Editing Bladder (section)

== Histology ==

* '''Main histologic layers (3):'''
** '''Superficial to deep:'''
**# '''Urothelium'''
**#* '''Lacks bloods vessels or lymphatics, low opportunity for metastasis'''
**#* Normal bladder urothelium is multilayered and < 7 cells thick and rests on a thin basement membrane.
**# '''Lamina propria''' (suburothelial loose connective tissue)
**#* '''Rich blood vessels or lymphatics, high opportunity for metastasis'''
**#* '''Contains smooth muscle fibers collected into a poorly defined muscularis mucosae (different than muscularis propria)'''
**#** Muscularis mucosa is not present in 70% of specimens
**#** Invasion of muscularis mucosa is considered pT1
**# '''Detrusor or muscularis propria'''
**#* The relatively large muscle fibers form branching, interlacing bundles are loosely arranged '''into inner longitudinal, middle circular, and outer longitudinal layers'''
**#* Absent in diverticula