Front View Animation
Lateral View Animation
Midsagittal View Animation
- The head and brain receives its arterial blood supply via the carotid arteries which originate from the arch of the aorta. At the base of the ear the carotid artery branches into internal and external branches. The external carotid supplies the face, scalp, skull and meninges. An important branch is the middle meningeal artery. Laceration of this artery in the temporal area may cause an epidural hematoma.
- The internal carotid artery supplies the brain itself. It is commonly divided into its intracranial part which consists of the carotid siphon which traverses the base of the skull (cranium) and its extracranial part which branches into the middle cerebral, anterior cerebral and posterior cerebral arteries to form the Circle of Willis.
- The anterior cerebral artery supplies the frontal lobes and medial aspects of the parietal and occipital lobes.
- The middle cerebral artery, also called the artery of stroke, supplies the frontoparietal somatosensory cortex. Infarcts in its territory result in contralateral hemiparesis.
- The posterior cerebral artery supplies the occipital and inferior temporal lobes including the hippocampus.
- The Circle of Willis consists of the posterior communicating arteries and the anterior communicating arteries. Striate arteries also known as "penetrators" branch from the Circle of Willis to supply the basal ganglia and thalamus. These vessels are a common source of strokes. Both small ischemic infarcts, known pathologically as lacunes, and major intracerebral hemorrhages occur within the tissue supplied by these penetrating arteries.
- The Medulla is supplied by the vertebral arteries. The anterior spinal artery arises at the bifurcation of the vertebrals and descends to supply the spinal cord.
- The vertebral arteries fuse at the pontomedullary junction to form the basilar artery. The posterior inferior cerebellar artery arises from the caudal aspect of the basilar artery. Penetrators from the basilar artery supply the pons. The superior cerebellar artery arises superiorly from the basilar artery. The basilar artery then bifurcates into the posterior cerebral arteries.
- Large veins in the subrachnoid space empty in the dural venous sinuses. The sagittal sinus is located in the dura wiithin the longitudinal fissure. The transverse sinus is located in the dura of the caudal tentorium. The Vein of Galen is a medial and rostral extension of the transverse sinus in the tentorium.
last update Jan 21, 2002