Final answer:
The Circle of Willis does not include the right and left vertebral arteries; instead, it is composed of the right and left internal carotid arteries, right and left anterior cerebral arteries, and the anterior communicating artery.
Step-by-step explanation:
The Circle of Willis is an essential part of the cerebral circulation system in our brain. Considering the components that form this circle, it is the right and left vertebral arteries that are not part of the Circle of Willis. Rather, they merge to form the basilar artery, which in turn contributes to the posterior part of the Circle of Willis by connecting with the posterior cerebral arteries.
The correct components of the Circle of Willis include the right and left internal carotid arteries, which enter the cranium through the carotid canal, the right and left anterior cerebral arteries, and the anterior communicating artery. All these components play a significant role in ensuring efficient blood flow to the brain, and they provide a safety net for cerebral circulation in case one part of the system is compromised.