posterior communicating artery (PCOM)
The brain and
arteries at base of the brain. Circle of Willis is formed near center. The temporal pole of the cerebrum and a portion of the cerebellar hemisphere have been removed on the right side. Inferior aspect (viewed from below).
The posterior communicating artery (PCOM or P Comm) makes up the posterior linkage in the circle of Willis.
Gross anatomy
Course
The PCOM originates from the posterior aspect of the C7 (communicating) segment of the internal carotid artery and extends posteriormedially to anastomose with the ipsilateral posterior cerebral artery and form part of the circle of Willis.
Branches
The PCOM gives off many fine, scarcely visible, perforating branches. The largest perforating branch is called the premamillary (or anterior thalamoperforating) artery.
Vascular territory
Perforators from the PCOM supply:
- posterior part of the optic chiasm and optic tract
- posterior part of the hypothalamus and mammillary bodies
- part of the thalamus
Variant anatomy
- fetal origin of posterior cerebral artery: common (see case 1)
- PCOM duplication: rare
- PCOM fenestration: extremely rare
- PCOM hypoplasia: incidence ~35%
- PCOM infundibulum (see case 2)
- anterior choroidal artery origin from PCOM
Siehe auch:
und weiter:
Assoziationen und Differentialdiagnosen zu posterior communicating artery (PCOM):