Question 1
Which part of the neuron insulates and speeds up the transmission of nerve impulses along the axon?
- A. Dendrite
- B. Myelin sheath
- C. Synapse
- D. Cell body
Show answer and rationale
Correct answer: B — Myelin sheath
The myelin sheath is a fatty layer that surrounds the axon of a neuron, providing insulation and speeding up the transmission of nerve impulses. This insulation helps prevent the loss of electrical signals as they travel along the axon, allowing for faster and more efficient communication within the nervous system. Dendrites are branching extensions of a neuron that receive signals from other neurons, the synapse is the junction between two neurons where communication occurs, and the cell body contains the nucleus and organelles of the neuron, but none of these structures provide insulation for the transmission of nerve impulses along the axon.