A fatty cover over the nerve fibre/axon is called what?

A fatty cover over the nerve fibre/axon is called what?

• A. Insulated
• B. Myelin sheath
• C. Nucleus
• D. Sense organs

Answer: (B)

The fatty covering over a nerve fibre is the myelin sheath. It acts as insulation, preventing the electrical signal from leaking out of the axon and letting impulses travel much faster. In the peripheral nervous system, Schwann cells wrap around the axon to form this lipid-rich layer, with gaps called nodes of Ranvier that enable saltatory conduction—signals jump from node to node, speeding up transmission. The other terms aren’t structures that cover an axon: being “insulated” is just a description, the nucleus is the neuron's control center inside the cell, and sense organs are separate structures that detect stimuli. So the myelin sheath is the correct term.

The fatty covering over a nerve fibre is the myelin sheath. It acts as insulation, preventing the electrical signal from leaking out of the axon and letting impulses travel much faster. In the peripheral nervous system, Schwann cells wrap around the axon to form this lipid-rich layer, with gaps called nodes of Ranvier that enable saltatory conduction—signals jump from node to node, speeding up transmission. The other terms aren’t structures that cover an axon: being “insulated” is just a description, the nucleus is the neuron's control center inside the cell, and sense organs are separate structures that detect stimuli. So the myelin sheath is the correct term.