The Urinary Bladder

THE URINARY BLADDER
ANATOMY
Gross Appearance
The bladder is a hollow muscular organ that serves as a reservoir for urine. The adult bladder normally has a capacity of 400–500 mL.
ANATOMY
When empty, the adult bladder lies behind the pubic symphysis and is largely a pelvic organ. In infants and children, it is situated higher.
When it is full, it rises well above the symphysis and can readily be palpated or percussed.
When overdistended, as in acute or chronic urinary retention, it may cause the lower abdomen to bulge visibly. Extending from the dome of the bladder to the umbilicus is a fibrous cord, the median umbilical ligament, which represents the obliterated urachus.
The ureters enter the bladder posteroinferiorly in an oblique manner and at these points are about 5 cm apart. The orifices, situated at the extremities of the crescent-shaped interureteric ridge that forms the proximal border of the trigone, are about 2.5 cm apart. The trigone occupies the area between the ridge and the bladder neck.
The internal surface of the bladder is lined with transitional epithelium.
Deep to this, the lamina propria forms a relatively thick layer of fibroelastic connective tissue that allows considerable distention. Beneath this layer lies the smooth muscle of the bladder wall which called detrusor muscle layer this meshwork of detrusor muscle is ideally suited for
emptying the spherical bladder..