Question

Which is true about typical resting neurons?

A) They have an equal distribution of ions inside and outside the cell.
B) They maintain a positive charge inside the cell and a negative charge outside.
C) They are highly active in generating action potentials.
D) They lack ion channels.

Answer 1

Typical resting neurons possess a negative charge inside and an unequally distributed concentration of ions, maintained by sodium-potassium pumps and selective ion channels.

Step-by-step explanation:

When considering the typical resting state of neurons, it is true that they maintain a negative charge inside the cell, with a resting membrane potential of approximately -70 millivolts (mV) compared to the outside. This negative charge is due to the unequal distribution of ions across the cell membrane and the selective permeability of ion channels. Specialized proteins known as sodium-potassium pumps actively work to maintain this imbalance by pumping three sodium ions (Na+) out of the neuron for every two potassium ions (K+) it brings in, using one molecule of ATP for each cycle of the pump. Furthermore, there are more potassium leakage channels than sodium leakage channels, allowing potassium to leave the cell more readily than sodium enters, which contributes to the negative charge inside.