Compared to tissue fluid, the osmotic pressure of blood is typically ___; thus water moves into the ___

Correct Answer: A

Rationale: Blood’s osmotic pressure (oncotic, ~25 mmHg) is greater than tissue fluid’s due to plasma proteins (A), drawing water back into capillaries at the venous end. B, C, D mismatch osmosis direction.

Correct Answer: B

Rationale: The descending aorta (abdominal) ends by branching into the common iliac arteries (B) supplying the pelvis and legs. Celiac (A), renal (C), and mesenteric (D) branch earlier.

Correct Answer: D

Rationale: The myocardium (D) is the thickest layer, comprising the heart’s muscular wall (~2-15 mm depending on chamber). Epicardium (A) is a thin serous layer, endocardium (B) is endothelium, and pericardium (C) is the outer sac.

Correct Answer: B

Rationale: Bradycardia (<60 bpm) is common in athletes (B) due to high vagal tone and cardiovascular fitness. Pilots (A), surgeons (C), and chess players (D) don’t typically exhibit it.

Correct Answer: C

Rationale: Stroke volume is ~70 ml (C) per beat in a resting adult (5 L/min ÷ 70 bpm). 30 ml (A) is too low, 130 ml (B) too high, and 5 L (D) is cardiac output.