Urinogenital System of Uromastix (With Diagram) | Chordata | Zoology

In Uromastix, the excretory and reproductive systems are closely associated as in other vertebrates. Therefore, the two systems are described together under the heading urinogenital system. The sexes are separate but the sexual dimorphism is not well developed.

Excretory System:

The excretory system is similar in both the sexes and consists of a pair of kidneys, a pair of ureters and an unpaired urinary bladder.

Kidneys:

The kidneys are elongated, compact, dark-red bodies situated in the posterior portion of the body cavity, one on either side of and close to the median line. The kidneys are attached with the dorsal body wall outside the body cavity and are covered with peritoneum on their ventral surface only.

Kidneys are metanephric in nature. Each kidney is roughly divided into two lobes; the anterior broad and posterior narrow. The broad anterior lobes of both the kidneys are free and slightly apart, while the narrow posterior lobes are united so that they appear V-shaped.

Histology:

The kidneys are composed of narrow, much coiled uriniferous tubules, which are embedded in connective tissue having blood vessels, nerves and muscle fibres. These tubules communicate with their corresponding ureters.

Ureters:

From the ventral side of each kidney arises a narrow, short, delicate metanephric duct or ureter. Both the ureters open behind on the dorsal side into the middle chamber, the urodaeum, of the cloaca. Their openings into the urodaeum lie on small papillae.

Urinary Bladder:

The urinary bladder is a median thin-walled sac opening into the urodaeum of cloaca ventrally.

Physiology of Excretion: