If we have a section in a urinary bladder , we find it composed of layers.
1- Mucosa: the inner lining of transitional epithelium cells.
2- Submucosa: cosists of elastic fibers and mainly connective tissue, most of vessels are in this layer.
3- Muscular layer: detrusor muscle, It is a smooth muscle with not arranged fibers. It s mainly controls urine out from bladder.