水、电解质乱 (二)钠的生理功能 ( Functions of sodium in body) 12 Maintaining the osmolality of the ECF; Effect to water distribution between the ICF and ECF. 3. Participates in acid-base balance 4. Maintaining the normal neuromuscular irritability participates in action potential formation（二）钠的生理功能 (Functions of sodium in body) 1．Maintaining the osmolality of the ECF; 4．Maintaining the normal neuromuscular irritability， participates in action potential formation. 3．Participates in acid-base balance; 2．Effect to water distribution between the ICF and ECF; 水、电解质紊乱