AN5.1-8 | General features of the cardiovascular system — Gate Quiz

Correct. Elastic arteries (aorta, major branches) stretch during systole and recoil during diastole, maintaining diastolic pressure — the Windkessel effect.

Elastic arteries have a media rich in elastic lamellae that allows them to stretch during systole and recoil during diastole, maintaining diastolic flow.

Correct. A portal system is defined by a vein that begins in one capillary bed and ends in another (two capillary beds in series), rather than draining directly into systemic veins.

A portal system (hepatic or hypophyseal) consists of a vein that connects two capillary beds in series — nutrients absorbed in the gut go directly to the liver before reaching systemic circulation.

Correct. Oesophageal varices result from the anastomosis between the left gastric vein (portal territory) and oesophageal tributaries of the azygos vein (systemic territory) in the lower oesophageal wall.

Oesophageal varices = left gastric vein (portal) ↔ oesophageal branches of azygos (systemic). Raised portal pressure engorges this anastomosis.

Correct. The ductus arteriosus connects the pulmonary trunk to the descending aorta, diverting blood away from the non-functioning fetal lungs.

The ductus arteriosus connects the pulmonary trunk to the aorta. At birth it closes (rising pO₂ + falling prostaglandins) to become the ligamentum arteriosum.

Correct. Indomethacin (a COX inhibitor) closes the PDA by inhibiting prostaglandin E2 synthesis — prostaglandins keep the duct open.

Indomethacin (or ibuprofen) inhibits prostaglandin synthesis, promoting ductal closure. Prostaglandin E1 is used to KEEP a duct open in duct-dependent congenital heart lesions.

Correct. The thoracic duct drains into the left venous angle — the junction of the left internal jugular vein and left subclavian vein (forming the left brachiocephalic vein).

The thoracic duct empties into the left venous angle (junction of left internal jugular + left subclavian vein = left brachiocephalic vein).

Correct. Central retinal artery occlusion (CRAO): the retinal artery is a true end artery. Embolism (from AF) causes sudden painless monocular blindness. The cherry red spot occurs because the fovea receives a residual supply from the choroidal circulation visible through the thin foveal tissue.

CRAO = sudden painless monocular vision loss + cherry red spot. The central retinal artery is a true end artery; an embolus from AF causes immediate infarction.

Correct. Oxygenated blood from the umbilical vein → ductus venosus → IVC → RA, where the Eustachian valve (crista dividens) preferentially directs this well-oxygenated stream through the foramen ovale → LA → LV → aortic arch → brain and coronary arteries.

The Eustachian valve at the IVC-RA junction directs the well-oxygenated stream (from the umbilical vein) through the foramen ovale to the left side and hence to the brain and coronary arteries.

Correct. Collateral vessels take time to enlarge (arteriogenesis). Slow progressive occlusion allows months to years for collaterals to develop, whereas acute occlusion leaves insufficient time.

Collateral circulation requires time to develop (arteriogenesis). Slow, progressive occlusion allows adequate collateral formation. Acute occlusion does not allow this adaptation.

Correct. Axillary lymph node dissection disrupts the lymphatic drainage of the arm → lymphoedema. This is the most common cause of upper limb lymphoedema in women in India.

Axillary lymph node dissection removes the lymph nodes that drain the arm. Disruption of lymphatics → protein-rich interstitial fluid accumulates → lymphoedema.