Arey, Leslie B. Department of Cell Biology and Anatomy, Northwestern University Medical School, Chicago, Illinois.
- Related Primary Literature
- Additional Reading
Glands located in the mouth that secrete fluids that moisten and lubricate the mouth and food, often initiating digestive activity or performing other specialized functions. Fishes and aquatic amphibians have only solitary mucus (slime)–secreting cells, which are distributed in the epithelium of the mouth cavity. Multicellular oral glands first appeared in land animals to keep the mouth moist and make food easier to swallow. These glands occur in definite regions and have been assigned distinctive names. Some glands of terrestrial amphibians have a lubricative secretion; others serve to make the tongue sticky for use in catching insects. Some frogs secrete a watery serous fluid that contains ptyalin, a digestive enzyme. The oral glands of reptiles are much the same, but are more distinctly grouped. In poisonous snakes and the single poisonous lizard, the Gila monster, certain oral glands of the serous type are modified to produce venom. Also, many of the lizards have glands that are mixed in character, containing both mucous and serous cells. Oral glands are poorly developed in crocodilians and sea turtles. Birds bolt their food in gulps and swallow without chewing; however, grain-eating birds have numerous glands, with some of these glands secreting ptyalin. See also: Digestive system; Enzyme; Gland; Mouth; Poison gland
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Contributors include more than 10,000 highly qualified scientists and 45 Nobel Prize winners.
MORE THAN 8700 articles covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 19,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information