25% of candidates passed this question.

The examiners consider that an understanding of the pulmonary circulation is core area of the syllabus. In general, the anatomy section was better answered than the physiological features. As well as a description of the gross anatomy of the pulmonary circulation tracking it from the pulmonary valve to the left atrium, some mention of the microscopic anatomy was required (e.g., that the pulmonary arteries are thin walled with little smooth muscle).

For the second part of the question, a breadth of knowledge was required. Candidates were expected to address the following physiological features of the pulmonary circulation: volume, pressure, resistance, regulation and regional distribution and function. Marks were apportioned to each section, so it was important to write something on each section. Focussing on one
section in detail (e.g., a very detailed description of West’s Zones) usually came at the expense of missing one or more of the other sections, most commonly the functions of the pulmonary circulation. Indeed, candidates that scored well provided information on each section and for the functions of the pulmonary circulation mentioned more than gas exchange.