The vascular anatomy of the cavernous body of green monkeys.

The cavernous body of monkeys was studied by light and electron microscopy. The intima of the deep artery contained longitudinal muscle cells, but cushions or valve-like structures were not found. Some branches of the deep artery directly connected to subtunical veins. Only the helicine arteries which drained into the cavernous sinuses displayed subendothelial cushions. The "epitheloid cells" forming the cushions unequivocally were smooth muscle cells. It is suggested that the helicine arteries open during tumescence, thereby diverting blood from the shunt vessels into the dilating sinuses, and that the rising intracavernosal pressure eventually occludes the shunt vessels. The endothelium of the sinuses contained many intermediate filaments, but there was no morphological evidence for the hypothesis that the cells are contractile.