Which of the Following Statements About the Chloride Shift Is

Question

Which of the following statements about the chloride shift is false?
A) It involves a movement of chloride ion into RBCs.
B) It depends on the chloride-bicarbonate countertransporter.
C) It involves a movement of bicarbonate ions into the plasma.
D) It is driven by a rise in PCO2.
E) It causes RBCs to swell.

Accepted Answer

The chloride shift actually causes RBCs to shrink, not swell. During the chloride shift, chloride ions move into RBCs in exchange for bicarbonate ions moving out. This occurs in response to a rise in PCO2 (as occurs in metabolically active tissues) and helps to maintain the balance of pH and electrolytes between RBCs and plasma.