The excretory organs of barnacles are maxillary glands. The animal lacks respiratory, excretory, and circulatory systems. Their excretory system consists of maxillary glands. Nettles have no excretory or respiratory organs. The abdomen also contains most of the digestive, respiratory, excretory and reproductive internal structures. The evisceration process is when the sexual, digestive and excretory organs are removed. Sea nettles have no excretory or respiratory organs. They are the digestive and excretory tracts. "Echinostoma" have a digestive system consisting of a pharynx, oesophagus and an excretory pore. The mammalian excretory system involves many components. The common ostrich is well adapted to hot, arid environments through specialization of excretory organs. Last is the necessity to release excretory products such as trophallactic secretions from the larvae. The role of "F. hepatica's" excretory system is excretion and osmoregulation. A one-way valve connects the pharynx to the excretory canal. Glomerular filtration rate falls and the kidney is unable to perform its normal excretory functions.