Snake Urinary System

Kidneys of a Burmese python ©RVC and its licensors, Peer Zwart and Fredric Frye. All rights reserved

The urinary system of snakes consists of paired lobulated kidneys and ureters that empty into the dorsal urodeum.

Kidney

Paired kidneys are located in the dorsal caudal coelomic cavity with the right kidney cranial to the left. They are elongated, lobulated and somewhat triangular in cross section. All reptiles have metanephric kidneys that are simpler than the mammalian counterpart. There are decreased number of glomeruli (some species are aglomerular) and there is no loop of Henle. They may have one or more renal arteries, and in some species, there is a separate branch of the ureter draining each lobule. There may be a sexual segment in the caudal kidney that follows up the distal part of each tubule and empties into a collecting duct. Since no urinary bladder is present, urine is not stored and ureters empty directy into the cloaca.

Uric acid

Uric acid is the main form of nitrogenous waste with lesser amounts of ammonia and urea depending on the species, the natural environment and degree of water conservation required. Uric acid is excreted by tubular secretion rather than urea by glomerular filtration

Ureters and Cloaca

Snakes have no bladder. The ureter enters the urodeum at a urogenital papilla and urine refluxes into the colon for fluid conservation.

• Read the definition of cloaca.
• For more information on excretion in reptiles, see here.

Reference

Mader, D.R. (2005). Reptile Medicine and Surgery. Saunders. pp. 49. ISBN 072169327X