Testicular microvascularization in common tree shrew (Tupaia glis)

Abstract

Fifteen common tree shrews weighing between 120-180 g are used. Their testes are prepared for studying with LM, with TEM and with corrosion cast technique / SEM. It is found that the tree shrew testicular blood supply is from testicular artery branching from the abdominal aorta. In the spermatic cord it become convuluted and surrounded by pampiniform plexus. When the artery emerges from the pampiniform plexus at rostro-medial pole of the testis, it courses caudally along the medial border and then rostrally along the lateral border of the gonad. While curving along the lateral border, it gives off 4-5 branches penetrating into the testicular parenchyma and further divide into small arterioles before giving rise to capillary plexus surrounding each seminiferous tubule. These capillaries join each other to form small and then larger venules which course along the ventral and dorsal surfaces of the testis. The venules on the ventral and dorsal surfaces drain the blood into the collecting veins on the lateral and medial borders of the gland, respectively. These collecting veins become the pampiniform plexus. In addition, capillaries from the medullary region of the testis empty the blood into the medullary vein which course rostrally and finally join the pampiniform plexus. With TEM study, it is found that the capillaries in the testis are continuous type.