Arteries of the brain II (Latin)

The main artery of the anterior circulation of the brain is the a. carotis interna which terminates as the a. anterior cerebri and a. media cerebri.The main artery of the posterior circulation is the a. vertebralis. It enters the cranium via the foramen magnum and gives off several rami which include rr. meningeales, aa. spinales anteriores et posteriores as well as the a. cerebellaris posterior inferior. After this, the two aa. vertebrales converge to form the a. basilaris. This vessel courses vertically across the pons and fossa cranialis posterior where it gives off several branches namely the a. cerebelli inferior anterior, aa. labyrinthi, aa. pontis, aa. mesencephalicae, a. superior cerebelli. The a. basilaris terminates as a bifurcation which gives off the paired aa. posteriores cerebri that contribute to the circulus arteriosus cerebri (circ. Willisi). The circle of Willis is an anastomotic loop/ring formed between four paired arteries and one unpaired artery which facilitates collateral blood between the anterior and posterior cerebral circulations as well as the right and left blood supply. Several small perforating (central) arteries (rr. centrales) emerge from the circle of Willis, many of which pass into the brain directly and supply the cortex and subcortical structures.