The posterior cerebral artery (PCA) is one of a pair of cerebral arteries that supply oxygenated blood to the occipital lobe, part of the back of the human brain. The two arteries originate from the distal end of the basilar artery, where it bifurcates into the left and right posterior cerebral arteries. These anastomose with the middle cerebral arteries and internal carotid arteries via the posterior communicating arteries.

Structure

The posterior cerebral artery is subdivided into 4 segments: P1: pre-communicating segment P2: post-communicating segment P3: quadrigeminal segment P4: cortical segment The branches of the posterior cerebral artery are divided into two sets, ganglionic and cortical.

Central branches

The following are central branches of the PCA, also known as perforating branches:

Posterior (choroidal) branches

The posterior choroidal branches of the posterior cerebral artery are sometimes referred to as a single posterior choroidal artery.

Cortical branches

The cortical branches are:

Development

The prenatal development of the posterior cerebral arteries in the fetus comes relatively late and arises from the fusion of several embryonic vessels near the caudal ends of the posterior communicating arteries supplying the mesencephalon and diencephalon. The PCA begins as such, as a continuation of the PCommA in the fetus with only 10–30% of fetuses having a prominent basilar origin. The fetal carotid origin of the PCA usually regresses as the vertebral and basilar arteries develop with the PCommA reducing is size. In most adults, the PCA sources from the anterior portion of the basilar artery. Only about 19% of adults retain PCommA dominance of the PCA with 72% having dominant basilar origin, and the rest having either equal prominence between PCommA and basilar artery, or a single exclusive source.

Clinical significance

Stroke

Signs and symptoms: Structures involved

Peripheral territory (cortical branches)

Central territory (ganglionic branches)

Additional images