Urinary System

This is Medical Terminology Unit 12 of 17. (Previous - Medical Terminology Unit 11 of 17: Respiratory System)

This unit discusses the Urinary System.

Unit Objectives

Urinary System Anatomy

The primary function of the urinary system is to maintain the volume and  levels of  body fluids within normal limits by excreting waste. 

The urinary system consists of:

  • Two kidneys
  • Two ureters
  • Urinary bladder
  • Urethra

The kidneys are bean-shaped organs, each about the size of your fists. They are located near the middle of the  back, just below the rib cage. Inside each kidney about a million tiny structures called nephrons filter blood.  They remove waste products and extra water, which becomes urine. The urine flows through tubes called ureters to the bladder, which stores the urine until it is passed through the urethra. The urethra is a canal extending from the bladder to the outside for the discharge of urine.

The kidney has several important functions that include: the elimination or organic waste, regulation of homeostasis in the body, regulation of acid-base balance, regulation of RBC production, regulation of blood pressure, some influence over blood glucose and blood amino acids, elimination of toxic substances and they act as endocrine glands.

Although the urinary system has a major role in excretion, there are other organs that assist in the excretion of waste products. Two examples are the lungs - when they rid the body of carbon dioxide and water and the skin excreting waste through the sweat glands.

The Bladder

The bladder is a hollow organ in your lower abdomen that stores urine. Some of the common conditions that can affect bladder function are identified here.

  • Cystitis is an infection in the urinary bladder. Acute cystitis occurs when the lower urinary tract (urethra and bladder) become infected by a bacteria.  E. coli, a bacteria found in the intestine. Cystitis is rare in men.

  • Urinary Tract Infection: UTIs are the second most common type of infection in the body. Symptoms include: pain or burning when urinating, fever, tiredness or shakiness; frequency (urge to use the bathroom often), pressure in your lower belly, urine that smells bad or looks cloudy or reddish and sometimes nausea or back pain. Treatments include medications.

  • Urinary incontinence refers to the loss of bladder control.

  • Interstitial cystitis is a chronic problem in which the bladder wall can become inflamed and irritated, leading to frequent, painful urination.

Diagnostic tests  include urine tests, x-rays and examination of the bladder wall with a scope called a cystoscope. Treatment varies depending on the cause of the problem. It may includes medications and in severe cases, surgery.

Bladder Cancer

Bladder cancer occurs in the lining of the bladder. It is the sixth most common type of cancer in the US. 

Risk Factors:

  • Smoking is a major risk factor for bladder cancer
  • Exposure to chemicals in the workplace
  • Family history of bladder cancer
  • Older, white males

Symptoms include:

  • Blood in your urine
  • Frequency
  • Painful urination
  • Low back pain

Treatments for bladder cancer include surgery, radiation, chemotherapy and biologic therapy. Biological therapies use the body's immune system, either directly or indirectly, to fight cancer or to lessen the side effects that may be caused by some cancer treatments.

Kidney Stones

A kidney stone, is a solid piece of material that forms in the kidney from substances in the urine.  It may be as small as a grain of sand or as large as a pearl.  Most kidney stones pass out of the body without assistance from a physician.  But sometimes medical intervention is necessary when the stone blocks the flow of urine and causes great pain.

Symptoms include:

  • Extreme pain in your back or side that will not go away
  • Blood in your urine
  • Fever and chills
  • Vomiting
  • Urine that smells bad or looks cloudy
  • Burning when urinating

This condition is called nephrolithiasis.

Lithotripsy is a medical procedure that uses shock waves to break up stones in the kidney, bladder, or ureter.  After the procedure, the tiny pieces of stones pass out of your body in your urine.  The most common type of lithotripsy is Extracorporeal shock wave lithotripsy (ESWL).  Extracorporeal means outside the body.  High-energy shock waves, also called sound waves, pass through the body until they hit the kidney stones.

Kidney Disorders and Diseases

Kidney diseases are also referred to as Renal diseases.  Inside each kidney tiny structures called nephrons filter blood and remove waste products and extra water. Damage to the nephrons results in kidney disease and may leave the kidneys unable to remove wastes. Usually the damage occurs slowly over years. There are no obvious symptoms.

Several conditions can cause kidney damage. You are at risk if you have diabetes, high blood pressure, or if a close family member has kidney disease.

Diabetic Nephropathy

The high blood glucose (sugar) levels associated with diabetes can damage your kidneys over time. The kidneys act as filters that clean your blood. When they are damaged, the waste and fluids build up in the blood and the body has no way to rid itself of the waste products. Kidney damage from diabetes is called diabetic nephropathy. An early sign is having small amounts of protein in your urine which can be detected by a urine test. A blood test can also help determine how well the kidneys are functioning. 

Kidney failure is also called End Stage renal disease, ESRD, or Renal failure. This condition occurs when your body cannot rid itself of harmful wastes, the blood pressures rises, the body retains excess fluids ,and the body does not make enough red cells.

Renal Dialysis

Renal Dialysis is another treatment for kidney failure. There are two main types of dialysis:  hemodialysis and peritoneal dialysis. Both types filter the blood to rid your body of harmful wastes, extra salt and water.  Hemodialysis requires a machine. Peritoneal dialysis uses the lining of your abdomen, to filter your blood.

Treatment  for kidney failure also includes a kidney transplant. A transplant is an operation that places a healthy kidney into a patient. The transplanted kidney takes over the work of the two kidneys that have failed.

During the transplant, the surgeon places the new kidney in your lower abdomen and connects the artery and vein of the new kidney to your artery and vein. Often, the new kidney will start making urine as soon as blood starts flowing through it; sometimes it takes a few weeks to start working.

Kidney Transplants

Kidney transplants are one of the most common transplant operations in the United States.

One donated kidney is needed to replace the work previously done by two.

The donated kidney may be from:

  • A living related donor
  • Living unrelated donor
  • Deceased donor

Wilm's Tumor

Wilms’ tumor is a rare type of kidney cancer that affects children.  It is also referred to as Nephroblastoma.  It causes a tumor on one or both kidneys.  Having certain genetic conditions or birth defects can increase the risk of developing Wilms’ tumor.  Children at risk should be followed every three months.

Symptoms include a lump in the abdomen and blood in the urine. 

The tumor is usually diagnosed and removed in surgery.  Other treatments include chemotherapy, radiation, biologic therapy or a combination.  Most children with Wilms’ tumor can be cured.

Kidney Cancer

Kidney cancer forms in the lining of tiny tubes inside your kidneys.  It happens most often in people over 40. 

Risk factors include:

  • Age over 40
  • Having certain genetic conditions
  • Misusing pain medicine

Symptoms include:

  • Blood in your urine
  • A lump in your abdomen
  • Unexplained weight loss
  • Pain in your side
  • Loss of appetite

Treatment  depends on your age, your overall health and how advanced the cancer is. It could include:  surgery, radiation, chemotherapy or biologic therapy.

Kidney cancer is also referred to as renal cancer.

Urinary System Combining Forms

Word Part   Meaning   Key Term
Cyst/o   bladder    cystoscopy
Lith/o   stone   lithotripsy
Meat/o   meatus   meatotomy
Nephr/o   kidney   nephritis
Ren/o   renal   renography
Ureter/o   ureter   ureterectomy
Urethr/o   urethra   urethritis

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