In what regions is the surface of the axon exposed to the extracellular fluid?
A) ion channels
B) nodes of Ranvier
C) refractory protuberances
D) axon Hillocks

Question

Quizplus · Accepted Answer

The nodes of Ranvier are the gaps in the myelin sheath where the extracellular fluid can come into contact with the axon. This is important for allowing action potentials to jump from node to node, which increases the speed of neural transmission. A) Ion channels are found all along the axon membrane and allow the selective passage of ions into and out of the cell. C) Refractory protuberances and D) Axon hillocks also refer to structures along the axon, but they are not specifically exposed to the extracellular fluid in the same way that the nodes of Ranvier are.

In What Regions Is the Surface of the Axon Exposed