When you step on a sharp tack and pull your foot away, this movement involves all of the following except
A) the contraction of one set of leg muscles and the relaxation of an antagonistic set of muscles.
B) a polysynaptic spinal reflex.
C) interneurons between sensory and motor neurons in the spinal cord.
D) sensory neurons that synapse directly with motor neurons in the spinal cord.
E) motor input through the dorsal root that synapses with interneurons in the spinal cord.

Question

Quizplus · Accepted Answer

The correct movement involves motor output, not input, through the ventral root of the spinal cord, not the dorsal root which is associated with sensory input.

When You Step on a Sharp Tack and Pull Your