Internal carotid artery anatomy — Flashcards

Flashcard 1: In the Circle of Willis, which vessel connects the two anterior cerebral arteries?

Answer: Anterior communicating artery (ACom)

Extra: The anterior communicating artery is the most common site for berry (saccular) aneurysms. Rupture leads to subarachnoid hemorrhage, while large aneurysms can compress the optic chiasm, leading to bitemporal hemianopsia.

Flashcard 2: What is the largest terminal branch of the internal carotid artery?

Answer: Middle cerebral artery (MCA)

Extra: The MCA is the largest terminal branch of the internal carotid artery. It travels through the lateral (Sylvian) fissure and supplies the majority of the lateral surface of the cerebral hemisphere, including the motor and sensory areas for the face and upper limbs, and the primary language areas (Broca's and Wernicke's) in the dominant hemisphere.

Flashcard 3: Saccular aneurysms of the _____ communicating artery may cause compression of the CN III

Answer: posterior

Flashcard 4: Which cerebral artery supplies the anterior limb of the internal capsule? _____

Answer: Anterior cerebral artery

Flashcard 5: Saccular aneurysms of the _____ communicating artery may cause compression of the optic chiasm

Answer: anterior

Flashcard 6: What structure is most commonly compressed by an aneurysm of the anterior communicating artery?

Answer: Optic chiasm compression, resulting in bitemporal hemianopia.

Extra: Aneurysms of the anterior communicating artery (ACom) are the most common site of Berry aneurysms in the Circle of Willis. Due to their location, they can compress the optic chiasm, leading to visual field defects.

Flashcard 7: An aneurysm of which artery is most commonly associated with a CN III palsy?

Answer: CN III (Oculomotor nerve) palsy

Extra: Aneurysms of the posterior communicating artery (PCoA) typically cause a CN III palsy with pupil involvement (mydriasis), because the parasympathetic fibers are superficial on the nerve. Findings: Ptosis, "down and out" eye position, and a dilated pupil.

Flashcard 8: Where do saccular "berry" aneurysms tend to occur?

Answer: bifurcations in Circle of Willis; especially anterior and posterior communicating arteries

Flashcard 9: Identify the branch of the vertebral artery labeled as number 3 in the provided image.

Answer: posterior spinal arteries

Flashcard 10: Identify the artery in the vertebrobasilar system labeled as number 9 (the vessel formed by the union of branches from both vertebral arteries descending the spinal cord):

Answer: Anterior spinal artery

Extra: The anterior spinal artery is formed by the union of two small branches from the vertebral arteries. It descends in the anterior median fissure and supplies the anterior two-thirds of the spinal cord.