The kidneys remove excess liquid and wastes from the blood in the form of urine, keep a stable balance of salts and other substances in the blood, and produce a hormone that aids the formation of red blood cells. Grab A Copy Click here
Narrow tubes called ureters carry urine from the kidneys to the bladder, a triangle-shaped chamber in the lower abdomen. Urine is stored in the bladder and emptied through the urethra.
Normal urine is sterile. It contains fluids, salts, and waste products, but it is free of bacteria, viruses, and fungi. An infection occurs when microorganisms, usually bacteria from the digestive tract, cling to the opening of the urethra and begin to multiply. Most infections arise from one type of bacteria, Escherichia coli (E. coli), which normally lives in the colon.
In most cases, bacteria first begin growing in the urethra. An infection limited to the urethra is called urethritis. Grab A Copy Click here
From there bacteria often move on to the bladder, causing a bladder infection (cystitis). If the infection is not treated promptly, bacteria may then go up the ureters to infect the kidneys (pyelonephritis).
Microorganisms called Chlamydia and Mycoplasma may also cause UTIs in both men and women, but these infections tend to remain limited to the urethra and reproductive system.
Unlike E. coli, Chlamydia and Mycoplasma may be sexually transmitted, and infections require treatment of both partners.
The urinary system is structured in a way that helps ward off infection. The ureters and bladder normally prevent urine from backing up toward the kidneys, and the flow of urine from the bladder helps wash bacteria out of the body.
In men, the prostate gland produces secretions that slow bacterial growth. In both sexes, immune defenses also prevent infection. But despite these safeguards, infections still occur.Grab A Copy Click here