A&P 1 exam 3 (part 1)

single motor neuron and all of the muscle fibers it innervates

the basic and smallest unit of skeletal muscle contraction

if control is important, you want motor units to be

if control is not important, you want motor units to be ?

motor units depend on?

low intervation ratio?

high intervation ratio?

is control important in low intervation or high intervation ratio?

high intervation ratios give you

where are motor units found with low intervation?

example of high innervation?

in high innervation you do not need?

what does brain control?

responsible for contracting motor units

2 types of muscle contraction

same force

in isotonic contraction, what happens to the muscle fibers?

same length

what happens to muscle fibers in isometric contraction?

moveable force? immoveable force?

generating a force depending on strength and resistance

what happens when there is a combination of isotonic and isometric contractions?

what is the only thing a muscle fiber can do?

when a muscle receives a nervous impulse what happens?

what can only be initiated with a nervous impulse?

all or none response (invariant)

how does the twitch response length of time vary?

different muscles have a different length of ?

shortest twitch response?

longest twitch response?

where is a short twitch response found?

where is a long twitch respond found?

twitch response happens at what level?

time it takes when neuron arrives at motor unit to when contraction actually occurs

what is a muscle twitch initiated by?

minimum stimulus strength

is required stimulus is above this, it will generate twitch response

if required stimulus is below this, it will not generate a twitch response

if you see a twitch, then is was atleast ____ and will always get the same response and amount

do muscle fibers twitch at organ level?

contraction of whole muscles and is variable

the force of organ level contraction depends on?

min force ?

max force organ level contraction?

in organ level contraction, the CNS determines?

what is variation based on with organ level contraction?

where does recruitment take place?

don't change twitch, but use multiple and overlapping twitches to get the job done

high enough to arrive again before other twitch relaxes

partial twitch fusion where things partially overlap

complete twitch fusion

increase frequency more and stimulus arrive during contraction phase of previous twitch

during what is there no relaxation because the frequency is high enough

this only works for a short period of time

increase duration of contraction by twitch fusion

motor unit stays in ____ until you stop stimulating is or if you run out of energy

twitches get greater and greater

common result of twitch fusion but doesn't always occur

when happens with a higher twitch?

during summation, when a twitch hits the point where it levels off, the sarcomere is?

only works for seconds?

made up of motor units and prolongs partial contraction

tonus helps to

what only works for partial contraction

contraction requires?

during contraction ATP must be synthesized as fast as?

problem with ATP during contractions?

transfer PCr to ADP, which then goes to ATP?  this happens during?

muscle fiber types?

red fibers rely on?

have a slow twitch, oxidative and darker in color

have a fast twitch, powerful, glycolytic and lighter in color

white fibers contraction?

how is the proportion of red vs white fibers determined?

red vs white fibers use muscle function? when

red vs white fibers use genetics when?

sprinters have high proportion of what type of fibers?

marathon runners have high proportion of what type of fibers?