Question

Which organ in humans does the sperm production occur?

Answer 1

The male reproductive system is located in the pelvic region. Along with the primary and secondary sex organs, there are some accessory glands present namely, seminal vesicle, bulbourethral glands and prostate gland. Their secretion constitutes the seminal plasma, and provides nutrition and lubrication. The male external genitalia is penis, which is also the copulatory organ and has the specialized erectile tissue.

Complete answer:
- There is one pair of oval shaped testes situated outside the abdominal cavity within a pouch called scrotum which maintain $2 - {3^o}C$ lower than the normal body temperature which is required for spermatogenesis. Testes descend in the scrotum in the ${7^{th}}$ month of embryonic life through the inguinal canal.
- Each testis is divided into almost 250 compartments called testicular lobules. Each lobule has $1 - 3$ seminiferous tubules where sperms are produced. It also has interstitial or Leydig cells which synthesize and secrete testicular hormones, androgens. Seminiferous tubule in turn has two types of cells namely, male germ cells (spermatogonia) and Sertoli cells.
- Spermatogenesis: The process of formation of male gamete, sperm is called spermatogenesis. It starts at puberty due to significant increase in Gonadotropin (GnRH). The male germ cell, spermatogonia grow and mature and form primary spermatocytes or primary spermatogonia which are diploid ($2$n), then enters into the stage of reduction division, and forms two secondary spermatocytes after meiosis-I which are haploid (n). Each secondary spermatocyte forms $2$ spermatids (n) after meiosis-II.
- Finally, all four spermatids form spermatozoa (sperms-(n)) by the process called ‘spermiogenesis’. The sperm head is embedded in Sertoli cells and is finally released from the seminiferous tubule by the process called ‘spermiation’.
- Pathway of sperms: When released from seminiferous tubules, sperms reach to rete testis through Tubuli recti. From Rete testis the sperms reach vas efferens, then to epididymis followed by vas deferens. The epididymis temporarily stores sperms and the functional maturation of sperms takes place here. The sperms along with the secretion of accessory gland, seminal vesicle is now called semen, which reaches the urethra through the ejaculatory duct. The other accessory glands also release their secretion in urethra. The semen then goes outside of urethra by the process known as ejaculation.

Hence, the sperm production occurs in __ testes.

Note: The secretions of sex accessory glands include seminal plasma which is rich in fructose, $C{a^{2 + }}$, and certain enzymes. The secretion of these glands along with the sperms is called “semen”, which is slightly alkaline in nature.