Circulus arteriosus is formed by
Circulus arteriosus or "circle of Willis" is a anatomical peculiarity of cerebral arteries.
It is formed by
• Anteriorly by anterior communicating artery.
• Posteriorly by basilar artery.
• On each side by anterior cerebral, posterior cerebral, posterior communicating and internal carotid arteries.
Anterior communicating artery.
Basilar artery.
Anterior, posterior cerebral and posterior communicating artery.
All of the above.