Urinary Tract

The structure of the urinary tract includes: the kidneys, two ureters, (tubes leading from the kidneys to the bladder,) and the urethra, a tube leading from the bladder to the exterior of the body. The urinary tract is a little like a plumbing system, with special pipes that allow water and salts to flow through them. The kidneys make up a filter system for the blood, reabsorbing almost 99%% of the fluid into the blood, and sending only two to four pints of waste (urine) into the bladder for storage until it can be disposed of. The kidneys allow the blood to keep glucose, salts and minerals after cleansing it of poisonous materials which will be passed out in the urinary tract. Urine is produced in the kidneys and trickles down twenty-four hours a day through two ten to twelve inch long tubes called ureters, which connect the kidneys to the bladder. The ureters are about one-fourth inch in diameter and their muscular walls contract to make waves of movement to force the urine into the bladder. The bladder is expandable and stores the urine until it can be conveniently disposed of. It also closes openings into the ureters so that urine cannot flow back into the kidneys. The tube through which the urine flows out of the body is called the urethra. Did you know that less than half of one single kidney can do all the work that two kidneys usually do?