1) The document discusses body fluids and electrolytes, including total body water content, intracellular fluid, extracellular fluid, and the normal exchange between fluid compartments. 2) Volume deficits (dehydration) and volume excess are described, along with their causes, signs and symptoms, and assessment. Ongoing fluid losses are also discussed. 3) Sodium balance and disorders like hyponatremia and hypernatremia are covered, including definitions, causes, and approaches to determining the type and treating each condition.