THE MALE REPRODUCTIVE SYSTEM CLASS 12

 Human Reproduction:

• As you are aware, humans sexually reproducing and viviparous. The reproductive events in humans include formation of gametes (gametogenesis), sperms in male and ovum in females; transfer of sperms into the female genital tract (insemination) and fusion of male and female gametes (fertilisation) leading to formation of zygote. The is followed by formation amd development of blastocyst and its attachment to the uterine wall (implantation), embryonic development (gestation) and delivery of the baby (parturition). 

 The Reproductive Events In The Male And   In The Female:

• Sperm formation continues even in old men, but formation of ovum ceases in women around the ge of fifty years. 

The Male Reproductive System 

• The male reproductive system is located in the pelvis region. It includes a pair od testes alongwith accessory ducts, glands and the external genitalia.

• The testes are situated outside tge abdominal cavity within a pouch called scrotum. The Scrotum helps in maintaining the low temperature of the testes (2-2.5° C lower  than the normal internal body temperature ) necessary fo spermatogenesis. In adults, each testis is oval in shape, with a length of about 4 to 5 cm and a width of about 2 to 3 cm. The testis is covered by a dense covering. Eacg testis has about comcompartments called testicular lobules.

Each lobule contains one to three highly coiled seminiferous tubules in which sperms are produced. Each seminiferous tubule is lined on its inside by two types of cells called male germ cells (spermatogonia) and Setlrtoli cells.

The male germ cells undergo meiotic divisions finally leading to sperm formation, while sertoli cells provide nutrition to the germ cells. The regions outside to the seminiferous tubules called interstitial spaces, contains small blood vessels and interstitial cells or Leyding cells. 

Leyding cells synthesise and secrete testicular hormones called androgens. Other immunologically competent cells are also present.

The male sex accessory ducts include rete testis,  vasa efferentia, epididymis and vas deferens . The seminiferous tubules of tge testis open into the vasa efferentia through rete testis. The vasa efferentia leave the testis open into the vasa epididymis located along the posterior surface of each testis. The epididymis leads to vas deferens that ascends to the abdomen and loops over the urinary bladder. It recives a duct from seminal vesicle and open into urethra as the ejaculatory duct. These ducts store and transport the sperms from the testis to the outside trough urethra. The urethra originates from the urinary bladder and  extends through the penis to its external opening called urethral meatus. 

The penis is the male external genitalia. It is made of special tissue that helps in erection of the points to facilitate insemination. The eblarged end of penis called the glans penis is covered by a loose for of skin called foreskin.

The male accessory glanda include paired seminal vesicles, a prostate and paired bulbourethral glands. Secretions of the glands constitute the seminal plasma which is rich in fructose, calcium and certain enzymes.The secretions of bulbourethral glands also helps in the lubrication of the penis.