Question

An example of stretch reflex triggered by passive muscle movement is
A) Tendon reflex
B) Ipsilateral reflex
C) Flexor reflex
D) Patellar reflex

Answer 1

The stretch reflex is the muscle contraction in response to stretch. This kind of reflex is not controlled by the brain. Rather the spinal cord is involved in its control. The stretch reflexes are very important in maintaining posture.

Complete answer:
To answer this question, we must know about the passive muscle movement.
Muscle contraction is the activation of tension within muscle. The muscle contraction leads to movement. This muscle contraction is triggered by various reflexes. Let us discuss the types of reflexes-

Tendon reflex- This type of stretch is generated by a blow upon tendons.
Ipsilateral reflex-The reflex which occurs on the same side of the body where the stimulus is detected.
Flexor reflex- It is a polysynaptic reflex which results in flexor muscle contraction. It incorporates a crossed extension reflex.
Patellar reflex- It is a deep tendon reflex. It is a sudden kicking movement of the lower leg in response to tap on the patellar tendon. Tapping of the patellar ligament stimulates the muscle spindles in the quadriceps. It is a passive muscle movement.

Thus the correct answer is option (D).

Note: Patellar reflex is also called knee-jerk reflex. This reflex is triggered on leaning back which stretches the quadriceps. The Patellar tendon is found at the bottom of the kneecap to the top of tibia. Patella tendon is actually a ligament that connects the patella and tibia.