Question

A myelin sheath is a______.

A. large band of neural fibers connecting the two hemispheres of the brain.
B. fatty tissue layer encasing the axon of a nerve cell.
C. bushy extension of a neuron that conducts impulses toward the cell body.
D. nerve network within the brainstem that controls physical arousal.

Answer 1

Answer:B. Fatty tissue layer encasing the axon of a nerve cell

Explanation: Myelin is an insulating layer that forms around a nerves including those of brain and spinal cord,its is made up if protein and fatty substances.The myelin sheath aids in the quick and efficient transfer of electrical impulses along a nerve cells. Damage to it can slow down the impulse,for example multiple sclerosis diseases.