ACE Pulmonary Endothelium — FRCA Primary MCQ

Instant feedback + full explanation. One question, done properly.

HardPhysiology - CardiovascularACE Pulmonary EndotheliumFRCA Primary

Which vascular bed is the major site of angiotensin-converting enzyme activity relevant to circulating angiotensin I?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — The pulmonary capillary endothelial surface

The best answer is “The pulmonary capillary endothelial surface”. ACE is widely distributed, but the pulmonary capillary endothelium is its major classic site in the systemic circulation. It converts angiotensin I to angiotensin II and also degrades bradykinin. The entire venous return passes through this vascular bed, explaining its important role in circulating renin–angiotensin processing.

Reference: Royal College of Anaesthetists, Primary FRCA Syllabus 2021: https://www.rcoa.ac.uk/sites/default/files/documents/2026-01/Primary-FRCA-Syllabus.pdf