The urinary bladder is a temporary water-proof storehouse of urine. Its wall is thicker and lumen is much bigger than that of ureter. It is also comprised of inner mucous coat, middle muscular coat and outer fibrous coat.
The mucosa is thin and adherent to the underlying musculature in the region of trigon of urinary bladder. The epithelium is of the transitional variety and is made up of three to six layers in the empty bladder and of lesser number of layers in the distended bladder. It has the same characteristics as the transitional epithelium of the ureter. The lamina propria contains collagen and elastic fibers, capillaries and many nuclei of fibroblasts.
The muscular coat of urinary bladder known as detrusor muscle is made up of smooth muscle fibers running in all directions i.e. transverse, longitudinal and oblique with abundant interstitial connective tissue in between the bundles of muscle fibers. The circular layer is thickened at the internal urethral orifice to form the internal sphincter.
Only part of the bladder is covered with a mesothelial lining of peritoneum, the rest of it has an adventitial coat.
Adapted from: http://myaimst.net/mbbsb12/photo/histo/yr1histo/urinarybladder.html
Micro-photograph taken at AIMST University Anatomy Dissection Hall during Histology class, using Canon A40 camera over light microscope.