ch10pt3

Question 1

length of sarcomere is related to how much zone of overlap there is. how much over lap is related to how many ___ ___ can grab on to ___

Answer 1

myosin heads, actin

Question 2

The number of pivoting cross-bridges, the fiber’s resting length at the time of stimulation, and the frequency of stimulation all affect ____ ____

Answer 2

tension production

Question 3

_____ __ _____ between thick and thin fibers and number of pivoting cross bridges affects Length-Tension Relationships

Answer 3

amount of overlap

Question 4

______ ______ produces greatest amount of tension

Answer 4

optimum overlap

Question 5

Too much or too little overlap reduces efficiency because

Answer 5

no room for sarcomere to contract, myosin heads can’t reach active sites on actin (too far away)

Question 6

optimal rest length of sarcomere

Answer 6

2-2.5 micrometers

Question 7

no tension will be produced if sarcomere is <___ or >____ of optimal length

Answer 7

60%, 175%

Question 8

skeletal system limits __________ of muscles

Answer 8

overstretching

Question 9

CNS monitors resting sarcomeres and maintains muscle ____

Answer 9

tone

Question 10

must be reached for action potential to be generated in muscle fiber

Answer 10

threshold voltage

Question 11

at threshold voltage, a single neural stimulus causes a

Answer 11

twitch

Question 12

sustained muscle contractions require

Answer 12

repeated stimuli

Question 13

phases of a twitch (3)

Answer 13

latent period, contraction phase, relaxation phase

Question 14

Muscle has been stimulated, Not yet contracting

Answer 14

latent period

Question 15

The action potential moves through t-tubules, Ca2+ released from SR

Answer 15

latent period

Question 16

Elastic components tensed (_______ Tension)

Answer 16

latent period, Internal

Question 17

Phase which sarcomere shortens, Tension builds to peak (_____ Tension)

Answer 17

contraction phase, External

Question 18

Ca2+ levels fall, Active sites are covered and tension falls to resting levels

Answer 18

relaxation phase

Question 19

The normal range of sarcomere lengths in the body is ___ to ___ percent of the optimal length.

Answer 19

75, 130

Question 20

successive stimulations before the end of relaxation phase. Increases tension in a wave patterns

Answer 20

wave summation / temporal summation

Question 21

Rapid stimulation continues, twitches reach maximum tension, muscle is in sustained fluttering contraction

Answer 21

incomplete tetanus

Question 22

If stimulation frequency is high enough, muscle never begins to relax, and is in continuous contraction (Not a normal physiologic state)

Answer 22

complete tetanus

Question 23

Bacteria Clostridium tetani releases a toxin. CNS cannot inhibit unwanted contractions.

Answer 23

tetanus

Question 24

Results in Spastic Paralysis
“LockJaw”

Answer 24

tetanus

Question 25

Bacteria Clostridium botulinum releases a toxin. _______ toxin blocks Ach release. Results in flaccid paralysis.

Answer 25

botulism

Question 26

types of contraction (2)

Answer 26

isotonic and isometric

Question 27

Skeletal muscle changes length resulting in motion

Answer 27

isotonic contraction

Question 28

if muscle tension is greater than load (resistance), muscle will ______, causing _______ contraction (flexion)

Answer 28

shorten, concentric

Question 29

if muscle tension is less than load (resistance), muscle will ______, causing _______ contraction (extension)

Answer 29

lengthen, eccentric

Question 30

Skeletal muscle develops tension equaling the load / resistance. Muscle does not change length.

Answer 30

isometric contraction

Question 31

Used to maintain position / posture

Answer 31

isometric contraction

Question 32

The pull of elastic elements (tendons, elastic components of sarcomere), expands the sarcomeres to resting/relaxed length.

Answer 32

elastic forces

Question 33

to move body to original position, ______ ______ contract

Answer 33

opposing muscles

Question 34

skeletal muscles exist in _______ pairs. one contracts, other lengthens, visa versa

Answer 34

opposing

Question 35

Can take the place of opposing muscle contraction to return a muscle to its resting state

Answer 35

gravity

Question 36

Provides Energy For Muscle Contraction. Sustained muscle contraction uses a lot of this energy. Myosin heads need this to be loaded into their cocked position.

Answer 36

ATP

Question 37

myosin heads hydrolyze ATP to

Answer 37

ADP + Phosphate

Question 38

Muscles store enough energy to start contraction. Muscle fibers must manufacture more ATP for

Answer 38

future contractions

Question 39

active energy molecule used by muscles

Answer 39

adenosine triphosphate (ATP)

Question 40

storage molecule for excess energy in resting muscle

Answer 40

creatine phosphate (CP)

Question 41

using this enzyme ADP is recycled back into ATP by taking a phosphate from creatine phosphate (CP)

Answer 41

creatine kinase (CK)

Question 42

this enzyme makes an ATP by taking a phosphate from ADP

Answer 42

myokinase

Question 43

new ATP can be generated by

Answer 43

Aerobic metabolism or anaerobic glycolysis

Question 44

Is the primary energy source of resting muscles and moderately active muscles. Breaks down fatty acids or pyruvic acid.

Answer 44

aerobic metabolism

Question 45

Is the primary energy source for peak muscular activity. Produces two ATP molecules per molecule of glucose. Breaks down glucose stored in skeletal muscles (glycogen). Produces Lactic Acid.

Answer 45

anaerobic glycolysis

Question 46

When muscles can no longer perform a required activity, they are

Answer 46

fatigued

Question 47

Depletion of metabolic reserves, low pH (lactic acid buildup), muscle exhaustion and pain.

Answer 47

results of Muscle Fatigue

Question 48

in the ____ _____, the removal and recycling of lactic acid is done by the _____

Answer 48

Cori Cycle, liver

Question 49

Liver converts lactate to ______, then pyruvate to _____ (gluconeogenesis)

Answer 49

pyruvate, glucose

Question 50

______ is released to recharge muscle glycogen reserves.

Answer 50

glucose