It is known to all that all living creatures reproduce as a result of natural instinct. The man reproduces through special reproduction system comprising different internal and external organs which is known as human reproductive system. The male reproductive system organs comprise two testes, seminal vesicle, tubes carrying semen, prostate glands, and external genitals, namely scrotum or the outer sac for testes, and the penis. The female reproductive organs comprise two ovaries, two tubes, uterus, vagina, vulva and clitoris.
The testes are the main reproductive organs of male, as these produce the spermatozoa. The spermatozoa are the cells which fertilize the ovum of the female and produce what is known as a zygote ultimately develops into a foetus. The oval shaped two numbers of testes lie in a sac called scrotum.
The sperms, thus produced by the testes are carried by two tubes known as spermatic cords and are stored into two elongated shaped structures called seminal vesicles till the time of ejaculation. The vas deferent duct which is the latter part of the spermatic of a male reproductive system receives the connecting tube from the seminal vesicle and goes further to meet the urethra. The urethra is the tube that also carries urine from the urinary bladder, passing through a gland called prostate gland. The urethra continues through the length of the penis. The seminal fluid is composed of spermatozoa from the seminal vesicle and the fluid from the prostate gland. Each ejaculation of the seminal fluid contains about two hundred million spermatozoa. But only one spermatozoon is sufficient to fertilize the female ovum. A spermatozoon has a head, neck and a tail. the penis consist of the tip known as glans where the urethra opens, the neck and the root of penis. The penis is covered by a skin called the prepuce on the glans. So during coition, the copulatory act results in the discharge of the seminal fluid and the spermatozoa are deposited in the female genitalia.The perineum is the region where the external geitalia and the anus are located.
The scrotum is a sac which is lined on the outside by skin. There is a layer closely united to the skin, that of smooth muscle which constitutes the dartos muscle. Contraction of the muscle produces corrugations on the skin and makes it tight. The scrotum consist of two halves, right and left that are separated from one another by a septum. Each half of the scrotum contains the corresponding testis, epididymis, and the initial parts of the ductus deferens.
Each testis of the male reproductive system is an oval shaped structure about 4 cm in its vertical diameter. It is about 2.5 cm broad and about 3 cm in anterioposterior diameter. The two testes lie in the scrotum and placed obliquely the upper pole being slightly anterior and lateral to the lower pole.
The left testis is somewhat lower than the right one. The surface of the testis is divided into medial and lateral surfaces which are separated by anterior and posterior borders. The anterior border is rounded there being no definite demarcation between the medial and lateral surfaces. The epididymis is attached to the posterior border. The epididymis is a mass formed by tortuous tubules. Upper end of it lies near the upper pole of the testis, which is enlarged and called the head. The middle part of the epididymis is called the body and the thin lower part is called the tail. The testis and epididymis lie in a closed sac which is called the tunica vaginalis. The wall of the sac is formed by a thin membrane similar peritoneum structure. At the posterior end of the lateral surface of the testis the visceral layer, which is reflected on to the medial aspect of the body of epididymis is called the sinus of the epididymis . Deep to the visceral layer of the tunica vaginalis , the outer most layer of the testis is formed , which is called tunica albuginea. In the posterior part of the testies the connective tissue forming the tunica albuginea is thicker than in another place and projects into into the substance of the testis, which is called the mediastinum testis. several septa pass from the medistinum testis to the tunica albuginea. It divide the substance of the testis into large number of lobules. Each lobule contains one or more highly intricate seminiferous tubules. Each testis has about 200 lobules, and that each lobule has one to three seminiferous tubules. The total number of tubules is between 400 and 600. Near the apex of the lobule the seminiferous tubules lose their complexity and join one another to form about twenty to thirty larger straight tubules. These enters the fibrous tissue of the mediastinum testis. These are unite to form a network called the rete testis of the male reproductive system. At the upper end of the rete testis gives of 12 to 20 efferent ductules. These ductules passes from the upper part of the testis into the head of epididymis. At the lower end of the head of the epididymis these tubules end in a lone tube namely the duct of the epididymis.
From the upper pole of the testis the spermatic cord extends through the inguinal canal, to the deep inguinal ring. The spermatic cord has a number of coverings, those are: – 1) Internal spermatic fascia which is the inner most covering and derived from the fascia transversalis. 2) Cremasteric fascia is the next covering which is derived from the internal oblique muscle of the abdomen and made by partly muscular and partly fibrous. 3) External spermatic fascia is the outermost layer, which is a continuance of the aponeurosis of the external oblique muscle of the abdomen.
In the male reproductive system the penis consist of a root that is fixed to the perineum, and the free part which is called corpus. The free part is lined all round by the skin. The apical part of the penis is enlarged and conical call the glans penis. The glans penis has a projection of posterior margin which is called by corona glands. The penis shows a slight constriction immediately proximal to the corona is called the neck of the penis. The skin covering the penis is loosely attached except over the glans. Over the glans it is firmly attached to the underlying tissue. The glans is also covered by a fold called the prepuce which extends from the neck of the penis towards the tip. Prepuce is attached by its posteroinferior part to the adjoining part of the glans by a fold called the frenulum. The space between the surface of the glansand the prepuce is called the preputial sac. The surface of the penis that is continuous with a anterior abdominal wall is called the dorsum. The surface towards the scrotum is the ventral surface.
The prostate of male reproductive system is a glandular structure. It lies in the space between the lower end of the urinary bladder and upper surface of the urogenital diaphragm. It lies behind the lower part of the symphysis pubis and in front of the rectum. The prostate is traversed by the prostatic part of the urethra, and the ejaculatory duct. The prostate is broadest above and narrowest below. The prostate is surrounded by a fibrous capsule which is closely adherent to the gland. There is a fibrous sheath which is a part of pelvic fascia outside of the capsule. The posterior part of the fibrous sheath, which separate the prostatefrom the rectumis formed by the rectovesical fascia. The surface of the prostate consist of glandular tissue, masses of which are separated by fibromuscular septa. The glandular tissue is developed a little at birth and gradually grows. This growth becomes much faster at the time of puberty. After the age of about fifty years the prostate may undergo atrophy or in some case benign hypertrophy.