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What is a Trigone?

Erica Stratton
Erica Stratton

The name trigone comes from the Latin word trigonum, meaning triangle. It is commonly used as a descriptor for parts of human anatomy that have a triangular shape, but is most commonly used for part of the urinary tract. It is also used to describe the space where three or four more plant cells meet.

In human anatomy, the word "trigone" is used to describe many things. It can refer to the shape of the cusps on some molars. The catoid trigone is a triangular area where many muscles meet at the base of the neck. The olfactory trigone is a triangular part of the brain connected with the sense of smell. Other types of trigones are spaces in the brain. Their enlargement or abnormality can be a sign of mental disease, such as dementia or schizophrenia.

An abnormality of trigones in the brain could be symptomatic of dementia or other cognitive disorder.
An abnormality of trigones in the brain could be symptomatic of dementia or other cognitive disorder.

Out of all of these, the area of the body most commonly referred to as trigone is located in the bladder. It is the area where two tubes from the kidneys, called ureters, meet with the urethra, which in turn leads to the bladder. This area is shaped like a triangle, hence the name, and is made entirely of smooth muscle.

This area is a very sensitive part of the anatomy. As the bladder fills, it stretches. This creates the sensation of "needing to go," which signals that it is time for the bladder to be emptied. One of the urinary sphincters, which either cuts off or allows urine to flow, is located nearby.

The olfactory trigone is connected with the sense of smell.
The olfactory trigone is connected with the sense of smell.

The sphincter located nearest to the trigone is involuntary, meaning it is not under conscious control. Another sphincter, located nearest to the genital opening, is the one that a person has conscious control over. If the trigone becomes overstretched, signaling that the bladder has become over-full, it will signal the involuntary sphincter to release the urine immediately.

Unlike other urinary tract infections, trigonitus may be further irritated by drinking cranberry juice.
Unlike other urinary tract infections, trigonitus may be further irritated by drinking cranberry juice.

Sometimes the trigone may become infected. This is called trigonitus. The walls of the trigone will take on a scaly appearance, making it extremely painful to urinate. Trigontius is different form a simple bladder infection in that it is much more difficult to treat, though it may have the exact same symptoms.

Trigonitis occurs more frequently in women than men, though the causes are unknown. Effective treatments are still being researched. A course of antibiotics may work for one person, but have no effect on another. Unlike usual urinary tract infections, trigonitus can be further irritated by drinking cranberry juice.

Discussion Comments

KoiwiGal

@Mor - I'm not sure that the two conditions are actually related. If your family is more likely to get urinary tract infections, it doesn't mean they will develop trigonitis. Researchers don't seem to know why anyone develops it.

In fact they don't know much about the condition at all and I don't think it is all that common. They don't have a reliable treatment for it yet either.

I think it is one of those names that is given to a condition which just happens sometimes, maybe because of another disease in the body, and at some point when they get a better grasp on it, they may even rename it or discover it is caused by more than one thing.

Mor

That's interesting and a little bit unnerving that trigontius is similar to a urinary tract infection but can be exacerbated by drinking cranberry juice. Because, several people in my family are very prone to getting urinary tract infections and my first instinct is always to make them drink lots of cranberry juice.

It really is usually the best thing they can do, and in fact since they are prone to the infections I try to get them to drink it all the time, and not just when they are already sick.

But, knowing that it can sometimes make the person worse makes it more complicated. I suppose we should just keep doing what has always worked in the past, however, and if necessary we can go to the doctor if the infection doesn't clear up.

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    • An abnormality of trigones in the brain could be symptomatic of dementia or other cognitive disorder.
      By: riccardo bruni
      An abnormality of trigones in the brain could be symptomatic of dementia or other cognitive disorder.
    • The olfactory trigone is connected with the sense of smell.
      By: snaptitude
      The olfactory trigone is connected with the sense of smell.
    • Unlike other urinary tract infections, trigonitus may be further irritated by drinking cranberry juice.
      By: Yingko
      Unlike other urinary tract infections, trigonitus may be further irritated by drinking cranberry juice.
    • The area of the body most commonly referred to as trigone is located in the bladder because the ureters meeting in the bladder form a triangle.
      By: rob3000
      The area of the body most commonly referred to as trigone is located in the bladder because the ureters meeting in the bladder form a triangle.
    • Trigontius is different from a simple bladder infection in that it is much more difficult to treat, though it may have the same symptoms.
      By: 7activestudio
      Trigontius is different from a simple bladder infection in that it is much more difficult to treat, though it may have the same symptoms.
    • An infected trigone may cause painful urination.
      By: arturas kerdokas
      An infected trigone may cause painful urination.
    • A urine test may be used to help diagnose trigonitis.
      By: Alexander Gospodinov
      A urine test may be used to help diagnose trigonitis.