Neuroanatomy Quiz: Cerebral Blood Supply

Blood Supply of the Brain

• The brain's arterial supply originates from two internal carotid arteries (ICAs) and two vertebral arteries.
• The ICAs ascend through the carotid canal, passing through the cavernous sinus.
• Branches of the ICA include the anterior choroidal artery, posterior communicating artery, ophthalmic artery, anterior cerebral artery (ACA), and middle cerebral artery (MCA).
• The vertebral arteries ascend through the transverse foramina of cervical vertebrae and unite to form the basilar artery.
• The basilar artery connects to the posterior communicating arteries to form the Circle of Willis.
• The Circle of Willis is a circulatory anastomosis that supplies blood to the brain.
• The posterior cerebral artery (PCA) branches from the basilar artery.

Arterial Supply - Brain

• The vertebral arteries supply the posterior part of the brain, including the brainstem and cerebellum.
• The internal carotid artery supplies the majority of the cerebrum.
• The anterior cerebral artery primarily supplies the medial surface of the frontal and parietal lobes.
• The middle cerebral artery supplies most of the lateral surface of the frontal, parietal, and temporal lobes.
• The posterior cerebral artery supplies the occipital lobe and parts of the temporal lobes.

Circle of Willis (CoW)

• The Circle of Willis is a circulatory anastomosis that connects the anterior and posterior cerebral circulation.
• It allows alternative pathways for blood flow in case of blockage or reduced blood flow to one part of the brain.
• The Circle of Willis connects the internal carotid arteries with the vertebral arteries.

Blood Supply of Cerebral Cortex

• The cerebral cortex receives blood from the anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA).
• The ACA primarily supplies the medial aspects of the frontal and parietal lobes.
• The MCA supplies the lateral aspects of the frontal, parietal, and temporal lobes.
• The PCA supplies the occipital lobe and parts of the temporal lobes.

Lobes of the Cerebral Cortex

• The brain is divided into four lobes: frontal, parietal, temporal, and occipital.
• The frontal lobe is located at the front of the brain.
• The parietal lobe is located behind the frontal lobe.
• The temporal lobe is located below the parietal lobe.
• The occipital lobe is located at the back of the brain.
• Specific regions within these lobes are functionally distinct.

Branches of Vertebral and Basilar Arteries

• The vertebral arteries give rise to anterior spinal artery, posterior spinal artery, and posterior inferior cerebellar artery (PICA).
• The basilar artery branches into the posterior cerebral artery (PCA), superior cerebellar artery (SCA), and anterior inferior cerebellar artery (AICA).

Blood Supply of Brainstem and Cerebellum

• The brainstem receives blood from branches of the vertebral and basilar arteries that form the posterior circulation.
• The cerebellum is supplied by the posterior inferior cerebellar artery (PICA), superior cerebellar artery (SCA), and anterior inferior cerebellar artery (AICA)

Cerebral Veins and Dural Sinuses

• Cerebral veins collect blood from the brain tissue.
• These veins empty into dural venous sinuses.
• Dural venous sinuses are large veins that drain venous blood from the brain and collect it into the internal jugular vein.

When Things Go Wrong

• Causes of subarachnoid hemorrhage (SAH) include aneurysms, arteriovenous (AV) malformations, bleeding diathesis, anticoagulants, tumors, vasculitis, and other causes.
• Various locations of saccular aneurysms are related to different branches of major brain arteries.

Cerebral Aneurysm

• Angiography is used to visualize and identify cerebral aneurysms.
• Compression on brain structures from aneurysm sites can cause neurological problems.