Question

Changes in K+ ion concentrations are often dangerous. Simply doubling the concentration of K+ in the extracellular fluid, can lead to death. Which of the following choices correctly explains why deviations in K+ concentrations can be lethal? Select one: a. Excess K+ in the ECF diminishes the electrochemical gradient for K+ to leak out of the cell. As fewerk leave the cell, the resting membrane potential become more positive and is more likely to depolarize. b. Excess K+ in the ECF decreases the space available for other ions like Na+ and Ca++. When space is limited. K+ ions bind to Na+ and precipitate out of solutions forming the salt Nak. c. Excess K+ in the ECF increases the electrochemical gradient for K+ to leak out of the cell. As more K+ leave the cell, the resting membrane potential become more negative and is less likely to depolarize. O d. Excess K+ in the ECF completely prevents the moyements of ions in and out of cells. Without ion movement, the cell depolarizes and depolarizes spontaneously

Answer 1

Answer A. Excess K+ in the ECF diminishes the electrochemical gradient for K+ to leak out of the cell. as fewer K+ leave the cell, the resting membrane potential becomes more positive and is more likely to depolarise.
K+ ion is low in the ECF and this leads to negative Resting membrane potential of the cell. Increase in K+ concentration in the ECF leads to decrease in electrochemical gradient. This leads to RMP shifting closer to threshold potential and will lead to easy depolarisation of the cells.