Unlock hundreds more features
Save your Quiz to the Dashboard
View and Export Results
Use AI to Create Quizzes and Analyse Results

OR
Sign inSign in with Facebook
Sign inSign in with Google
Quizzes > Health & Medicine > Human Anatomy & Medicine

Master the Circle of Willis: Take the Quiz!

Ready for the Circle of Willis labeling quiz? Dive in now!

Difficulty: Moderate
2-5mins
Learning OutcomesCheat Sheet
Paper art illustration for Circle of Willis labeling quiz on dark blue background

This Circle of Willis labeling quiz helps you label each artery in the circle and check gaps before an exam in neuroanatomy. After you play, review the cranial nerves guide or keep going with the blood vessels quiz right now.

Which artery connects the two anterior cerebral arteries in the Circle of Willis?
Middle cerebral artery
Internal carotid artery
Posterior communicating artery
Anterior communicating artery
The anterior communicating artery (AComm) bridges the left and right anterior cerebral arteries, completing the anterior portion of the Circle of Willis. This small vessel is a frequent site of aneurysm formation. It plays a critical role in collateral circulation if one ACA becomes occluded.
Which two arteries form the posterior portion of the Circle of Willis?
Anterior cerebral arteries
Posterior cerebral arteries
Middle cerebral arteries
Vertebral arteries
The posterior cerebral arteries (PCAs) complete the posterior half of the Circle of Willis by connecting to the basilar artery bifurcation. They supply the occipital lobes and inferomedial temporal lobes. PCAs are connected to the internal carotid distribution via the posterior communicating arteries.
Which artery is NOT part of the Circle of Willis?
Posterior communicating artery
External carotid artery
Internal carotid artery
Anterior cerebral artery
The external carotid artery supplies the face and neck, and is not part of the intracranial Circle of Willis. The internal carotid, anterior cerebral, and posterior communicating arteries all form components of the circle. The Circle of Willis encircles the pituitary fossa at the base of the brain.
The Circle of Willis primarily functions to:
Regulate blood pressure
Filter waste products
Oxygenate blood
Provide collateral circulation
The Circle of Willis is an arterial polygon that allows for collateral blood flow between the anterior and posterior circulations if one part becomes occluded. It does not itself regulate pressure or oxygenate blood. Its main role is to maintain perfusion to the brain in case of vessel compromise.
Which artery is the direct continuation of the basilar artery within the Circle of Willis?
Middle cerebral artery
Posterior cerebral artery
Anterior cerebral artery
Anterior communicating artery
At the top of the basilar artery, it bifurcates into the paired posterior cerebral arteries (PCAs), making them the direct continuation. These arteries supply the occipital lobes and the inferior temporal lobes. They connect anteriorly via the posterior communicating arteries.
The A1 segment of the anterior cerebral artery refers to:
The segment distal to the anterior communicating
The segment between the internal carotid and anterior communicating artery
The segment within the callosal sulcus
The segment between A2 and A3
The A1 segment of the ACA extends from the internal carotid bifurcation to the anterior communicating artery. The A2 segment begins distal to the AComm. This anatomical division is important in angiography and surgical planning.
A fetal origin of the posterior cerebral artery is characterized by which of the following?
Direct origin from the vertebral artery
A large posterior communicating artery relative to the P1 segment
An absent posterior communicating artery
An enlarged P1 segment relative to PComms
In a fetal PCA origin, the posterior communicating artery is larger than the P1 segment of the PCA, indicating continued dependence on the internal carotid. This variation occurs in approximately 10 - 30% of individuals. It has clinical importance in collateral flow patterns.
Which variation is most commonly seen in the Circle of Willis?
Bilateral fetal posterior cerebral arteries
Absence of internal carotid artery
Hypoplasia of posterior communicating artery
Duplication of anterior communicating artery
The most frequent anatomical variant is hypoplasia or aplasia of one or both posterior communicating arteries. This reduces the redundancy offered by the circle. Duplication of AComm and bilateral fetal PCAs are less common.
Which segment is defined as the post-communicating portion of the anterior cerebral artery?
A4 segment
A3 segment
A1 segment
A2 segment
The A2 segment lies distal to the anterior communicating artery and is also called the post-communicating segment. The A1 segment is pre-communicating. A3 and A4 segments refer to more distal branches in the interhemispheric fissure.
Aneurysms are most frequently found at which location in the Circle of Willis?
Anterior communicating artery junction
Middle cerebral artery bifurcation
Posterior communicating artery junction
Basilar tip
The anterior communicating artery junction is the most common site for intracranial aneurysms, accounting for ~35 - 40% of cases. Hemodynamic stress at this small vessel junction predisposes to aneurysm formation. Posterior communicating and MCA bifurcation aneurysms are also common but less frequent.
In carotid artery occlusion, the primary collateral flow to the middle cerebral artery comes from which arterial connection?
Posterior cerebral artery
Anterior communicating artery
Posterior communicating artery
External carotid anastomoses
When the ipsilateral internal carotid artery is occluded, blood from the contralateral ICA can cross via the anterior communicating artery to supply the middle cerebral artery territory. Posterior communicating pathways may contribute but are usually secondary. External carotid contributions are minor.
Which developmental anomaly results in the absence of the anterior communicating artery?
Moyamoya disease
Holoprosencephaly
Dural arteriovenous fistula
Midline division anomaly
A midline division anomaly during embryogenesis can lead to absence or hypoplasia of the anterior communicating artery. Holoprosencephaly is forebrain fusion rather than specific vascular absence. Dural AV fistulas and Moyamoya disease are acquired or progressive vascular conditions.
In cases of basilar artery stenosis, which collateral pathway via the Circle of Willis is most significant?
External carotid to ophthalmic artery
Middle cerebral to posterior cerebral arteries
Posterior communicating to internal carotid artery
Anterior communicating to vertebral arteries
When basilar flow is compromised, blood from the anterior circulation can reach the posterior cerebral arteries via enlarged posterior communicating arteries. This collateral route helps maintain perfusion to the brainstem and occipital lobes. Anterior communicating arteries do not connect to vertebral systems.
Flow reversal in the anterior communicating artery typically indicates pathology of which vessel?
One anterior cerebral artery A1 segment stenosis/occlusion
Middle cerebral artery occlusion
Basilar artery thrombosis
Posterior cerebral artery P1 stenosis
Flow in the anterior communicating artery may reverse when one A1 segment of the anterior cerebral artery is stenosed or occluded, allowing cross-flow from the patent side. This compensates for deficient perfusion. PCA or MCA lesions do not directly cause AComm reversal.
0
{"name":"Which artery connects the two anterior cerebral arteries in the Circle of Willis?", "url":"https://www.quiz-maker.com/QPREVIEW","txt":"Which artery connects the two anterior cerebral arteries in the Circle of Willis?, Which two arteries form the posterior portion of the Circle of Willis?, Which artery is NOT part of the Circle of Willis?","img":"https://www.quiz-maker.com/3012/images/ogquiz.png"}

