part_of starts_at ends_at bladder lamina propria of bladder anatomical_structure bladder mesenchymal layer EMAPA:30088 The lamina propria of bladder (lpbl) (TS:22-TS:28) is the thick mesenchymal cell layer of the bladder located between the urothelium and the detrusor muscle of bladder. Contains loose to dense (depending on region) connective tissue (marked by pro-collagen) many small blood vessels and nerves and thin, discontinuous wisps of smooth muscle (marked by smooth muscle markers; smooth muscle actin, desmin and actin). Contains nerve of lamina propria of bladder and is subdivided into suburothelial lamina propria of bladder (syn: suburothelial stroma of bladder, suburothelial mesenchyme of bladder, inner lamina propria of bladder) and outer lamina propria of bladder (syn: muscularis mesenchyme of bladder). These layers differ in their gene expression profile, presence of smooth muscle cells, vascularisation density and proliferation rates. During development the lamina propria of bladder is radially patterned into these two layers due to differentiation of the outer mesenchyme into smooth muscle. TS22 TS28