Question

Describe in brief the male reproductive system of humans.

Answer 1

The reproductive events in human males include formation of sperms and transfer of sperms i.e insemination. For successful occurrence of these events some specialized organs and ducts are present that make the male reproductive system.

Complete answer:
- In human beings the male reproductive system consists of a pair of testes with accessory ducts, glands and the external genitalia. The testes remain inside a sack like structure called scrotum which is positioned outside the abdominal cavity. Each testis is oval in shape, and is covered with a compact covering. Inside testes highly coiled masses of tubes are present that are called seminiferous tubules.
- Each seminiferous tubule contains two types of cells – the male germ cells spermatogonia and Sertoli cells. The male germ cells produce sperms through the process of spermatogenesis, while Sertoli cells provide nutrition to the germ cells. Outside the seminiferous tubules are present interstitial spaces that contain small blood vessels and Leydig cells. Testicular hormones called androgens are synthesized and secreted by Leydig cells.
- The seminiferous tubules of the testis open into a duct called vasa efferentia. The vasa efferentia opens into the epididymis that is a long coiled tube situated on the backside of each testis. The epididymis opens into a long, muscular tube known as vas deferens. The vas deferens continues into the pelvic cavity and forms a flask shaped structure called ampulla towards the posterior side of the urinary bladder. Here it receives a duct from the seminal vesicle and opens into urethra.
- The paired seminal vesicles secrete a fluid that is rich in fructose and is used by the sperms mitochondria to generate ATP required for their movement. The urethra originates from the urinary bladder and passes through the penis to its external opening called urethral meatus. The male external genital organ, penis is composed of specialized tissue which helps in its erection to facilitate insemination.
- The cone shaped end of penis is called the glans penis that remains covered with a loose fold of skin called foreskin. Paired seminal vesicles, prostate gland and paired bulbourethral glands are important male accessory glands. The prostate gland secretes an alkaline milky fluid that makes the seminal fluid somewhat thicker and after this addition the seminal fluid is called as semen. The two bulbourethral glands secrete a thick, salty fluid that is finally added to the semen and that lubricates the end point of urethra.

Fig: Male reproductive system in humans

Note: The scrotum is located outside the abdominal cavity behind the penis that helps in maintaining the low temperature of the testes (about 2 - 2.5°C lesser than the internal body temperature) that is necessary for production and development of sperms.