Stretch Reflex

Question 1

Knee Jerk Number of synapses

Answer 1

Monosynaptic (by pass the brain for reflex)

Question 2

Normal muscle stretch –>

Answer 2

excitation of Muscle Spindles —>
Stimulate group Ia afferents —>
Stimulation of Alpha motorneuron in the spinal cord —>
Contracation of the muscle (extrafusal fibers) —>
returning to its original length.

Question 3

Group Ia - afferent motorneurons

Answer 3

skeletal muscles

stimulate contraction

Question 4

Knee Jerk Reflex

Answer 4

Tap patellar tendon -->
quad to stretch -->
stimulates afferent fibers -->
activation of alpha motor neurons -->
contraction of quadricep

Question 5

Extrafusal fibers

Answer 5

Skeletal muscles stimulated by ALPHA motorneurons

Question 6

Golgi Tendon Reflex response

Answer 6

Is opposite or inverse of the stretch reflex

“Inhibition of prime mover”

Question 7

What stimulates the golgi tendon organs

Answer 7

active muscle CONTRACTION

Question 8

What group of interneurons?

Answer 8

Group Ib

Inhibitory

Question 9

Ib afferent stimulates

Answer 9

Inhibitory interneuron in spinal cord –>

inhibit alpha - motorneurons and causes RELAXATION of the muscle that was originally contracted

Question 10

Number of synapses in Golgi Tendon

Answer 10

Disynaptic

Question 11

Number of synapses in withdrawal reflex

Answer 11

Polysynaptic

Question 12

Flexor -Withdrawal Response

Answer 12

Ipsilateral FLEXION

Contralateral EXTENSION

Question 13

Flexor Stimulus?

Answer 13

Pain

Somatosensory and pain afferrent fibers elicit withdrawal of the stimulated body part from the noxious stimulus

Question 14

Afterdischarge

Answer 14

Prevents the muscle from relaxing for some time.

Question 15

Knee Jerk stimulus?

Answer 15

Muscle is stretched