(1) fewer or more (2) more or less The adjacent image depicts the human motor ho
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Question
(1) fewer or more
(2) more or less
The adjacent image depicts the human motor homunculus. Recall that the motor cortex is the portion of the brain that plans and executes voluntary movements. The motor homunculus describes the proportion of motor cortex neurons devoted to a particular part of the body Shoulder Trunk Elbow Hip Ankle Fingers Brow Assume that each motor cortex neuron controls the same number of efferent motor neurons. Therefore the "larger" a body part is on the motor homunculus the more efferent neurons that innervate its muscles. Eyelid/eyeball ?Face Lips Based on the motor homunculus provided, the brow must contain esophagus. Therefore, the muscles of the brow are -a Tongue Esophagus motor units than the capable of fine, delicate movements than the muscles of the esophagusExplanation / Answer
From the given information it is evident that the larger a body part is in the motor homunculus, the more are the efferent neurons that innervate its muscles. Efferent neurons function to carry information from the central nervous system to muscles and organs in the body in order to initiate an action. Therefore, based on the motor homunculus provided, the brow must contain fewer motor units than the esophagus. Therefore, the muscles of the brow are less capable of fine, delicate movements than the muscles of the esophagus.
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