DOH Anatomy & Physiology 2

Question 1

The Circle of Willis provides collateral circulation to the brain. Which artery connects the two anterior cerebral arteries?

Accepted Answer

Anterior communicating artery

Answer

The anterior communicating artery is a short vessel connecting the left and right anterior cerebral arteries, completing the anterior part of the Circle of Willis.

Question 2

Which enzyme converts angiotensin I to angiotensin II in the renin-angiotensin-aldosterone system?

Accepted Answer

Angiotensin-converting enzyme (ACE)

Answer

ACE (Angiotensin-Converting Enzyme), found predominantly in pulmonary endothelium, cleaves angiotensin I to produce the active vasoconstrictor angiotensin II.

Question 3

What is the primary function of surfactant produced by type II pneumocytes in the alveoli?

Accepted Answer

To reduce alveolar surface tension and prevent collapse

Answer

Pulmonary surfactant reduces alveolar surface tension, preventing alveolar collapse (atelectasis) at end-expiration, and is critical for normal lung compliance.

Question 4

The hepatic portal vein drains venous blood to the liver from which organs?

Accepted Answer

Gastrointestinal tract and spleen

Answer

The hepatic portal vein carries nutrient-rich and potentially toxic venous blood from the gastrointestinal tract (stomach to rectum) and spleen to the liver for processing.

Question 5

Which nerve innervates the diaphragm and originates from cervical spinal levels C3, C4, and C5?

Accepted Answer

Phrenic nerve

Answer

The phrenic nerve (C3, C4, C5 — 'keeps the diaphragm alive') provides motor and sensory innervation to the diaphragm, the primary muscle of respiration.

HAAD/DOH Abu Dhabi Practice Test

HAAD/DOH Abu Dhabi Practice Test

DOH Anatomy & Physiology 2