final review (electrolytes)

Where is potassium primarily located?

Intracellular fluid

What hormone regulates potassium secretion?

Aldosterone.

What happens in hyperkalemia vs. hypokalemia?

Hyperkalemia → easier depolarization, arrhythmias.
Hypokalemia → hyperpolarization, nonresponsiveness

Which hormone increases blood calcium levels?

Parathyroid hormone (PTH).

What role does calcitriol (Vitamin D) play?

Stimulates intestinal absorption of Ca²⁺.

What are symptoms of hypocalcemia?

Muscle spasms, seizures.

Why is Na⁺ outside and K⁺ inside the cell important?

Maintains osmotic balance and resting membrane potential for nerve/muscle function.

Name the three main buffer systems in blood.

Protein, phosphate, bicarbonate/carbonic acid.

How does hypoventilation affect pH?

Causes respiratory acidosis (↑ CO₂, ↓ pH).

How do kidneys respond to acidosis?

Increase H⁺ secretion, reabsorb/generate HCO₃⁻.

What is edema?

Fluid accumulation in interstitial spaces → impaired circulation, ↓ BP.

What triggers thirst reflex?

Hypothalamus sensing ↑ plasma osmolarity.

What causes metabolic acidosis?

Alcohol, diarrhea, kidney failure.

What causes respiratory alkalosis?

Hyperventilation (anxiety, aspirin overdose).

What causes metabolic alkalosis?

Vomiting (loss of HCl), overuse of antacids.

How does diabetes mellitus affect urinary system?

Osmotic diuresis → excessive urination, dehydration; ketoacidosis → metabolic acidosis.

What happens in hyperaldosteronism?

↑ Na⁺ reabsorption (water retention, ↑ BP), ↑ K⁺ secretion (hypokalemia).