In the LTI initialization, the brain depends on the blood supply of two internal carotid arteries (carotid or anterior system) and two vertebral ar...

In the LTI initialization, the brain depends on the blood supply of two internal carotid arteries (carotid or anterior system) and two vertebral arteries (vertebrobasilar or posterior system). The carotid system is related to anterior circulation stroke, while the vertebrobasilar system is related to posterior circulation stroke. At the base of the skull, these arteries form the polygon or circle of Willis, from which the main arteries for cerebral vascularization originate. The right and left internal carotid arteries (ICA) originate from the common carotid artery, bifurcating at the level of the thyroid cartilage. They enter the skull through the carotid canal and originate the middle and anterior cerebral arteries. The vertebral arteries originate from the proximal portion of the subclavian arteries, ascend in the neck passing through the transverse foramina of the cervical vertebrae, and enter the skull through the foramen magnum. The vertebral arteries bifurcate originating the basilar artery, which irrigates the posterior part of the inferior face of each cerebral hemisphere. PHYSIOPATHOLOGY IN NEUROLOGICAL DYSFUNCTIONS 102 Anterior communicating artery Anterior cerebral artery Ophthalmic artery Middle cerebral artery Common carotid artery Anterior choroidal artery Posterior communicating artery Posterior cerebral artery Superior cerebellar artery Basilar artery Pontine arteries Anterior inferior cerebellar artery Vertebral artery Anterior spinal artery 0 diagram of the circle of Willis inferior posterior Right common carotid artery Left common carotid artery Right subclavian artery Left subclavian artery Arch Unnamed artery Ascending aorta Left coronary artery Right coronary artery Descending thoracic aorta Supravalvular ridge Diaphragm Abdominal aorta Common artery Ascending aorta Figure 3 The anatomy of the arteries that irrigate Source: Shutterstock Accessed on: 03/26/2021 Cerebellum and basal nuclei

The brain depends on the blood supply of two internal carotid arteries and two vertebral arteries.
The carotid system is related to posterior circulation stroke.
The vertebrobasilar system is related to anterior circulation stroke.
The arteries that form the circle of Willis originate the main arteries for cerebral vascularization.
The vertebral arteries originate from the proximal portion of the subclavian arteries.