A patient with repeated vomiting presents with generalized muscle weakness and low reflexes. Laboratory tests show low serum potassium. Which immediate physiologic explanation best accounts for these symptoms?

• A. The loss of gastric acid with vomiting converts potassium to an inert form that accumulates in the liver causing systemic metabolic failure and muscle fatigue unrelated to membrane potentials.
• B. Low serum potassium directly increases sodium entry into cells thereby improving nerve firing and causing tremors and hyperreflexia rather than weakness.
• C. Loss of body potassium reduces the extracellular potassium concentration, hyperpolarizing muscle and nerve cells and making them less excitable, causing weakness and reduced reflexes.
• D. Vomiting primarily raises intracellular potassium causing membrane depolarization and prolonged muscle contraction rather than weakness.

Answer: (C)