What Are the Ureters?

The ureters are tube-shaped organs that deliver urine from the kidneys to the bladder.
Kidney stones can block a ureter.
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  • Written By: Lucinda Reynolds
  • Edited By: W. Everett
  • Last Modified Date: 24 September 2014
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The ureters are tube shaped organs whose main function is to deliver urine from the kidneys downward to the urinary bladder. They have a funnel shaped area at the top where they connect to the kidneys called the renal pelvis.

These tubes are approximately 9.8 inches (25 cm) long. These tubes descend downward into the pelvic cavity where they connect to the back of the bladder. There is a piece of mucus membrane that covers the opening through which urine enters the bladder. This acts as a one-way valve that allows urine into the bladder but prevents urine from leaking back up.

Three distinct layers make up the walls of each ureter. The inner layer contains epithelial cells that are the same types of cells that make up the lining of the bladder and parts of the kidneys. The middle layer consists of smooth muscle tissue and muscle fibers. The outer layer is made up of connective tissue.

Even though it may seem the ureters rely on gravity to move the urine down to the bladder, the middle layer of the lining actually produces waves to propel the urine along. This type of movement is called peristalsis, and the waves originate in the renal pelvis. If the kidneys are producing urine at a fast rate, peristaltic waves can occur every few seconds.


Once the peristaltic waves reach the bladder, a small jet of urine squirts into the organ. This may happen dozens of times before the bladder becomes full enough to signal the urge to urinate. The time it takes for the bladder to fill is dependent upon many factors, and an individual who drinks a lot of caffeine or alcohol, for example, can feel the urge to urinate frequently.

Because the linings of the ureters and the bladder are continuous, it is possible for infection to start in the bladder and ascend into the tubes. When this happens, they may become inflamed, a condition called ureteritis. Medical treatment is usually necessary to eliminate this inflammation.

Some individuals may develop kidney stones, which can block the movement of urine. If a stone is present, the section of the ureter above the stone will begin to produce strong peristaltic waves. These waves will try to push the stone into the bladder, where it can be eliminated. This is one reason why it can be extremely painful to pass a kidney stone. Surgical intervention is sometimes necessary to get rid of kidney stones.


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Post 7

@wavy58 – If you have frequent urinary tract infections, there is something you can drink that will promote the health of your ureters, bladder, and kidneys. Cranberry juice is nature's preventive measure and remedy for urinary tract infections.

I used to think that it only worked to prevent infections, but I have had success in treating mine with it. If I believe I have one, then I drink two glasses of cranberry juice a day until it goes away. I also take two cranberry extract pills, and they give my body an extra boost to fight the infection.

The cranberry juice is acidic, and it is able to keep the bacteria from clinging to the ureters or the bladder. The bacteria gets flushed out with your urine.

Post 6

@Monika – I got a kidney infection once that started out as a bladder infection. I could have avoided this, if I had sought treatment as soon as the symptoms of a urinary tract infection surfaced, but I had high hopes that it would go away on its own.

I kept the infection for about two weeks before I became very ill. What started out as frequent urination and lower abdominal cramps progressed to back pain and a fever. I woke up and vomited one morning, and then I knew that I had to do something.

My doctor gave me a strong antibiotic to treat the infection. He told me to always get help at the first sign of a urinary tract infection, because it would most definitely travel up my ureters if given the chance.

Post 5

I have never personally experienced a kidney stone, but I have a friend who has had to have surgery on many occasions to remove them. Hers have been large enough to block her ureters, and the doctor had to bust them up with a laser so that she could pass them.

She said that the pain was so bad at first that she could not get up off the floor. Her husband had to carry her to the car to take her to the hospital, where they gave her pain medicine as soon as she got into a room.

Once the stones had been broken into small pieces, they could exit her body through her ureters. I don't know why some people suffer from these and some don't, but she seems especially prone to them. At least there is a way to break them up that doesn't involve cutting into the ureters.

Post 4

I always imagined urine slowly trickling into the bladder. I never knew that it squirted in there through the ureters in short bursts.

I feel the need to urinate fairly often, so my ureters stay pretty busy throughout the day. I have to go about once an hour, and that's when I'm not drinking very much at all.

I used to have to urinate even more frequently, but since I've stopped drinking caffeinated sodas, the urge has eased up some. I know my ureters probably appreciate the break!

Post 3

It makes a lot of sense that the ureters have a one way valve, as do a lot of other things in the body (veins, the heart). After all, the whole purpose of the ureters is to move waste from the kidney to the bladder where it can be expelled from the body.

If the valve was a two way valve, the waste could flow back through the ureters to the kidney. I imagine this would disrupt the whole urinary tract and probably result in a bad health outcome for the person.

Post 2

@Monika - A urinary tract infection can definitely travel into the ureters. How else do you think a urinary tract infection becomes a kidney infection? The bacteria aren't just magically transported to the kidneys, they travel there through the ureters.

Anyway, I'm not surprised that the ureters are made up of a layer of smooth muscle. When I took Anatomy and Physiology, I remember learning that most of our organs have smooth muscle fibers.

Smooth muscles are responsible for involuntary movements, which are essential for keeping the body going. Imagine if you had to consciously think about moving waste through your ureters to your bladder?

Post 1

I had no idea that a urinary tract infection could actually travel upwards into the ureters. I used to get recurring urinary tract infections, but luckily they never migrated to anywhere else in my body.

Still, the idea is scary. I imagine an infection that extends past the bladder is probably harder to get rid of than your average, annoying urinary tract infection.

It makes sense though, especially since the whole system is connected and made up of the same kinds of tissues. If an infection could affect the bladder, there's no reason it couldn't affect the ureters too.

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