Blood supply to the brain

Summary

In this video, Dr. Morton explains the blood supply to the brain, focusing on the internal carotid and vertebral-basilar arteries. He describes how these arteries supply both the anterior and posterior regions of the brain, including critical branches such as the ophthalmic, anterior cerebral, and middle cerebral arteries. Dr. Morton also highlights the Circle of Willis, a vital collateral circulation system that ensures brain function even in the event of arterial blockages. The video provides an in-depth, visual exploration of brain anatomy, illustrating how blood flow supports brain health and resilience.

Takeaways

• 😀 The brain is supplied by two main arteries: the internal carotid and the vertebral-basilar artery, each serving different parts of the brain.
• 😀 The internal carotid artery supplies the anterior circulation of the brain, while the vertebral-basilar artery supplies the posterior circulation.
• 😀 The internal carotid artery passes through several regions: cervical, petrous, cavernous, and cerebral parts, each playing a different role in supplying blood to the brain.
• 😀 A critical branch of the internal carotid artery is the ophthalmic artery, which supplies the eye and retina, with clinical importance in cases of diabetes and clot-related blindness.
• 😀 The anterior cerebral artery supplies the medial aspect of the cerebral hemisphere, extending to the parietal lobe.
• 😀 The middle cerebral artery supplies the lateral aspects of the brain, excluding the superior frontal and parietal lobes, and the inferior temporal lobe.
• 😀 The vertebral arteries supply the posterior circulation, with branches like the posterior inferior cerebellar artery and anterior spinal artery, crucial for spinal cord and cerebellum function.
• 😀 The basilar artery, formed by the fusion of the vertebral arteries, gives rise to branches like the superior cerebellar artery, supplying the top of the cerebellum.
• 😀 The posterior cerebral artery, which is the terminal branch of the basilar artery, supplies the occipital lobe and portions of the temporal lobe.
• 😀 The Circle of Willis is a collateral circulation network between the internal carotid and vertebral-basilar arteries, providing redundancy if one part is blocked, ensuring blood supply continuity to the brain.

Q & A

What are the two main arteries that supply blood to the brain?

The two main arteries that supply blood to the brain are the internal carotid artery and the vertebral basilar artery.

What areas of the brain are supplied by the internal carotid artery?

The internal carotid artery supplies the anterior circulation of the brain, which includes everything above the dashed line running through the temporal and occipital lobes.

How do the vertebral arteries supply blood to the brain?

The vertebral arteries ascend through the neck, enter the skull through the foramen magnum, and join to form the basilar artery. This artery then supplies the posterior circulation of the brain.

What is the Circle of Willis and what is its function?

The Circle of Willis is a collateral circulation system that connects the two internal carotid arteries and the vertebral basilar artery, allowing for blood flow redundancy. If one part of the circle is occluded, blood can still reach other areas through alternate routes.

What is the significance of the ophthalmic artery?

The ophthalmic artery, a branch of the internal carotid artery, supplies blood to the eye. One important branch is the central artery of the retina, which can cause blindness if blocked.

What does the anterior cerebral artery supply?

The anterior cerebral artery supplies the medial aspect of the cerebral hemisphere, extending all the way back to the parietal lobe.

How does the middle cerebral artery differ in its distribution compared to the anterior cerebral artery?

The middle cerebral artery supplies the lateral aspect of the cerebral hemispheres, except for the superior portions of the frontal and parietal lobes and the inferior part of the temporal lobe.

What role does the posterior cerebral artery play in brain circulation?

The posterior cerebral artery supplies the occipital lobe, the primary visual cortex, and parts of the temporal lobe, including the posterior medial and inferior portions.

What are the branches of the basilar artery?

The basilar artery, formed by the union of the two vertebral arteries, gives rise to several branches, including the anterior inferior cerebellar artery, superior cerebellar artery, and posterior cerebral artery.

Why is the Circle of Willis important in the event of an artery occlusion?

The Circle of Willis provides redundancy in blood supply. If an artery within the circle becomes blocked, blood can be rerouted from the contralateral side to ensure continuous brain perfusion.