Microvascular architecture of the pampiniform plexus-testicular artery system in the rat: a scanning electron microscope study of corrosion casts.

The vascular architecture of the rat pampiniform plexus was studied by scanning electron microscopy of vascular corrosion casts. The plexus consists of a thick bundle of many anastomosing veins that entirely and closely surround the convoluted segments of the testicular artery. This specially developed close contact of the pampiniform plexus with the testicular artery may allow heat exchange between the plexus and the artery to maintain the cooled condition of the testis. The epididymal arteries are also closely surrounded by the networks of the epididymal veins. It is likely that heat exchange may operate even between these epididymal vessels. The ductus deferens is provided with no vascular channels for such heat exchange. A loose or coarse capillary network is always observed between the testicular artery and the pampiniform plexus. This network is supplied by the epididymal arteries and drains into the pampiniform plexus.