1 GOAT SEMEN COLLECTION AND PROCESSING BY DR. LOUIS ...

sometime before sexual differentiation. In the fetus and young male, the gonocytes are contained
inside the seminiferous tubules. These multiply and after birth give spermatogonia. The quantitative
efficiency of spermatogenesis depends to a great extent in the manner in which these divisions take
place. The cells originating from the last spermatogonial division are the primary spermatocytes.
Meiotic division of these result in the production of daughter cells, the secondary spermatocytes.
The secondary spermatocytes divide and form spermatids which undergo a complex series of
changes (spermiogenesis) resulting in the spermatozoa. The quality of the spermatozoa produced
depends to a great extent on this complex metamorphosis which occurs in the seminiferous
epithelium but undergoes completion in the epididymis. The various germ cells are located in the
seminiferous epithelium, whose structure is maintained by the Sertoli (nurse) cells (see Figs. 1 and
2). The two major functions of the testis include androgen synthesis by the interstitial cells (Leydig)
and sperm production within the seminiferous tubules. Although these two functions are separated
anatomically, intercellular communications exist between them.
FIGURE 1: Hypothalamus
2