Urinary Bladder

Urinary Bladder/Function of urinary bladder

The urinary bladder is reservoir for the urine. 

Urinary Bladder is hollow muscular organ that collects urine from ureters and store it.

It is temporary store house of urine which gets emptied through the urethra. It expel urine into urethra.

Bladder varies in it's size, shape and location according to amount of urine it contains.

Bladder is located on the floor of pelvic cavity. It usually accumulates 200 to 400ml of urine before emptying.

Organ which are associated with urinary bladder

Anteriorly; On the anterior side is symphysis pubis. 

Posteriorly; Uterus and upper part of vagina

Superiorly; Small intestine

Interiorly; Urethra and muscle forming pelvic floor

Organ associated with urinary bladder in male

Anteriorly; Symphysis pubic

Posteriorly; rectum and seminal vesicle

Superiorly; small intestine

Inferiorly; urethra and prostate gland

Structure of urinary bladder

The bladder is roughly pear shaped and becomes round when fill with urine.

Bladder open into urethra.

Parts of urinary bladder

Urinary Bladder has an apex, base and neck.

Bladder neck is lowest and fixed part of bladder.

Layers of Urinary Bladder

1. Tunica mucosa

2. Tunica muscularis

3. Adventitia or tunica serosa 

1. Tunica mucosa ( inner layer)

Lined with transitional epithelium

Allow bladder to stretch and contract

When bladder empty, tunica mucosa thrown into folds called rugae.

2. Tunica muscularis (thick middle layer)

Mass contraction and peristalsis.

Inner and outer longitudinal smooth muscle fibers.

Middle; Circular smooth muscle fibers.

3. Adventitia (out layer of bladder)

Derived from peritoneum and covers only upper and lateral surfaces of bladder.

It moist tissue and lubrication.

Elimination friction