Prostate Gland Anatomy

Prostate gland is an exocrine gland that is found only in males. Exocrine glands are those that secrete their products, which may include chemical secretions, except hormones, into the duct glands.

Unlike endocrine glands, these glands don't secrete the hormones or chemical secretions directly into the blood stream, instead, they secrete their chemical secretions in the outside environment.

The prostate gland, consisting a glandular part and stroma, is located just below the urinary bladder and at the top of the penis. Its size is almost equal to that of a walnut. It surrounds the urethra, i.e., the tube through which urine passes from the bladder and is discharged out through the penis.

It is composed of fibrous tissues and some non-striped muscles. The urethra coming from the bladder and within the prostate is called prostatic urethra. The prostatic urethra fuses with the ejaculatory ducts in the urethra.

It is to be understood that passing of urine during the urination process and carrying semen during ejaculation, are the two functions of the urethra, in males.

The prostate is divided on the basis of zones and lobes. The zone classification has been specifically meant for medical purposes, wherein, the glandular functions of each part are considered to treat any complications. The anatomy is divided into four zones.

The outermost part is called peripheral zone (PZ) and it consists of 70% part of the normal prostate gland in an adult man. It is in the peripheral part that most times the prostate cancer occurs. The central zone (CZ) is nearly 25% of the normal gland.

The central zone surrounds the ejaculatory ducts and the prostate cancer in this region is more serious, and in many cases it may even affect the seminal vesicles. Seminal vesicles are structures attached to the vas deferens side of the urinary bladder.

Prostate gland and seminal vesicles, act as accessory sex glands and provide fluids that help in the nourishment of sperms. The third zone or the transitional zone accounts for 5% of prostate volume and this region is responsible for the prostate enlargement problems.

The last zone known as anterior fibro-muscular zone or stroma, doesn't contain any glandular parts, however, it consists of muscles and tissues. Based on the different zones, the doctors are able to classify the complications related to the prostate gland.

The anatomy is also majorly classified on the basis of lobes and it is divided into four parts - the anterior lobe, the posterior lobe, the lateral lobes (right and left), and the median lobe.'

Its chief function is the secretion of an alkaline fluid that forms a part of the seminal fluid ejaculated during the male orgasm. During this process, the muscular glands present in the prostate help the alkaline fluid, besides the sperm (produced in the testicles), pass into the urethra. The semen then ejaculates through the penis.

The alkaline fluid that is produced in the prostate gland constitutes 25 - 30% of the volume of the semen, besides the sperms and seminal vesicle fluid. The alkalinity of the fluid plays a crucial role in increasing the life span of the sperms.

How does the lifespan of sperms increase? Well, the vaginal tract of women contains acidic fluids, and the alkaline fluid that is a part of the semen helps in neutralizing the effect of the vaginal tract acids and hence, increases the life of the sperms.

A majority of men in older ages, are susceptible to prostate problems. Enlarged prostate and prostate cancer are the two common prostate complications in men. It is advisable for men above the age of 50, to get their prostate checked once in a year, so that its health is not affected negatively.