Anatomy of Brain Blood Supply

Blood Supply to the Brain

• The two main vessels that supply blood to the brain are the Internal Carotid Artery and Vertebral Artery.
• The Internal Carotid Artery has four segments.

Internal Carotid Artery

• The petrosal segment of the Internal Carotid Artery lies in the carotid canal.
• The petrosal segment gives rise to the Caroticotympanic arteries at the end of the carotid canal.
• The branches of the cerebral segment of the Internal Carotid Artery are:
  • Ophthalmic artery
  • Anterior cerebral artery
  • Middle cerebral artery
  • Posterior communicating artery
  • Anterior choroid artery (sometimes)

Vertebral Artery

• The pathway of the Vertebral Artery is through the foramina of the transverse processes (C1-C6), piercing the atlanto-occipital membrane and going through the foramen magnum.
• Both Vertebral Arteries join on the inferior margin of the pons and form the Basilar Artery.
• The branches of the Vertebral Artery are:
  • Cervical (Muscular, Spinal) and Cranial (posterior inferior cerebellar artery, posterior spinal artery, anterior spinal artery)

Basilar Artery

• The Basilar Artery runs in the basilar sulcus on the ventral surface of the pons.
• The branches of the Basilar Artery are:
  • Anterior inferior cerebellar artery
  • Labyrinthine artery
  • Superior cerebellar artery
  • Posterior cerebral artery
  • Pontine artery

Cerebral Arterial Circle (Circle of Willis)

• The Cerebral Arterial Circle surrounds the hypothalamus.
• The arteries that form the Cerebral Arterial Circle are:
  • 1. Anterior communicating artery (from Internal Carotid Artery)
  • 2. Anterior cerebral artery (ICA)
  • 3. Internal Carotid Artery
  • 4. Posterior communicating artery (ICA)
  • 5. Posterior cerebral artery
  • 6. Basilar Artery

Anterior Cerebral Artery

• The first segment of the Anterior Cerebral Artery is located between the Internal Carotid and Anterior Communicating Arteries.
• The first segment of the Anterior Cerebral Artery supplies:
  • Thalamo-striatal arteries
  • Short middle artery and Long middle artery (HAUBNER’S artery)
  • Putamen
  • Head of the caudate nucleus
  • Anterior crus of the internal capsule
• The branches of the second segment of the Anterior Cerebral Artery are:
  • Medial fronto-basilar artery
  • Polar frontal artery
  • Anterior medial frontal artery
  • Intermediate medial frontal artery
  • Posterior medial frontal artery
  • Paracentral artery
  • Cingular branch
  • Precuneal artery

Middle Cerebral Artery

• The three parts of the Middle Cerebral Artery are:
  • Sphenoid part
  • Insular part
  • Cortical part (terminal)
• The Insular part of the Middle Cerebral Artery goes between the parieto-frontal and temporal operculum.
• The branches of the Middle Cerebral Artery are:
  • Middle branches (striato-capsular)
  • Frontal branches
  • Temporal branches
  • Parietal branches
  • Terminal branches
• The Middle Cerebral Artery supplies:
  • Thalamus
  • Corpus striatum
  • Insula
  • Cortex (lateral surface and medial of the anterior part of the temporal lobe)

Posterior Cerebral Artery

• The first segment of the Posterior Cerebral Artery is located between the Basilar Artery and Posterior Communicating Artery.
• The second segment of the Posterior Cerebral Artery passes around the midbrain in the cistern and through the tentorial notch, reaching the medial surface of the temporal lobe.
• The branches of the Posterior Cerebral Artery are:
  • Posterior Choroid artery
  • Thalamo-perforated arteries
  • Geniculo-thalamic artery
  • Temporal
  • Occipital
  • Occasionally parietal

Cerebral Veins

• The types of cerebral veins are:
  • Superficial veins
  • Deep veins
• Superficial veins collect blood from the cortex of the pallium and its neighbors.
• Superficial veins empty to the sinuses of the dura mater.
• The superior cerebral veins drain the blood of the supero-lateral and medial surface.
• The inferior cerebral veins drain the blood of the inferior and inferior part of the supero-lateral surface.
• The function of the middle superficial cerebral vein is to drain blood of the supero-lateral surface and empty to the cavernous sinus or spheno-parietal sinus.
• The Great Cerebral Vein empties to the proximal part of the straight sinus.
• The tributaries of the Internal Cerebral Vein are:
  • Thalamo-striate vein
  • Choroid vein
  • Vein of the vellum pallucidum
• The anterior cerebral vein drains the orbital surface of the frontal lobe.
• The middle deep vein drains the insula and operculum.
• The tributaries of the Great Cerebral Vein are:
  • Internal Cerebral Vein
  • Basilar Vein

Cerebrospinal Fluid

• Cerebrospinal fluid is secreted by the Choroid Plexus.
• The circulation pathway of cerebrospinal fluid is:
  • Lateral ventricle
  • Interventricular foramen
  • Third ventricle
  • Aqueduct
  • Fourth ventricle
  • Medial and lateral foramina
  • Subarachnoid space
  • Absorption in sinuses of the dura matter and veins of the vertebral canal.