Question

You have accidentally stepped on a painful stimulus while walking in the park barefoot and this has activated reflex circuits in your spinal cord. During the reflex

Group of answer choices

the extensor muscles in both legs contract

the extensor and flexor muscles in the wounded leg both contract

the extensor and flexor muscles in both legs contract

the extensor muscle in the wounded leg relaxes, and the flexor muscle in the wounded leg contracts

the painful stimulus enters the spinal cord via the ventral horn

Answer 1

This type of reflex is called withdrawal reflex. This is a polysynaptic reflex. In this Reflex, the wounded leg undergo Flexion and opposite leg undergo extension. This is because that in the wounded leg, there is relaxation of extensors and contraction of flexors, hence flexion. In opposite leg, there is contraction of extensors and relaxation of flexors, hence extension. This occurs to maintain the posture and the balance. Option D is correct.

The pain sensations are taken by nerves A delta and C fibres which enter the spinal cord via DORSAL HORN, not ventral horn. therefore Option e is incorrect.

Only option D is correct.