 44

describe FG Type IIX

Answer 44

called fast bc contraction cycle is faster, little mitochondria, energy only from anaerobic respiration

Question 45

what is spatial summation

Answer 45

increasing motor unit recruitment

Question 46

what is temporal summation

Answer 46

increasing the frequency of stimulation

Question 47

define isometric contraction

Answer 47

generates tension but does not shorten

Question 48

define concentric contraction

Answer 48

when the tension generated is sufficient enough to move the load, the muscle shorten

Question 49

define eccentric contraction

Answer 49

as tension decreases, the load exceeds the tension, the muscle lengthens