Free Physiology and Coordination in Animals Quiz | University Admission Biology Practice

Physiology and Coordination in Animals

Question 1 of 5

Time left: 00:00

The diagram below shows a spinal reflex arc, such as the one that withdraws the hand from a hot object. Six structures are numbered 1 to 6, and the red arrows show the direction of impulses.

Which option correctly identifies the relay neurone and the effector, and predicts the effect of cutting the nerve fibres at structure 2 (the dorsal root region)?

Select one option.

Relay neurone: 3; effector: 6; the hand would not be withdrawn and no pain would be felt in the hand, but the muscle could still be moved voluntarily
Relay neurone: 2; effector: 6; the hand would not be withdrawn and no pain would be felt
Relay neurone: 4; effector: 1; the hand would not be withdrawn and the muscle would be permanently paralysed
Relay neurone: 3; effector: 5; pain would be felt, but the hand would not be withdrawn
Relay neurone: 3; effector: 6; the hand would still be withdrawn, but no pain would be felt

You have used 0 of 1 attempt

Next ▶