Editing Bladder (section)

===Microanatomy===
When [[Histology|viewed under a microscope]], the bladder can be seen to have an inner lining (called [[epithelium]]), three layers of muscle fibres, and an outer [[adventitia]].<ref name=Wheaters2013 >{{cite book |last1=Young |first1=Barbara |last2=O'Dowd |first2=Geraldine |last3=Woodford |first3=Phillip |title=Wheater's functional histology: a text and colour atlas.|publisher=Elsevier |location=Philadelphia |date=2013|isbn=9780702047473 |edition=6th|chapter=Urinary system|pages=315–7}}</ref>

The inner wall of the bladder is called [[urothelium]], a type of [[transitional epithelium]] formed by three to six layers of cells; the cells may become more cuboidal or flatter depending on whether the bladder is empty or full.<ref name=Wheaters2013 /> Additionally, these are lined with a [[mucous membrane]] consisting of a surface [[glycocalyx]] that protects the cells beneath it from urine.<ref name="Urothelium">{{cite journal |last1=Stromberga |first1=Z |last2=Chess-Williams |first2=R |last3=Moro |first3=C |title=Histamine modulation of urinary bladder urothelium, lamina propria and detrusor contractile activity via H1 and H2 receptors. |journal=Scientific Reports |date=7 March 2019 |volume=9 |issue=1 |pages=3899 |doi=10.1038/s41598-019-40384-1 |pmid=30846750|pmc=6405771 |bibcode=2019NatSR...9.3899S }}</ref> The epithelium lies on a thin [[basement membrane]], and a [[lamina propria]].<ref name=Wheaters2013 /> The mucosal lining also offers a urothelial barrier against the passing of infections.<ref name="Janssen">{{cite journal|last1= Janssen|first1= DA|title= The distribution and function of chondroitin sulfate and other sulfated glycosaminoglycans in the human bladder and their contribution to the protective bladder barrier.|journal= The Journal of Urology|date= January 2013|volume= 189|issue= 1|pages= 336–42|pmid= 23174248|doi=10.1016/j.juro.2012.09.022}}</ref>

These layers are surrounded by three layers of muscle fibres arranged as an inner layer of fibres orientated longitudinally, a middle layer of circular fibres, and an outermost layer of longitudinal fibres; these form the detrusor muscle, which can be seen with the naked eye.<ref name=Wheaters2013 />

The outside of the bladder is protected by a [[serous membrane]] called [[adventitia]].<ref name=Wheaters2013/><ref name=Fry2016rev>{{cite journal|last1= Fry|first1= CH|last2= Vahabi|first2= B|title= The Role of the Mucosa in Normal and Abnormal Bladder Function.|journal= Basic & Clinical Pharmacology & Toxicology|date= October 2016|volume= 119|issue= Suppl 3|pages= 57–62|doi= 10.1111/bcpt.12626|pmid= 27228303|pmc=5555362}}</ref>

<gallery>
File:Gray1141.png|Vertical section of bladder wall
File:Urinary bladder.JPG|Layers of the bladder wall and cross-section of the detrusor muscle
File:2605 The Bladder.jpg|Anatomy of the male bladder, showing transitional epithelium and part of the wall in a histological cut-out
</gallery>