Which arteries are included in the circle of Willis and commonly associated with berry aneurysms?

• A. PCA, MCA, ACA, ICA
• B. PCA, ACA, Basilar, Vertebral
• C. Renal and carotid, Vertebral and Basilar
• D. Pulmonary, Coronary, Cerebral, Cerebellar

Answer: (A)

The circle of Willis is a ring of arteries at the base of the brain formed by connections between the internal carotid system and the vertebrobasilar system. Berry (saccular) aneurysms tend to develop at the branching points within this circle, especially where vessels divide or connect, such as near the anterior communicating artery and at the origins where the posterior communicating arteries join the internal carotid.

The arteries listed—posterior cerebral, middle cerebral, anterior cerebral, and internal carotid—are the major cerebral vessels involved in forming and feeding the circle of Willis, and these are the sites where berry aneurysms most commonly occur. The other options include arteries that aren’t part of this cerebral circle or are irrelevant to this context, such as renal, pulmonary, or coronary arteries.