What Is the Urinary Bladder?

It is a muscular cystic organ that stores urine. Its shape, size, location, and wall thickness vary with the degree of urine filling. The average bladder volume of an adult is 350-500 ml. When it exceeds 500 ml, pain occurs due to excessive tension of the bladder wall. The maximum capacity of the bladder is 800 ml. The volume of the bladder in newborns is about one-tenth that of adults. The capacity of women is smaller than that of men. The elderly have increased capacity due to low tension of the bladder muscles.

It is a muscular cystic organ that stores urine. Its shape, size, location, and wall thickness vary with the degree of urine filling. The average bladder volume of an adult is 350-500 ml. When it exceeds 500 ml, pain occurs due to excessive tension of the bladder wall. The maximum capacity of the bladder is 800 ml. The volume of the bladder in newborns is about one-tenth that of adults. The capacity of women is smaller than that of men. The elderly have increased capacity due to low tension of the bladder muscles.

Chinese name

bladder

Foreign name

Bladder

Category

Urine storage organ

Sound

pang guang

Location

Anterior pelvic anterior rectum

Bladder morphology

The empty bladder has a triangular vertebral body shape, divided into four parts: tip, body, sole and neck. The tip of the bladder is facing forward and upward, so there is a fold between the anterior wall of the abdomen and the umbilicus as the umbilical median ligament. The bladder body is between the tip of the bladder and the bottom of the bladder. The lowest part of the bladder is the neck of the bladder, which is adjacent to the prostate of men and the pelvis of women.

Bladder anatomy

The inner surface of the bladder is covered with mucous membranes. When the bladder wall contracts, the mucous membranes gather into folds called bladder loops. On the inside of the bottom of the bladder, there is a triangular area between the left and right ureteral openings and the inner urethral opening. Here the bladder mucosa is tightly connected to the muscular layer and lacks submucosal tissue. It remains smooth regardless of whether the bladder expands or contracts. Called the bladder triangle. The triangle of the bladder is a common site for tumors, tuberculosis, and inflammation. Special attention should be paid to cystoscopy. The fold between the two ureteral orifices is called the ureteral diaphragm. A pale band seen under cystoscopy is a sign of clinically looking for a ureteral orifice. In the triangle of the bladder behind the male urethral orifice, a longitudinal ridge-like bulge formed by the middle lobe of the prostate is called a bladder ptosis.

Bladder is a disease of the bladder

1. Cystitis

Cystitis is a common urinary tract infection, accounting for more than 60% of urinary tract infections. It is divided into acute simple cystitis and recurrent cystitis. Most of the pathogenic bacteria are E. coli, which accounts for more than 75%, and they usually occur in women, because women's urethra is shorter than men's urethra, close to the anus, and E. coli is easy to invade. The main clinical manifestations of cystitis are frequent urination, urgency, dysuria, dysuria, lower abdominal pain, end-hematuria is common, and some patients quickly have difficulty urinating.

2. Bladder tuberculosis

Bladder tuberculosis is secondary to renal tuberculosis, and a small number is caused by prostate tuberculosis. Bladder tuberculosis and urogenital tuberculosis often coexist. Early lesions are inflammation, edema, congestion, and ulcers, and bladder contracture occurs in the later stages. Lesions involve stenosis or insufficiency of the ureter, resulting in hydronephrosis of the kidneys and ureters, and impaired renal function. Bladder tuberculosis often evolves from renal tuberculosis. The initial symptoms of most patients with tuberculous cystitis are frequent urination, and urinary frequency gradually increases with urgency, dysuria, and hematuria. Urination gradually increases from 3 to 5 times per day to 10 to 20 times per day. If the bladder symptoms worsen, the mucous membrane has extensive ulcers or bladder contractures, and the capacity decreases, the urination reaches dozens of times a day, and even the patient suffers incontinence.

Bladder cancer

Bladder cancer is a malignant tumor that develops on the mucosa of the bladder. It is the most common malignant tumor of the urinary system and one of the ten most common tumors in the body. In 2012, the incidence of bladder cancer in the national tumor registration areas was 6.61 per 100,000, ranking 9th in the incidence of malignant tumors. Bladder cancer can occur at any age, even in children. Its incidence increases with age, with a high incidence of 50 to 70 years. The incidence of bladder cancer in men is three to four times that of women. The bladder mucosal epithelium was previously referred to as transitional cells. In 1998, the WHO and the International Society of Urology recommended that the term urothelial be used instead of the term transitional cell to distinguish it from the transitional epithelium in the nasal cavity and ovaries, making the urothelial urine A proper term for road systems. The pathological types of bladder cancer in the histological classification of urinary tract tumors in the "Urology and Genetics of Tumors of the Urinary System and Male Reproductive Organs" by WHO in 2004 include bladder urothelial carcinoma, bladder squamous cell carcinoma, bladder adenocarcinoma, other rare There are also bladder clear cell carcinoma, bladder small cell carcinoma, and bladder carcinoid. Among them, the most common is bladder urothelial cancer, which accounts for more than 90% of the total number of bladder cancer patients. The bladder cancer is generally referred to as bladder urothelial cancer, which was previously called bladder transitional cell carcinoma.