The Prostate Gland: Anatomy and Function

Before you can understand the symptoms and implications of prostate problems, it is first necessary to take a look at the workings of the male urinary system.

The prostate gland is situated beneath the bladder (more precisely, just beneath the neck of the bladder). It's not to be confused with the urethra which evacuates the urine from the bladder, or the ureters which take the urine from the kidneys to the bladder. The prostate comprises three lobes: a right and left lobe, and a central lobe, located at the back beneath the neck of the bladder.

The Role of the Sphincters

Close to the prostate are two muscles called sphincters. These muscles control the bladder and regulate the flow of urine. They also assist in expeling the semen during orgasm. The muscle below the prostate, known as the external bladder sphincter, is of prime importantance in preventing urine leaking from the bladder.

In the case of the prostate being surgically removed, the striated sphincter of the urethra remains in place enabling the retention of urine. However, under certain conditions, this sphincter becomes weak, resulting in post-operatory incontinence.

Behind the prostate are found the seminal vesicles which collect the sperm in between ejaculations. They are connected to the ejaculation ducts which cross the prostate and empty into the urethra. These ejaculation ducts are integral with the prostate and thus, if the prostate is completely removed, they will have to be sectioned. This surgery therefore renders the patient sterile.

The Bladder is a Reservoir

The bladder collects the urine produced by the kidneys ansd stores it in between urinations. Its ability to store urine depends upon its elasticity. The bladder walls are comprised of muscular fibres (detrusor) which expand as necessary as the bladder fills up. At a certain volume these reflexes reverse and a contraction is triggered. It's at this point that one feels the need to urinate. The striated sphincter opens and urine can then flow. The jet of urine quickly increases in force then diminishes as the bladder becomes empty.

The Kidneys Filter

We have two kidneys which remove toxic waste from the blood. This waste is then eliminated in the urine. The most well-know waste is urea. A build-up of urea in the blood indicates kidney insufficiency or failure. Too high a level of urea in the blood can cause problems with consciousness, leading to coma.

The Prostate - a Gland and a Muscle

The prostate is a small gland, about the size of a horsechestnut or walnut, which only exists in men. It produces secretions which are part of sperm. That is its only function. Unlike the liver (which is required in order to live) the prostate isn't an essential gland. It can therefore be removed under circumstances without danger to life.

Problems related to the prostate tend to arise due to its anatomical location which means that its removal can often cause urinary or sexual problems.

A Sick Prostate

There are three basic types of prostate illness:

• Prostatitis or infection of the prostate.
  
  
• Adenoma or benign hypertrophy (often referred to as BPH). This is the commonest and implies a non-cancerous tumour causing enlargement of the prostate.
  
  
• Cancer. A scurge as recently as 15 years ago, but now increasingly well checked by modern methods of detection and treatment. This is a malignant tumour of the prostate.

There are thus two types of prostate tumours:

• the first, benign: adenoma
  
  
• the second, malignant: cancer

The Central and Peripheral Prostate

So as to better comprehend these two ailments and their symptoms, it's necessary to understand the makeup of the prostate. The prostate is composed of two parts:

• The central prostate (sometimes known as the cranial prostate or transition zone) which surrounds the urinary duct, which compresses the prostate as urine volume increases. It's in this region that adenoma develops. This has nothing to do with cancer and is never cancerous.
  
  
• The peripheral prostate (sometimes known as the caudal prostate or peripheral zone) which surrounds the central prostate. It is here that cancer can arise, never adenoma.