The Urinary System: Description and Diseases

The human anatomy is a marvel of nature which consists of a skeleton made of bones and multiple organs, each designated with its own functions. Besides the various bones, joints and muscles, there are 11 main systems, each comprised of its own organs.

You may have read or heard about the nervous system (brain and spine), circulatory system (heart), respiratory system (lungs) and digestive system (stomach and intestines). Another system which evades much discussion is the urinary or excretory system. As depicted in the diagram above, it includes the kidneys, ureter, prostate, and bladder.


Also identified as the renal system or the urinary tract, the principal function of the structure is to dispose waste from the body and also to regulate the flow of blood. While the digestive system is responsible for the excretion of feces, the urinary system is in control of the urine discharge from the body.

Such is the mechanism of the human body that the urinary system works in tandem with the lungs and intestines to ensure that there is balance in the level of water and chemicals found in it. In fact, the average adult emits between 27 and 68 ounces of fluid. This is tantamount to 800 to 2000 milliliters per individual. This calculation is made under the assumption that they drink eight glasses of water daily. Furthermore, the urinary system also deals with the fluid which is lost to perspiration and respiration processes respectively.


The primary organ of the urinary system is the kidneys. A pair of bean-shaped organs, as shown above, they are located in proximity to the posterior wall of the abdomen. The left kidney can be found slightly higher than the right one since the liver on the right side is larger than that on the opposite side.

They are surrounded by a film of adipose which performs the dual functionality of supporting the kidneys and also safeguarding them from potential damage. Additionally, the kidneys carry out the filtration of metabolic waste, excessive ions and extraneous chemicals, all of which forms the urine.


The ureters are also evident in the given diagram. They are a pair of tubes which disseminate urine from the kidneys to the urinary bladder. Once the kidney completes the refining process, the ureters come in to play and transport the urine on to the bladder.

In terms of length, ureters are almost a foot long and they run parallel to each other on either side of the vertebral column. The urine is carried smoothly through the muscle tissue in the walls. The ureters extend on to the point of entry of the bladder where they are sealed by the ureterovesical valves. These valves also ensure that urine does not travel backward to the kidney.

Urinary Bladder

Speaking of the bladder, it has a sac-shaped appearance and is imperative for maintaining proper storage of urine. You may have heard people speak about having an active bladder in jest. This signifies the central function of the bladder. For instance, the more water you drink, the more urine will end up in your bladder.

Located along the body’s pelvic region, urine enters the bladder from the ureters and gradually fills the capacity of the bladder. This stretches the walls of the organ slowly as well. At any given point in time, the urinary bladder can hold between 600 to 800 milliliters of urine.


A tube which allows the passage of urine from the bladder to an external destination is the urethra. When a male individual releases urine, it is the urethra which secretes the urine, thus completing the urinating process, which begins from the kidneys all the way to the urethra.

The female urethra is only two inches long whereas the male organ is eight inches in length and ends at the edge of their genitals. Additionally, for the male, the urethra also delivers the sperm out of the body, which makes it a part of the male reproductive system.

The actual circulation of urine through the urethra is governed by the internal and external urethral sphincter muscles. These muscles open when the bladder full to the brim. This movement creates the sensation of wanting to urinate. The external part of the sphincter is made of skeletal muscle which opens when urine passes through.


Urinary tract infection

There are several issues which affect the urinary system. For instance, urinary tract infection (UTI) transpires when bacteria finds its way into the urinary tract. This makes the urethra, bladder and the kidneys susceptible. Occurring more regularly in women, urinary tract infections are generally treated with the consumption of antibiotics. In the United States, approximately eight million people develop such an infection each year, according to the American Urological Association (AUA).

High PSA

For men, prostate-specific antigen or PSA is a protein produced by cells of the prostate gland. This is normal and a standard measurement of PSA levels can determine if there may be an issue in the urinary system, such as prostate cancer, but a high PSA level can indicate many other conditions, some of which are not serious. A high PSA level might be considered even be considered normal for a particular individual. Only your urologist can make the appropriate determination.


A frequent disease of the urinary system is incontinence. This happens when individuals feel the need to urinate more often than usual. They may be required to urinate in the middle of the night which would result in the emptying of their bladder. This is courtesy of an enlarged prostate in the body and is common among our older population since the prostate tends to enlarge.

Interstitial cystitis

Also known as painful bladder system, it is a chronic condition which usually affects women. They experience considerable agony in their bladder, which is often accompanied by pelvic pain as well. If the case is severe, it can cause the bladder to develop scarring, which makes it less elastic as a consequence.

Kidney stones

The kidney is where the entire process begins and it is also prone to diseases, the most common of which are kidney stones. These are deposits of calcium oxalate which germinate in the urinary tract. When chemicals found in the urine are concentrated enough, they turn from liquid to solid form. These are called kidney stones. They cause excessive pain in the back and sides of the body. Blood may also appear sporadically in the urine. To treat the stone, patients may undergo minor therapy which disintegrates the stone with shockwaves or as the case with many patients, they will urinate them out.

Kidney failure

The final disease we will discuss is an extreme condition. Kidney failure or renal failure can be a temporary condition or become a permanent state of affairs. In case of the latter, the kidneys are unable to perform the filtration process. These may be caused by experiencing trauma or hypertension. Kidney failure requires the patient to undergo elaborate dialysis treatment and in the worst case scenario, a kidney transplant.

If you think you may have urinary problems, speak to your urologist or medical professional with equivalent expertise in this area. Don’t wait. Although the issue may not be serious, you will not know until you are diagnosed properly.

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