Histology of normal and cryptorchid testicles
Keywords: histology, cryptorchid, stallion, testicle
Image size: 930 x 1398px
Disruption of spermatogenesis mediated by high body temperature; in this case due to cryptorchidism. Spermatogenesis is disrupted by an increase in body temperature of only two to three degrees. Due to cooling by the pampiniform plexus, the temperature of arterial blood in the spermatic artery drops from approximately 39°C to 34°C within the scrotum.1
Even brief increases in systemic body temperature can disrupt spermatogenesis significantly.
In the top image, spermatogenesis is proceeding normally. The area under the green ring shows that spermiation i.e. completion of spermatogenesis occurring. In the lower image the seminiferous tubules are empty (green arrows) except for spermatogonia and Sertoli cells. Just above the upper green arrow a large population of Leydig cells can be seen. These function comparatively normally, producing various androgens, including testosterone.
1. Amann R.P. 1993.Physiology and endocrinology. Chapter 77 in Equine Reproduction. Edited by A.O. McKinnon and J. Voss. Lea and Febiger.
