Urinary Bladder
From Knoesis wiki
Organ with organ cavity which is continuous proximally with the right and left ureters and distally with the urethra. Examples: There is only one urinary bladder. // Four processes (canals) of the excretory canal cell each contain a central collecting lumen which feeds to a central lumenal canal in the cell body; the central canal forms a specialized membrane to release fluids into the excretory duct. These five canals form a continuous H-shaped channel which extends almost the full length of the body, generally in contact with the lateral hypodermis and the pseudocoelom.