Review Quiz

Question 1

a motor unit is
a) is a neuron and all the muscle fibers it is connected too
b) contains only one type of muscle fiber
c) receives input from higher brain centres
d) all of the above

Question 2

motor cortex

Answer 2

part of the brain where voluntary contraction originates

Question 3

a motor neuron and all the muscle fibers that are connect to it

Answer 3

motor unit

Question 4

motor neurons

Answer 4

nerve cells that are connected to muscle fibers

Question 5

transverse tubule

Answer 5

indentation of the muscle fiber membrane (sarcolemma)

Question 6

axons

Answer 6

transmits electrical signals from nerves to muscle fibers

Question 7

chemical messenger between axons and muscle fibers

Answer 7

acetylcholine

Question 8

sodium and potassium

Answer 8

these are exchanged across the sarcolemma during contraction

Question 9

sarcoplasmic reticulum

Answer 9

where calcium is stored

Question 10

what are two ways you can increase your force development though how you recruit motor units

Answer 10

recruit more motor units
increase firing frequency

Question 11

what causes force summation

Answer 11

incomplete relaxation of muscle, before another impulse comes (more likely to happen in a slow fibre, because it relaxes slower)

Question 12

what causes tetanus

Answer 12

prolonged contraction of a muscle caused by rapidly repeating stimuli, then results in tetanus

Question 13

______ occurs when a stimulus is delivered to a muscle before it has time to relax. This is caused when more calcium is released from the _________. The calcium will bind to additional _________ and this causes more _______ to be lifted off ________ allowing _______ to form cross-bridges

Answer 13

Summation
Sarcoplasmic reticulum
troponin
tropomysoin
actin
mysoin

Question 14

true or false
a single motor unit can have a mixture of fast witch and slow twitch muscles fibres

Answer 14

false

Question 15

true or false
when an action potential is generated in the axon of a motor neuron, only a portion of muscles fibers innervated by that axon will contact if the action potential isn’t strong enough

Answer 15

false

Question 15

true or false
fats twitch motor units usually have a higher number of muscle fibers compared to slow twitch motor units

Answer 15

true

Question 16

you can use your brain centre to override Golgi tendon organ inhibition of motor neurons

Answer 16

false

Question 17

how can you immediately relieve a muscle cramp?
do you think the muscle spindle is more or less active during a muscle cramp

Answer 17

Stetching relieves cramps,

More activated during a muscle cramp, stretching will fatigue the spinal fiber which can stop firing rates

Question 18

long durations of static stretching can impair subsequent strength/ power performance
true or false

Answer 18

true
If you are fatiguing the spindle, it can impair its activity

Question 19

what activity will be improved by activation of the muscle spindle

Answer 19

ability to jump higher fro a basketball rebound