Final answer:
Chronic nerve compression affects the myelin sheath, which is a critical component for the fast transmission of nerve impulses. Electrons micrographs show the myelin sheath as deep, dark black, indicating the layers of Schwann cell membranes. A bundle of axons in the peripheral nervous system is referred to as a nerve.
Step-by-step explanation:
Chronic nerve compression, or entrapment, primarily affects the myelin sheath component of the nerve. This condition can arise from repetitive motions or holding the body in one position for long periods. The myelin sheath is a protective layer that surrounds the axon of a neuron, aids in the transmission of nerve signals, and enhances the speed of nerve conduction. When this sheath is damaged or compressed over time, nerve signal transmission can be disrupted, possibly leading to symptoms such as numbness, tingling, or weakness.
When examining an electron micrograph of a myelinated nerve fiber, the aspects of the cells that react with the stain and appear deep, dark black are primarily the myelin sheath. This sheath is composed of multiple layers that are the tightly wrapped plasma membranes of Schwann cells in the peripheral nervous system or oligodendrocytes in the central nervous system.
The term that describes a bundle of axons in the peripheral nervous system is nerve. Moreover, the axon is the part of a neuron that transmits an electrical signal to a target cell. When considering the pathway from the central nervous system to the peripheral nervous system, the axon of neuron B, which travels in a nerve to a skeletal muscle cell and forms part of the peripheral nervous system, represents an efferent pathway, as it is carrying signals away from the central nervous system to induce a response in the muscle.