The male reproductive system comprises of the following:
- a pair of testes, organs that produce the male gametes i.e., sperms
- a network of tubules and tubes for passage of the sperms called the duct system
- associated glands
- a mating organ called the penis.
Testes
The male reproductive system comprises of a pair of testes that are present in a thin-walled sac called the scrotum. The scrotum is contained within the abdominal cavity in the embryonic stage. Shortly before birth, they come down and remain outside throughout life. This is because the testes cannot produce sperms at the body temperature. A temperature 2-3 degrees lower is ideal for the production of sperms. The scrotal sacs hang loose when it is hot and when it is cold the skin of the scrotal sacs contracts and this keeps them in close contact with the body.
Each testis is covered by a thick connective tissue layer. Internally, the testis is lobed. There are 15-20 lobes, each having a network of seminiferous tubules and the interstitial cells between the tubules.
The seminiferous tubules produce sperms that are passed along the tubules to the posterior region of the testis. The sperms are produced by a process called the spermatogenesis. The interstitial cells are also called the Leydig cells and they secrete the hormone testosterone. In addition they also form a packing tissue between the seminiferous tubules.
Duct System
From the seminiferous tubules, the sperms are passed into a network of 10-12 ducts called the efferent ducts or the vasa efferentia. They are then passed into a highly coiled tubular part called the epididymis. Epididymis is an organ that extends from the top of the testis along its side to its back. It therefore, has three parts - head (upper), body (middle) and tail (hind). It temporarily stores the sperms.
The sperms from the epididymis pass into a distinct tube called the vas deferens, also called the sperm duct. Vas deferens is also coiled though not much. It rises into the abdominal cavity and loops over the ureter of that side. The passage that connects the testicular region with the abdomen is called the inguinal canal. Sometimes, the intestine bulges into the scrotum through this canal due to pressure in the abdomen. This causes hernia. Vas deferens is joined by the duct from the seminal vesicle to form the ejaculatory duct. The duct then passes through the Prostateglands and opens into the urethra. The system of tubules consisting of the vasa efferentia, epididymis, vas deferens, ejaculatory tube and the urethra is the duct system associated with the male reproductive system.Glands
The various glands associated with the male reproductive system are as follows:
- Seminal vesicles
- Prostategland
- Cowper's glands
- Penis glands
Seminal Vesicles
A pair of seminal vesicles are glands that are present behind the urinary bladder. Each sperm duct has the seminal vesicle of its side secreting a fluid into the common ejaculatory duct. This fluid along with the sperms is called the semen, a milky fluid.
Prostate Gland
It is a bi-lobed gland near the opening of the urethra. The prostate gland also pours its secretion into the urethra. It is alkaline and mixes with the semen.
Cowper's Glands
They are a pair of small ovoid glands that secrete lubricating fluid into the urethra just before it enters the penis.
The secretions of these glands make the sluggish sperms more active and help in the passage of sperms through the duct system and then in the ejaculation.Penis
Penis is a muscular organ containing erectile tissue. The tissue is richly supplied with blood vessels. On sexual stimulation the penis is gorged (supplied) excess with blood which causes it to become erect. During sexual intercourse, the penis is inserted into the vagina of the females before ejaculation. Ejaculation is the release of sperms by the penis to the outside.
