Neurophysiology - L12

Question 1

Muscle Twitch

Answer 1

One Contractile event

Question 2

Slow Twitch

Answer 2

Red Muscle - small motor neuron, high mitochondria count
lots of metabolism
tonic nerve activity
high resistance to fatigue 
large blood supply

Question 3

Fast Twitch

Answer 3

White muscle 
high rate of contraction 
high glycogen content 
small blood supply
for short bursts

Question 4

Temporal Summation

Answer 4

Used to increase overall contraction. You just get a bigger hump

Question 5

Spatial Summation

Answer 5

How to reduce fatigue. Different frequencies of wave. so you have a continuous contraction of one fiber rests while other fires

Question 6

Contractive muscle spindle

Answer 6

Wraps around the muscle and senses length by it changing its own length

Question 7

Golgi Tendon

Answer 7

Measure stretch and are embedded in muscle to measure tension.

Question 8

I A Fiber

Answer 8

Afferent neuron fiber, wraps around the muscle. connects to nervous system and to the α motor neuron back to same muscle. Activated by stretch

Question 9

Gamma Neuron

Answer 9

innervate polar contractive ends of muscle spindle
activated by contraction.
used to keep the muscle at a good tension for A fiber readings

Question 10

Stretch/myotatic Reflex

Answer 10

fastest synapse in the body.
monosynaptic in to spinal cord
activated by stretch - goes to αMN causes muscle contraction (reflex)

Question 11

αMN

Answer 11

Alpha motor neuron - can receive signal to move from CNS or from reflex (I A fiber)

Question 12

Gamma motor neurons

Answer 12

Seperate system to maintain tension on the spindle when muscle shortens it is important in maintaining 1A activity
what id does is keep tension around the muscle the same so that 1A can run properly and signal to the αMN

Question 13

Compensatory Loading

Answer 13

Sustained contraction. Information should always be transmitted to CNS
Needed gamma motor neuron to signal to the muscle.
brain stops getting 1A signal so sends gamma signal to fix itself and get muscle back to status quo
*The state of muscle length is always sent ot CNS regardless of activity

Question 14

3 Ways to Contract

Answer 14

Direct Path - Active αMN and gamma simultaneously from CNS
Indirect Path - stretch muscle. activate 1A and positive αMN
Gamma Alone - Gamma causes shortens muscle and activate 1A and positive alpha MN reaction

Question 15

Golgi Tendon Organ Reflex aka Inverse myotatic reflex

Answer 15

receptor embedded in tendon
if tension is so high it may injury
The 1B afferent neuron goes thru one interneuron and then another motor neruon to shut down the tension so you dont get hurt

Question 16

Reciprocal Inhibition

Answer 16

In order to move smooth you will have to coordinance movements in one fiber. Stretch reflex.

Ex// contraction of flexer causes relax to extensor
1A fibers can cross talk
Uses inhibitory interneurons to block αMN

Question 17

Withdrawal Reflexes

Answer 17

activate synapse that will either inhibit or contract certain muscles causing recoil.