Benign prostatic hyperplasia.

Anatomy and Physiology The prostate is a pyramidal-shaped fibromuscular and glandular accessory sex organ that lies retroperitoneally encircling the bladder neck. It is composed oftwo distinct types of glandular elements-the inner periurethral glands, which are responsible for the hyperplasia of BPH, and the external glands, which are the site of neoplastic degeneration. The secretions (seminal plasma) of the prostate and other sex accessory glands (epididymis, vas deferens and seminal vesicles) constitute most of the volume and chemical components of the ejaculate. This fluid has a high concentration of zinc, potassium, citric acid, fructose and prostaglandins and contains a variety of proteins including proteolytic enzymes and immunoglobulins. These substances are thought to provide optimal conditions for sperm motility and survival in the male and female reproductive tracts, and probably also play a role in protecting the male genitourinary tract from infection.