How do the posterior cerebral arteries arise?

The posterior cerebral arteries arise from the basilar artery, which forms at the junction of the two vertebral arteries. This anatomical feature is essential for understanding the blood supply to the brain, particularly to the occipital lobe and the inferior surface of the temporal lobe.

The basilar artery itself is formed by the union of the vertebral arteries, which ascend alongside the brainstem and provide a vital connection to the posterior circulation of the brain. Once the basilar artery reaches the level of the midbrain, it bifurcates into the two posterior cerebral arteries, which are crucial for delivering oxygenated blood to specific brain regions.

Understanding this origin helps in recognizing the vascular supply patterns and potential implications in clinical conditions such as strokes or other cerebrovascular pathology affecting the posterior part of the brain.