Trigone of the urinary bladder

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Trigone of urinary bladder
Illu bladder.jpg
Urinary bladder
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The interior of bladder.
Details
Identifiers
Latin trigonum vesicae urinariae
TA98 A08.3.01.024
TA2 3421
FMA 15910
Anatomical terminology

The trigone (also known as the vesical trigone) [1] is a smooth triangular region of the internal urinary bladder formed by the two ureteric orifices and the internal urethral meatus.

Contents

The area is very sensitive to expansion and once stretched to a certain degree, the urinary bladder signals the brain of its need to empty. The signals become stronger as the bladder continues to fill.

Embryologically, the trigone of the bladder is derived from the caudal end of mesonephric ducts, which is of mesodermal origin (the rest of the bladder is endodermal). In the female the mesonephric ducts regress, causing the trigone to be less prominent, but still present.

Pathology

Clinically important because infections (trigonitis) tend to persist in this region.

See also

Related Research Articles

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<span class="mw-page-title-main">Urinary system</span> Anatomical system consisting of the kidneys, ureters, urinary bladder, and the urethra

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<span class="mw-page-title-main">Ureter</span> Tubes used in the urinary system in most animals

The ureters are tubes composed of smooth muscle that transport urine from the kidneys to the urinary bladder. In an adult human, the ureters typically measure 20 to 30 centimeters in length and about 3 to 4 millimeters in diameter. They are lined with urothelial cells, a form of transitional epithelium, and feature an extra layer of smooth muscle in the lower third to aid in peristalsis. The ureters can be affected by a number of diseases, including urinary tract infections and kidney stone. Stenosis is when a ureter is narrowed, due to for example chronic inflammation. Congenital abnormalities that affect the ureters can include the development of two ureters on the same side or abnormally placed ureters. Additionally, reflux of urine from the bladder back up the ureters is a condition commonly seen in children.

<span class="mw-page-title-main">Seminal vesicles</span> Pair of simple tubular glands

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<span class="mw-page-title-main">Mesonephric duct</span> Paired organ in mammals

The mesonephric duct, also known as the Wolffian duct, archinephric duct, Leydig's duct or nephric duct, is a paired organ that develops in the early stages of embryonic development in humans and other mammals. It is an important structure that plays a critical role in the formation of male reproductive organs. The duct is named after Caspar Friedrich Wolff, a German physiologist and embryologist who first described it in 1759.

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<span class="mw-page-title-main">Inferior vesical artery</span>

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Trigone may refer to:

<span class="mw-page-title-main">Internal urethral orifice</span>

The internal urethral orifice is the opening of the urinary bladder into the urethra.

<span class="mw-page-title-main">Vesical venous plexus</span>

The vesical venous plexus is a venous plexus situated at the fundus of the urinary bladder. It collects venous blood from the urinary bladder in both sexes, from the accessory sex glands in males, and from the corpora cavernosa of clitoris in females. It drains into the internal iliac veins via several vesical veins.

Vesical arteries are variable in number. They supply the bladder and terminal ureter. The two most prominent are the superior vesical artery and the inferior vesical artery. The superior vesical artery comes off of the internal iliac artery and sometimes the umbilical artery. The inferior vesical artery comes off of the internal iliac artery. The inferior vesical artery is a pelvic branch of the internal iliac artery in men; and in women it branches from the vaginal artery. This literature has been reviewed recently with observations of variation in pelvic vascularization and the close relationship between vaginal and bladder vascularization in women.

Vesical refers to the urinary bladder and its relevant and nearby structures and functions, including:

<span class="mw-page-title-main">Vesical veins</span>

The vesical veins are veins in the pelvis that drain blood from the urinary bladder. The vesical veins receive blood from the vesical venous plexus and are tributaries of the internal iliac veins.

<span class="mw-page-title-main">Ectopic ureter</span> Congenital disorder of urinary system

Ectopic ureter is a medical condition where the ureter, rather than terminating at the urinary bladder, terminates at a different site. In males this site is usually the urethra, in females this is usually the urethra or vagina. It can be associated with renal dysplasia, frequent urinary tract infections, and urinary incontinence. Ectopic ureters are found in 1 of every 2000–4000 patients, and can be difficult to diagnose, but are most often seen on CT scans.

<span class="mw-page-title-main">Duplicated ureter</span>

Duplicated ureter or duplex collecting system is a congenital condition in which the ureteric bud, the embryological origin of the ureter, splits, resulting in two ureters draining a single kidney. It is the most common renal abnormality, occurring in approximately 1% of the population.

<span class="mw-page-title-main">Gartner's duct cyst</span> Medical condition

A Gartner's duct cyst is a benign vaginal cyst that originates from the Gartner's duct, which is a vestigial remnant of the mesonephric duct in females. Persistent Wolffian duct syndrome (PWDS) in individuals with XX chromosomes is the inverse disorder of Persistent Müllerian duct syndrome (PMDS) in individuals with XY chromosomes. They are typically small asymptomatic cysts that occur along the lateral walls of the vagina, following the course of the duct. They can present in adolescence with painful menstruation (dysmenorrhea) or difficulty inserting a tampon. They can also enlarge to substantial proportions and be mistaken for urethral diverticulum or cystocele. In some rare instances, they can be congenital.

References

  1. Woodburne, Russell T. (1965-03-01). "The Ureter, ureterovesical junction, and vesical trigone" (PDF). The Anatomical Record. 151 (3): 243–249. doi:10.1002/ar.1091510305. hdl: 2027.42/49801 . ISSN   1097-0185. PMID   14324081.