The trigone (a.k.a. vesical trigone) is a smooth triangular region of the internal urinary bladder formed by the two ureteric orifices and the internal urethral orifice. 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.
In all other regions, the outer layer is fibrous connective tissue. There is a triangular area, called the trigone, formed by three openings in the floor of the urinary bladder. Two of the openings are from the ureters and form the base of the trigone.
Furthermore, what is the dome of the bladder? It is separated from the pubic symphysis by an anterior prevesical space known as the space of Retzius or retropubic space. The dome of the bladder is covered by peritoneum, and the bladder neck is fixed to neighboring structures by reflections of the pelvic fascia and by true ligaments of the pelvis.
Then, how does the Trigone differ from the rest of the bladder?
Trigone: Trigone is the triangular area of mucous membrane covering the internal surface of the base of the bladder between the two ureteral orifices superiorly and the urethral orifice inferiorly. Unlike the rest of the bladder, the mucous membrane of trigone is always devoid of folds, even when the bladder is empty.
What are the anatomical boundaries of the trigone of the bladder?
The trigone of the bladder is a smooth trangular region at the base of the bladder. Its borders are the openings of the two ureters and the urethra.
What does Trigonitis mean?
Trigonitis is a condition of inflammation of the trigone region of the bladder. It is more common in women. The cause of trigonitis is not known, and there is no solid treatment.
What is the primary function of the bladder?
When empty, the bladder is about the size and shape of a pear. Urine is made in the kidneys and travels down two tubes called ureters to the bladder. The bladder stores urine, allowing urination to be infrequent and controlled. The bladder is lined by layers of muscle tissue that stretch to hold urine.
What are common bladder problems?
Summary Cystitis – inflammation of the bladder, often from an infection. Urinary incontinence – loss of bladder control. Overactive bladder – a condition in which the bladder squeezes urine out at the wrong time. Interstitial cystitis – a chronic problem that causes bladder pain and frequent, urgent urination.
Why is Trigone medically important?
Precise connections between ureters and the trigone are crucial for function of the valve mechanism that prevents back flow of urine from the bladder to the ureters, a major cause of reflux and obstruction, which can damage the kidney and cause severe health problems including end-stage renal disease.
How much urine can the bladder hold?
A healthy bladder can hold one and a half to two cups (300-400mls) of urine during the day and about four cups (800mls) at night. It is normal to pass urine five or six times a day if you drink between 6-8 glasses of fluid.
Why is the trigone of the urinary bladder clinically important?
Why is the trigone of the urinary bladder clinically important? Both sperm and urine pass through the trigone in males. The trigone is longer in males than in females.
What are the symptoms of Trigonitis?
Symptoms of trigonitis an urgent need to urinate. pelvic pain or pressure. difficulty urinating. pain during urination. blood in the urine.
What is the opening of the bladder called?
The three openings, two ureteric orifices, and the internal urethral orifice mark the triangular area called the trigone of the bladder. These openings have mucosal flaps in front of them that act as valves in preventing the backflow of urine into the ureters, known as vesicoureteral reflux.
How long is the urethra to the bladder?
The urethra provides an exit for urine as well as semen during ejaculation. This is the intramural part of the urethra and varies between 0.5 and 1.5 cm in length depending on the fullness of the bladder.
How many ureters do we have?
What is the opening between the bladder and urethra?
The bladder neck is a funnel-shaped extension at the bottom of the bladder that then connects with the urethra. It is 2–3 cm long and forms a muscular band around the urethra, known as the internal sphincter. This sphincter is normally closed tight to stop urine from leaking out of the bladder.
What structures make up the Trigone?
The trigone is the triangular area made up of the openings from the ureters and the opening into the urethra. The urethra is the tube from the bladder to the outside of the body.
What type of connective tissue is found in the urinary bladder?
The urothelium is the inner lining of the bladder. It is made up of urothelial cells (also called transitional cells). The urothelium is also called the transitional epithelium. The lamina propria (also called the submucosa) is a thin layer of connective tissue that surrounds the urothelium.
What triggers the urinary reflex?
When the bladder is full of urine, stretch receptors in the bladder wall trigger the micturition reflex. The detrusor muscle that surrounds the bladder contracts. The internal urethral sphincter relaxes, allowing for urine to pass out of the bladder into the urethra. The external urethral sphincter is voluntary.