If a solution of high KCI concentration were accidentally ch

If a solution of high KCI concentration were accidentally chronically infused intravenously into an individual over a period of days, thereby raising the plasma [K^+] concentration, how would this affect their neuronal cell physiology? decreased K^+ diffusion across neuronal cell membranes decrease blood volume major disruption of osmolality of plasma reduced excitability of neurons major disruption of Na^+ concentration gradient across neuronal cell membranes

Solution

Answer is: Major disruption of Na⁺ concentration gradient across neuronal cell membranes

Explanation:

Increased extracellular potassium levels result in depolarization of the membrane potentials of cells due to the increase in the equilibrium potential of potassium. This depolarization opens some voltage-gated sodium channels but also increases the inactivation at the same time. Since depolarization due to concentration change is slow, it never generates an action potential by itself; instead, it results in accommodation.

Above a certain level of potassium, the depolarization inactivates sodium channels, opens potassium channels, thus the cells become refractory. This leads to the impairment of neuromuscular, cardiac, and gastrointestinal organ systems. Of most concern is the impairment of cardiac conduction, which can cause ventricular fibrillation, abnormally slow heart rhythms, or asystole.