- A Axon itself, where the cytoplasm is interrupted
- B Myelin sheath exposing the axon membrane
- C Cell body, where the nucleus and organelles are located
- D Dendrites, where incoming signals are received
Correct answer: B. Myelin sheath exposing the axon membrane
Explanation: Nodes of Ranvier: gaps in the myelin sheath where the axon membrane is exposed. Action potentials regenerate here, enabling saltatory conduction.
Concept context
Brain, spinal cord, neurons, reflex arcs, and sense organs.