Arterial territories

The brain is supplied by the internal carotid arteries and vertebral arteries. They form, together with their branches, the circle of Willis.

The collateral cerebral circulation refers to the network of vascular channels that stabilize cerebral blood flow if main vessel is stenosed or occluded. Arterial insufficiency may be caused by thromboembolism, hemodynamic compromise, or a combination of these factors.

The arterial blood supply of the spinal cord is secured via three longitudinal arteries - a single anterior spinal artery (ASA) and the two posterior spinal arteries (PSA).

Variants in the arrangement of cerebral vessels are quite common. They often have low clinical significance, but their knowledge and recognition are fundamental if surgical or endovascular treatment is considered.

The cerebral veins drain the brain parenchyma into the dural venous sinuses and from there into the internal jugular veins. They are characterized by thin walls lacking muscular tissue and valves.