Question

When neurons are resting what is the axonal membrane impermeable to?

Answer 1

Neurons:

1. Neurons are the fundamental units of the nervous system.
2. Each neuron in the brain contains a thread-like structure attached to a nerve cell known as an axon which is made up of myelin sheath.
3. Axons carry the electrical impulses from one neuron to another neuron.
4. The membranes of neurons are in a polarized state.
5. The membranes have different types of ion channels that are selectively permeable to various ions.

When neurons are resting:

1. When neurons are at a resting state the neurons do not conduct any impulses.
2. The fluids outside the axon have a low concentration of potassium ions and a high concentration of sodium ions.
3. The axoplasm inside the axon has a high concentration of potassium ions and a low concentration of sodium ions.
4. Thus, the outer surface of the axonal membrane is positively charged and the outer membrane s negatively charged.
5. During the resting of neurons, the axonal membrane is more permeable to potassium ions and nearly impermeable to sodium ions.