Mitch Medical Healthcare

What is the prostate gland and what does it do

The prostate gland is actually not a single gland. It is comprised of a collection of glands that are covered by a capsule. A gland is a structure or organ that produces a substance used in another part of the body. The prostate gland lies below the bladder, encircles the urethra, and lies in front of the rectum. Because it lies just in front of the rectum, the posterior aspect of the prostate can be assessed during a rectal examination. The normal size of the prostate gland is about the size of a walnut (Figures 1 and 2).

The prostate gland is divided into several zones, or areas.

The prostate gland is divided into several zones, or areas. These divisions are based on locations of the tissue, but they also have some significance with respect

Kidney

Ureter

Bladder

Prostate Urethra

Testis

Kidney

Ureter

Bladder

Prostate Urethra

Testis

Figure 1 Anatomy of the male genitourinary system.

From Prostate and Cancer by Sheldon H.F. Marks. Copyright © 1995 by Sheldon Marks. Reprinted with permission of Perseus Books Publishers, a member of Perseus Books, LLC.

Figure 1 Anatomy of the male genitourinary system.

From Prostate and Cancer by Sheldon H.F. Marks. Copyright © 1995 by Sheldon Marks. Reprinted with permission of Perseus Books Publishers, a member of Perseus Books, LLC.

Symphysis pubis (Pubic bone)

Vas deferens

Urethra Corpus cavernosum Corpus spongiosum

Glans penis Epididymis

Symphysis pubis (Pubic bone)

Vas deferens

Urethra Corpus cavernosum Corpus spongiosum

Glans penis Epididymis

External urethral sphincter

Testis

Figure 2 Anatomy of the male genitourinary system.

Ureter

Urinary bladder Rectum Seminal vesicle Ejaculatory duct

Prostate

External urethral sphincter

Testis

Figure 2 Anatomy of the male genitourinary system.

to benign prostatic hypertrophy (BPH) and prostate cancer. The zones are the transition zone, the peripheral zone, and the central zone (Figure 3). In most prostate cancers, the tumor occurs in the peripheral zone. In a few cases, the tumor is mostly located in the transition zone, around the urethra or toward the abdomen. In 85% of patients, the prostate cancer is multifocal, meaning that it is found in more than one area in the prostate. Seventy percent of prostate cancer patients with a palpable nodule, one that can be felt by a rectal examination, have cancer on the other side also. Another way to describe the prostate gland is to divide it into lobes. The prostate gland has five lobes: two lateral lobes, a middle lobe, an anterior lobe, and a posterior lobe. Benign (noncancerous) enlargement of the prostate typically occurs in the lateral lobes and may also affect the middle lobe.

The prostate gland contributes substances to the ejaculate that serve as nutrients to sperm. The prostate gland has a high amount of zinc in it. The reason for this is not clear, but it appears to help in fighting off infections.

Abdomen

The part of the body below the ribs and above the pelvic bone that contains organs such as the intestines, the liver, the kidneys, the stomach, the bladder, and the prostate.

Multifocal

Found in more than one area.

Palpable

Capable of being felt during a physical examination by an experienced doctor. In the case of prostate cancer, this refers to an abnormality of the prostate that can be felt during a rectal examination.

Benign

A growth that is not cancerous.

The prostate gland in the adult male is normally about 20 to 25 cm3 in size.

Benign prostatic hyperplasia (BPH)

Noncancerous enlargement of the prostate.