When a vertebrate animal contracts the flexor muscles of a leg, it relaxes the extensor muscles of the same leg. Sherrington considered this evidence for the existence of ____.
A) spatial summation
B) temporal summation
C) inhibitory messages
D) the delay in transmission at synapses

Question

Quizplus · Accepted Answer

Sherrington's observation of the relaxation of the extensor muscles when the flexor muscles of a leg contract suggests the presence of inhibitory messages. This is because the activation of the flexor muscles likely sends inhibitory messages to the extensor muscles, causing them to relax. This phenomenon is known as reciprocal inhibition.

When a Vertebrate Animal Contracts the Flexor Muscles of a Leg