Muscles in the ureter walls continually tighten and relax forcing urine downward, away from the kidneys. If urine backs up, or is allowed to stand still, a kidney infection can develop. About every 10 to 15 seconds, small amounts of urine are emptied into the bladder from the ureters. This triangle-shaped, hollow organ is located in the lower abdomen. It is held in place by ligaments that are attached to other organs and the pelvic bones. The bladder's walls relax and expand to store urine, and contract and flatten to empty urine through the urethra.
The typical healthy adult bladder can store up to two cups of urine for two to five hours. Upon examination, specific "landmarks" are used to describe the location of any irregularities in the bladder. These are:. Two sphincter muscles. These circular muscles help keep urine from leaking by closing tightly like a rubber band around the opening of the bladder. Nerves in the bladder. Most people are born with two that are located in the back of the abdominal cavity just above the waist and along the spinal column.
In adults, each kidney is fist-sized and shaped like a bean. Via arteries and veins, the kidneys are connected to the body's vascular blood system. Whatever is not needed is filtered through and eliminated as urine. Urine exits the kidney through a long narrow tube called the ureter. The ureter exits into the bladder. It is in this ureter where kidney stones can get stuck. During pregnancy, the fetus can obstruct the ureter since it is located close to the growing fetus.
After the urine travels down the ureters, it enters the bladder, a stretchy pouch surrounded by muscle located just above your pelvis. The bladder's main job is to hold urine. As it gets full, you begin to feel the need to urinate.
When you urinate, the smooth muscle of the bladder walls contract, releasing the urine. In women, the bladder sits on top of the front wall of the vagina.
As women age, the bladder can fall or slip out of place cystocele because the vaginal wall or the surrounding pelvic muscle may sag with time. Childbirth also loosens the vaginal wall. In some women, the bladder may prolapse, meaning it is no longer supported and falls into the vagina. A prolapsed bladder is also known as cystocele or a fallen bladder. After urine leaves the bladder, it enters a single urethra, a tube-like structure that extends all the way to the genitals.
As you urinate, the bladder contracts and empties urine into the urethra. Then, the urethral sphincter muscle relaxes, and urination occurs. In women, the urethra is about 1. This is one reason women are more affected by urinary tract infections—the bacteria have a much shorter distance to travel. It can be hard to spot the urethra. Give It Up for the Kidneys.
The Three Steps of Urine Formation. Urine Storage and Elimination. Common Diseases and Disorders. When you select "Subscribe" you will start receiving our email newsletter. Use the links at the bottom of any email to manage the type of emails you receive or to unsubscribe. See our privacy policy for additional details. Learn Site. Kidneys Filter Blood at the Top of the Urinary System The kidneys are bean-shaped organs situated on the back of the abdominal wall, behind the peritoneum.
The Ureters Move Urine from the Kidneys to the Bladder Urine drains from the renal pelvis of each kidney into the ureters. The Female Urethra Is Shorter Than the Male Urethra Urine produced in the kidneys passes through the ureters, collects in the bladder, and is then excreted through the urethra.
External Sources A description of the organs of the urinary system from the edition of Gray's Anatomy of the Human Body. Get our awesome anatomy emails! About News Contact. All Rights Reserved.
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