Fig. 3.

Main functions of the efferent ductules, the epididymal duct, and the vas deferens. The Sertoli cells secrete a fluid in the lumen of seminal tubules which converge towards the rete testis (R); about 90% of it is reabsorbed by the non-ciliated epithelial cells of the efferent ductules (in purple), leading to a concentration of spermatozoa. These are then transported into the epididymal duct where some of the epithelial cells contribute to the creation of a new intraluminal fluid that bathes the spermatozoa (Sp.). These cells are also at the origin of the sperm maturation process. Sperm are continuously produced in the epithelium of the seminal tubules and are stored in the tail of the epididymal duct. Part of this stock is mobilized during ejaculation (emission phase) and propelled into the vas deferens, where the layers of smooth muscle cells enable these spermatozoa to be rapidly transported into the posterior urethra via the ejaculatory duct. Gray dotted highlighting indicates structures that, in addition to the vas deferens, may be absent in CAVD. SV seminal vesicle