Kidney always so simple; in cartilaginous fish and some amphibians, there is also a shorter duct, similar to the amniote ureter, which drains the posterior (metanephric) parts of the kidney, and joins with the archinephric duct at the bladder or cloaca. Indeed, in many cartilaginous fish, the anterior portion of the kidney may degenerate or cease to function altogether in the adult. In the most primitive vertebrates, the hagfish and lampreys, the kidney is unusually simple: it consists of a row of nephrons, each emptying directly into the archinephric duct. Invertebrates may possess excretory organs that are sometimes referred to as
Urinary bladder disease Urinary bladder disease Urinary bladder disease includes urinary bladder inflammation such as cystitis, bladder rupture and bladder obstruction (tamponade). Cystitis is common, sometimes referred to as urinary tract infection (UTI) caused by bacteria, bladder rupture occurs when the bladder is overfilled and not emptied while bladder tamponade is a result of blood clot formation near the bladder outlet. Cystitis is a urinary bladder inflammation that results from any one of a number of distinct syndromes. It is most commonly caused by a bacterial infection in which case it is referred to as a urinary tract infection. Bladder rupture (rupture of