In the motor and sensory homunculi, each body part is shown next to the area of cerebral cortex devoted to it. Which statement best describes what these homunculi represent?
A) The homunculi map out the dermatomes of the body.
B) The relative size of the body parts corresponds to the ascending and descending tracts that control that body part.
C) The homunculi are open to interpretation by neurologists, based upon his or her area of specialty.
D) The relative size of the body part represents the relative size of the cortical area devoted to that body part.
E) The relative size of the body part distinguishes which part is primarily on the right side of the brain versus the left.

Question

Quizplus · Accepted Answer

The homunculi illustrate the concept of cortical magnification, where the size of the body part on the homunculus corresponds to the amount of cortical area devoted to it, not its physical size. This explains why areas with finer sensory or motor control, like the hands and face, appear disproportionately large.

In the Motor and Sensory Homunculi, Each Body Part Is