Blood Supply of Brain
The brain is supplied by blood from two main systems, the anterior and posterior circulation. The anterior circulation is provided by the internal carotid artery and its branches, while the posterior circulation is supplied by the vertebral arteries and their branches.
Brain and Circle of Willis
The circle of Willis is a vascular ring formed by the anastomosis of several arteries in the brain. It plays a crucial role in regulating blood flow to the brain.
Formation and Branches of Circle of Willis
The circle of Willis is formed by the following arteries:
- A. Communicating Artery: Connects the two internal carotid arteries.
- A. Anterior Cerebral Artery: Branches off the internal carotid artery.
- A. Posterior Cerebral Artery: Branches off the internal carotid artery.
- A. Basilar Artery: Formed by the fusion of the two vertebral arteries.
- A. Posterior Communicating Artery: Connects the internal carotid artery to the posterior cerebral artery.
- A. Anterior Communicating Artery: Connects the two anterior cerebral arteries.
Distribution of Circle of Willis
The circle of Willis distributes blood to the brain through the following paths:
- Anterior cerebral artery → Anterior communicating artery → Internal carotid artery
- Posterior cerebral artery → Posterior communicating artery → Internal carotid artery
- Basilar artery → Posterior cerebral artery
Applied Anatomy
In applied anatomy, the circle of Willis is important in understanding the blood supply to the brain. It is used in neurosurgery to diagnose and treat conditions such as aneurysms and arteriovenous malformations.
Key Points
- The circle of Willis is a vascular ring formed by the anastomosis of several arteries in the brain.
- It regulates blood flow to the brain and is essential for maintaining cerebral blood circulation.
- The circle of Willis is formed by the communicating arteries, anterior cerebral arteries, posterior cerebral arteries, basilar artery, and posterior communicating arteries.
- The circle of Willis distributes blood to the brain through the anterior and posterior cerebral arteries.
- In applied anatomy, the circle of Willis is used in neurosurgery to diagnose and treat conditions such as aneurysms and arteriovenous malformations.