Final answer:
The name of the microscopic fiber leading the cell body that carries the nervous impulse alone in a nerve cell is the axon.
Step-by-step explanation:
The microscopic fiber leading the cell body that carries the nervous impulse alone in a nerve cell is called the axon. The axon is a long, thin extension of the cell body that transmits nerve impulses away from the cell body and toward other cells.
It branches at the end to form multiple axon terminals, which transmit the nerve impulses to other cells, often to the dendrites of other neurons. The myelin sheath, on the other hand, is a lipid layer that covers sections of the axon and acts as an electrical insulator.