The brain is supplied with blood by a single anterior spinal artery and two posterior spinal arteries.
The anterior spinal artery is Y shaped coming from 2 vertebral arteries at the medulla, descending on the ventral midline. The posterior spinal arteries come from the vertebral arteries, running caudally on the posterolateral surface of the spinal cord.
Radicular arteries from segmental vessels ascend the cervical, intercostal and lumbar arteries. The great radicular artery comes from a lateral intercostal or lumbar artery between T8-L3.
The venous drainage of the spinal cord has a similar pattern to the arterial supply. All the vessels drain via the anterior and posterior radicular veins into the internal vertebral venous plexus. This is situated between the dura mater and vertebral periosteum.
The brain receives blood through the internal carotid arteries and vertebral arteries. The internal carotid comes from the common carotid artery, entering the middle fossa of the cranial cavity through the carotid syphon then moving through the cavernous sinus and upwards on the medial aspect of anterior clinoid process and then being lateral to the optic chiasma.
The internal carotid artery branches to hypophyseal, opthalamic and anterior choroidal arteries and the posterior communicating artery which forms part of the circle of willis.
The internal caarotid artery divides into 2 terminal branches-anterior and middle cerebral arteries.
The anterior goes medially above the optic nerve, passing into the great longitudinal fissure between the frontal lobes. It is joined by the anterior communicating artery. It follows the longitutdinal…