Definitions for salt gland
This page provides all possible meanings and translations of the word salt gland
a specialized gland, located near the eyes or nose of certain marine animals that secretes a liquid having a high salt content; it enables the animal to drink seawater without having to eliminate the excess salt through the kidneys
The salt gland is an organ for excreting excess salts. It is found in elasmobranchs, seabirds, and some reptiles. Sharks' glands are found in their rectum, birds' and reptiles' in or on the skull in the area of the eyes, nostrils or mouth. Salt glands maintain salt balance and allow marine vertebrates to drink seawater. Active transport via sodium-potassium pump action moves salt from the blood into the gland, where it is excreted as a concentrated solution. The aviary salt gland is coupled with a counter-current exchange mechanism that preserves high salt concentration in the blood plasma; most removed salt is returned to the incoming blood plasma, allowing the concentration buildup within the gland by active transport. The need for salt excretion in reptiles and birds reflects their having much less efficient kidneys than mammals. Unlike the skin of amphibians, that of reptiles and birds is impermeable to salt, preventing its release. The evolution of a salt gland in early reptiles and birds allowed them to eat aquatic plants and animals with high salt concentrations. This evolutionary development does not account for the gland in elasmobranchs, suggesting convergent evolution.
U.S. National Library of Medicine
A compound tubular gland, located around the eyes and nasal passages in marine animals and birds, the physiology of which figures in water-electrolyte balance. The Pekin duck serves as a common research animal in salt gland studies. A rectal gland or rectal salt gland in the dogfish shark is attached at the junction of the intestine and cloaca and aids the kidneys in removing excess salts from the blood. (Storer, Usinger, Stebbins & Nybakken: General Zoology, 6th ed, p658)
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