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Urinary bladder
The bladder is lined by transitional epithelium. The underlying lamina is composed of a thinner, highly cellular portion adjacent to the epithelium and a thicker region of dense connective tissue closer to muscularis externa. The muscularis externa is composed of three ill-defined layers of smooth muscle (inner and outer longitudinal and middle circular layers). An adventitia is present beyond the muscularis externa. 100x
![Lumen <p>The bladder is lined by transitional epithelium. The underlying lamina is composed of a thinner, highly cellular portion adjacent to the epithelium and a thicker region of dense connective tissue closer to muscularis externa. The muscularis externa is composed of three ill-defined layers of smooth muscle (inner and outer longitudinal and middle circular layers). An adventitia is present beyond the muscularis externa. 100x</p>](https://digitalhistology.org/wp-content/uploads/2018/12/Or.Ur_.UB-3-2-ping.png)
Lumen
The bladder is lined by transitional epithelium. The underlying lamina is composed of a thinner, highly cellular portion adjacent to the epithelium and a thicker region of dense connective tissue closer to muscularis externa. The muscularis externa is composed of three ill-defined layers of smooth muscle (inner and outer longitudinal and middle circular layers). An adventitia is present beyond the muscularis externa. 100x
![Transitional epithelium <p>The bladder is lined by transitional epithelium. The underlying lamina is composed of a thinner, highly cellular portion adjacent to the epithelium and a thicker region of dense connective tissue closer to muscularis externa. The muscularis externa is composed of three ill-defined layers of smooth muscle (inner and outer longitudinal and middle circular layers). An adventitia is present beyond the muscularis externa. 100x</p>](https://digitalhistology.org/wp-content/uploads/2018/12/Or.Ur_.UB-3-1-ping.png)
Transitional epithelium
The bladder is lined by transitional epithelium. The underlying lamina is composed of a thinner, highly cellular portion adjacent to the epithelium and a thicker region of dense connective tissue closer to muscularis externa. The muscularis externa is composed of three ill-defined layers of smooth muscle (inner and outer longitudinal and middle circular layers). An adventitia is present beyond the muscularis externa. 100x
![Lamina propria <p>The bladder is lined by transitional epithelium. The underlying lamina is composed of a thinner, highly cellular portion adjacent to the epithelium and a thicker region of dense connective tissue closer to muscularis externa. The muscularis externa is composed of three ill-defined layers of smooth muscle (inner and outer longitudinal and middle circular layers). An adventitia is present beyond the muscularis externa. 100x</p>](https://digitalhistology.org/wp-content/uploads/2018/12/Or.Ur_.UB-3-3-ping.png)
Lamina propria
The bladder is lined by transitional epithelium. The underlying lamina is composed of a thinner, highly cellular portion adjacent to the epithelium and a thicker region of dense connective tissue closer to muscularis externa. The muscularis externa is composed of three ill-defined layers of smooth muscle (inner and outer longitudinal and middle circular layers). An adventitia is present beyond the muscularis externa. 100x
![Muscularis externa <p>The bladder is lined by transitional epithelium. The underlying lamina is composed of a thinner, highly cellular portion adjacent to the epithelium and a thicker region of dense connective tissue closer to muscularis externa. The muscularis externa is composed of three ill-defined layers of smooth muscle (inner and outer longitudinal and middle circular layers). An adventitia is present beyond the muscularis externa. 100x</p>](https://digitalhistology.org/wp-content/uploads/2018/12/Or.Ur_.UB-3-4-ping.png)
Muscularis externa
The bladder is lined by transitional epithelium. The underlying lamina is composed of a thinner, highly cellular portion adjacent to the epithelium and a thicker region of dense connective tissue closer to muscularis externa. The muscularis externa is composed of three ill-defined layers of smooth muscle (inner and outer longitudinal and middle circular layers). An adventitia is present beyond the muscularis externa. 100x
![Adventitia/serosa > <p>The fibrous adventitia contains adipose tissue, blood vessels and nerves. The superior and lateral portions of the bladder are covered by reflections of the peritoneum, forming a serosa, as present here. </p>](https://digitalhistology.org/wp-content/uploads/2018/12/Or.Ur_.UB-3-5-ping.png)
Adventitia/serosa >
The fibrous adventitia contains adipose tissue, blood vessels and nerves. The superior and lateral portions of the bladder are covered by reflections of the peritoneum, forming a serosa, as present here.