Question

Four major brain vessels anastomose at the base of the brain.

A) Anterior cerebral artery
B) Posterior cerebral artery
C) Middle cerebral artery
D) Circle of Willis

Answer 1

Four major brain vessels anastomose at the base of the brain: the anterior cerebral artery, the posterior cerebral artery, the middle cerebral artery, and the circle of Willis. The anterior cerebral artery and the anterior communicating artery form the anterior portion of the arterial circle. The posterior portion of the arterial circle is formed by the posterior cerebral artery and the posterior communicating artery.

Step-by-step explanation:

Four major brain vessels anastomose at the base of the brain: the anterior cerebral artery, the posterior cerebral artery, the middle cerebral artery, and the circle of Willis. The anterior cerebral artery and the anterior communicating artery form the anterior portion of the arterial circle. The posterior portion of the arterial circle is formed by the posterior cerebral artery and the posterior communicating artery, which arise from the basilar artery. The basilar artery is an anastomosis that begins at the junction of the two vertebral arteries and sends branches to the cerebellum and brain stem.