Human Anatomy, Physiology and Pathophysiology
Human anatomy, physiology and pathophysiology test organ structure, normal function and common disease mechanisms. Questions often link a system to a clinical sign or drug effect.
Core rules
- Homeostasis keeps pH, temperature, electrolytes and blood pressure within range. The SA node normally sets heart rate; cardiac output is heart rate × stroke volume.
- The nephron filters plasma at the glomerulus; GFR depends on filtration pressure and surface area. The respiratory system exchanges oxygen and carbon dioxide; the kidney and lungs regulate acid-base balance.
- Pathophysiology includes inflammation, thrombosis, diabetes mellitus, hypertension and neoplasia. Type 1 diabetes is insulin deficiency; type 2 involves insulin resistance and relative deficiency.
Worked example
A blood pressure of 120/80 mmHg has pulse pressure 120 − 80 = 40 mmHg. Mean arterial pressure is diastolic pressure plus one-third of pulse pressure: 80 + (40/3) ≈ 93 mmHg. MAP matters because it approximates organ perfusion pressure.
Traps
Systolic is the higher value; diastolic is the lower value. Do not confuse respiratory acidosis with metabolic acidosis. Oedema is not simply excess water; colloid osmotic pressure and capillary permeability matter. Normal pH is about 7.35 to 7.45.