Study Outcomes

  1. Identify Major Arteries -

    Understand the names and locations of the anterior, middle, and posterior cerebral arteries, as well as the communicating arteries that form the Circle of Willis.

  2. Analyze Arterial Connections -

    Explain how each vessel interconnects to maintain cerebral blood flow and collateral circulation within the arterial circle.

  3. Label Accurately -

    Demonstrate precise labeling skills using the Circle of Willis labeling quiz interface, reinforcing your retention of key anatomical details.

  4. Differentiate Anatomical Variations -

    Distinguish common anatomical variants of the Circle of Willis and recognize their potential impact on cerebral perfusion.

  5. Evaluate Quiz Performance -

    Track and interpret your quiz results to pinpoint knowledge gaps and guide targeted review of Circle of Willis anatomy.

Cheat Sheet

  1. Main arterial components -

    Memorize the six principal vessels that form the circle of Willis: two Anterior Cerebral Arteries (ACAs), one Anterior Communicating Artery (AComA), two Posterior Cerebral Arteries (PCAs), two Posterior Communicating Arteries (PComAs), and the Internal Carotid Arteries (ICAs). Boost your recall with the "A-1, ACom, P-1" mnemonic from Gray's Anatomy - an edge in any circle of willis quiz!

  2. Role in collateral circulation -

    The circle of Willis provides a critical backup route for cerebral blood flow if a major artery is occluded, thanks to communicating arteries linking anterior and posterior circulation. Johns Hopkins neurology highlights bookmark this anastomotic network for mitigating ischemia - expect questions about it in every circle of willis anatomy quiz!

  3. Common anatomical variations -

    Over 50% of individuals exhibit asymmetry or hypoplasia in one of the communicating arteries, most often the AComA or PComA, impacting the classic circle of willis label configuration. Forged from American Association of Neurological Surgeons data, recognizing these variants impresses in diagnosis and neurosurgical planning!

  4. Clinical significance and aneurysm hotspots -

    Berry aneurysms frequently arise at the ACA - AComA junction and the PComA - ICA junction, making these two sites critical targets in the circle of willis labeling quiz. The Mayo Clinic emphasizes early detection in these regions to prevent subarachnoid hemorrhage - make spotting these hotspots a breeze in any circle of willis labeling quiz!

  5. Systematic labeling strategy -

    Start by identifying the midline structures on axial or 3D imaging, then trace outward to label the ACAs, PCAs, AComA, and PComAs sequentially - this method accelerates your accuracy in any circle of willis quiz. Radiopaedia.org recommends annotating one vessel at a time, using directional prefixes (e.g., A1 vs. A2 segments) to sharpen your precision when mapping the circle of willis label!

Make a Quiz (FREE) Copy & Edit This Quiz Create a Quiz with AI

Human Anatomy & Medicine Quizzes

Powered by: Quiz Maker