Updated by: Arabinda Naik
The male reproductive system of man consists of the
following parts.
1. Scrotum
2. Testis
3. Epididymis
4. Vas deferens
5. Ejaculatory duct
6. Urethra
7. Penis
8. Accessory glands
It is a pouch of deeply pigmented skin, having two
sacs containing one testis each. The normal temperature of the testis
in the scrotum is about 2 degree lower than the internal body
temperature the ideal temperature for developing sperm. The cavity
of the scrotum is connected with the abdominal cavity by inguinal
canal.
In man there are a pair of testis located in the pouch like
scrotum attached to the wall of scrotal sac by a small fold called
gubernaculum. Each testis is solid and oval in shape, measuring
about 4 cm in length and 10 gm weight. Each testis communicates
with the abdominal cavity by a narrow passage called inguinal canal.
It is held in position within the scrotal sac by means of a compact
cord called inguinal cord or spermatic cord.
A fibrous connective tissue layer called tunica albuginea covers the
testis. As many as 200 or more septa divide the testis internally into
compartments called lobules. In each lobules 1-3 much coiled
seminiferous tubules are present. These tubules are responsible for
formation of sperm. Internal epithelium of these tubules are formed
of germinal epithelial cells which undergo division to produce
spermatozoa. At place some large conical Sertoli are seen. They
provide nourishment to the developing sperm. Amongst the
seminiferous tubules cells of Leydig, blood vessel, nerves are
present in a loose connective tissue. Leydig cells secrete male sex
hormone called testosterone that controls the development in males.
The seminiferous tubules from the testis converge to form a rete
testis from which arise 15-20 thin ducts the vasa efferentia. All the
vasa efferentia unite to a single duct called epididymis.
Behind each testis is epididymis. It is a long coiled
tube of about 6 metres in length and partially encircled the testis. It
has three parts.
Caput epididymis: It is the top part connected with
the seminiferous tubules.
Corpus epididymis: It is the middle part
connected with the seminiferous tubule.
Cauda epididymis: It is
the bottom part connected with vasa deferens.
Epididymis serves as a duct for the passage of sperms from
testis to vas deferens. It stores sperms.
it is muscular tube which leaves the base of
epididymis on each side of the scrotal sac through a passage called
inguinal canal to enter into the abdominal cavity. The sperms are
carries by vasa differentia to be discharged at the time of ejaculation.
It is a short duct formed by the union of
vas deferens and the duct of the seminal vesicle. The ejaculatory duct
of both the sides open into the urethra.
The urethra originates from the urinary bladder and
travels through the penis and opens to the outside at its tip. It serve
as a common passage for the flow of urine and semen.
It is cylindrical, muscular erectile organ for transfer of
semen from male organs into the vagina for the female. It has three
elongated tissues lying side by side and bound by connective tissue
and covered by loose skin. The tissues are two upper corpora
cavernosa and one ventral corpus spongiosum. At center urethra is
present. The enlarged tips with genital orifice is called glans penis.
It is covered by a fold of skin called prepuce.
Semen is a collection of secretion from the seminal
vesicles, prostate glands and cowper’s gland and sperms from
testis. It has an alkaline which protects the sperm from the acidity of
the vagina. When the penis is erect, semen is ejected from the penis
during ejaculation.
These are two muscular pouch like
structure lying between the urinary bladder. They secrete a thick
fluid. It contains nutrients like fructose, vitamins, mucus and large
amount of prostaglandins for the nutrition and protection of sperm.
Behind the urinary bladder another
hard muscular structure is present. It is prostate gland. It is encircles
the ejaculatory duct and urethra. A thin, milky with alkaline
secretion from prostate neutralizes acidity in the seminal fluid.
Below the prostate are two pea sized glands which open into urethra at the base of the
penis. Its alkaline secretion neutralizes acidity, protects the sperms
and lubricates vaginal wall of the female for easy penetration of the
penis.