Prostate Gland

Prostate Gland

Human prostate gland weighs about 40 g. It consists of 20 to 30 separate glands, which open separately into the urethra. These glands are tubuloalveolar in nature. Epithelial lining of these glands is made up of columnar cells. Prostate secretes prostatic fluid, which is emptied into prostatic urethra through prostatic sinuses.

  • The prostate is a walnut-sized gland located between the bladder and the penis.

  • The prostate is just in front of the rectum.

  • The urethra runs through the center of the prostate, from the bladder to the penis, letting urine flow out of the body.

  • The prostate secretes fluid that nourishes and protects sperm. During ejaculation, the prostate squeezes this fluid into the urethra, and it’s expelled with sperm as semen


Prostate fluid is a thin, milky and alkaline fluid. It forms 30% of total semen.




Prostatic fluid provides optimum pH for the motility of sperms. Generally, sperms are nonmotile at a pH of less than 6.0. There are some factors, which decrease
the pH and motility of sperm both in vas deferens and
female genital tract.

In vas deferens
End products of metabolic activities in the sperm make the fluid in vas deferens acidic, so that the sperms are nonmotile.

In female genital tract

Vaginal secretions in females are highly acidic with a pH of 3.5 to 4.0. So, when semen is ejaculated into female genital tract at coitus, sperms are nonmotile initially.
However, the alkaline prostatic secretion, which is also present in semen neutralizes the acidity in vagina and maintains a pH of 6.0 to 6.5. At this pH, the sperms
become motile and chances of fertilization are enhanced.


The clotting enzymes present in prostatic fluid convert fibrinogen (from seminal vesicles) into coagulum. It is essential for holding the sperms in uterine cervix.


The coagulum is dissolved by fibrinolysin of prostatic fluid, so that the sperms become motile.


Enlargement of prostate gland is of two types:

1. Benign enlargement

2. Malignant enlargement.

1. Benign enlargement

Hyperplasia of glandular structures and connective tissues causes benign (nonmalignant) enlargement of
prostate gland. It occurs in some men after 60 years of age, due to unknown causes. Enlarged prostate gland stretches the urethra and obstructs urine outflow from bladder.

Common symptoms are increase in the frequency of urination, difficulty in urination, dribbling of urine after urination and occasional renal failure.

2. Malignant enlargement

Malignant enlargement (cancer) of prostate gland also causes obstruction of urinary passage. In addition, the metastasis (spread of cancer from primary site to other places) affects the other tissues, particularly bones.