MEDICAL PHYSIOLOGY

Detailed explanation-1: -To reestablish the appropriate balance of ions, an ATP-driven pump (Na/K-ATPase) induces movement of sodium ions out of the cell and potassium ions into the cell.

Detailed explanation-2: -The principal ions involved in an action potential are sodium and potassium cations; sodium ions enter the cell, and potassium ions leave, restoring equilibrium. Relatively few ions need to cross the membrane for the membrane voltage to change drastically.

Detailed explanation-3: -The sodium-potassium pump is an information processing element in brain computation. Brain neurons can transmit signals using a flow of Na+ and K+ ions, which produce an electrical spike called an action potential (AP) (Hodgkin and Huxley, 1952).

Detailed explanation-4: -They use energy supplied by the cell to actually pump ions in or out of the cell, by force if you will. The best examples are the sodium-potassium pumps on the neuron’s membranes. These pumps push sodium ions out of the cell, and potassium ions (K+) into the cell.

Detailed explanation-5: -Na+ is critical for the action potential in nerve cells. As shown in Figure 2.1, action potentials are repeatedly initiated as the extracellular concentration of Na+ is modified. As the concentration of sodium in the extracellular solution is reduced, the action potentials become smaller.