Question

Bulk solution inside an axon is ________ relative to outside.

a. negatively charged (-65 mV)
b. positively charged (+65 mV)
c. slightly positively charged (+10 mV)
d. electrically neutral (0 mV)

Answer 1

The bulk solution inside an axon is negatively charged (-70 mV) relative to the outside. This is known as the resting membrane potential.

Step-by-step explanation:

The bulk solution inside an axon is negatively charged (-70 mV) relative to the outside. This voltage is called the resting membrane potential, and it is caused by differences in the concentrations of ions inside and outside the cell. Specifically, the higher concentration of positively charged sodium ions (Na+) outside the cell compared to the higher concentration of negatively charged potassium ions (K+) inside the cell creates a negative charge.