Spermatogenesis is the production of sperms (n) by immature male germ cells (2n) at puberty inside the testis.
Hormonal role in spermatogenesis:
Spermatogenesis starts due to increase in secretion of GnRH (Gonadotropin Releasing Hormone) by hypothalamus. GnRH acts on Anterior pituitary gland and stimulates secretion of 2 gonadotropins – LH (Luteinizing Hormone) or ICSH (Interstitial Cell Stimulating Hormone) and FSH (Follicle Stimulating Hormone).
LH acts on Leydig cells for secreting testosterone and other androgens inturn stimulates process of spermatogenesis. FSH acts on sertoli cells which secretes some factors useful in spermiogenesis. Sertoli cells secrete inhebin that suppresses FSH synthesis.
It is production of haploid spermatozoa from diploid spermatogonia inside testis at puberty. At puberty, Spermatogonium undergoes mitosis forms 2 spermatogonia A and B. Both A and B are diploid with 46 chromosomes each. A: Function as mother spermatogonia. B : Grow in size to function as primary spermatocytes. They then undergo meiosis to form 2 haploid cells called secondary spermatocytes (23 chromosomes). They then undergo 2nd meiotic division forming 4 haploid spermatids. These spermatids are transferred into spermatozoa (sperms) by spermiogenesis. After spermiogeneses, sperm heads become embedded into Sertoli cells and are released from seminiferous tubules by process called spermiation.
