Branches of the PCA

Peduncular, ambient, and quadrigeminal segments are named after the cisterns through which they pass. The P1 segment (before the PCoA branches) is also called the mesencephalic artery, or the precommunal portion of the PCA. In 10 %, the PCA originates from the carotid in a persistent fetal pattern. The branches are the paramedian mesencephalic arteries, the thalamic-subthalamic arteries, and the medial posterior choroidals, NOT the polar arteries that come off the PCoA. The ambient portion of the PCA gives off the peduncular perforatings and the thalamogeniculates supplying the lateral thalamus. Then the lateral posterior choroidals, then the four cortical branches: anterior temporal (from the ambient segment), posterior temporal (between the tentorium and medial temporal lobe), parieto-occipital (which give off the posterior pericallosal arteries which circle the splenium of the corpus callosum) and calcarine arteries.