Kemppainen, Robert J. Department of Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, Alabama.
Last reviewed:March 2021
- Adrenal cortex and adrenal medulla
- Comparative anatomy
- Cyclostomes (hagfish and lamprey)
- Elasmobranchs (sharks and rays)
- Teleosts (bony fish)
- Comparative endocrinology
- Chromaffin cells
- Steroid hormones
- Related Primary Literature
- Additional Reading
A complex endocrine organ in proximity to the kidney. The adrenal gland (see illustration), often called simply as the adrenal, is an important endocrine organ located on top of the kidneys. Adrenal gland tissue is present in all vertebrates from cyclostomes to placental mammals. In particular, adrenal glands occur as paired organs in mammals, most birds, and most reptiles. Structurally, the adrenal consists of two functionally distinct tissues: steroidogenic cells of mesodermal origin and neural crest–derived catecholamine-secreting cells. Whereas "adrenal" refers to the gland's proximity to the kidney, significant variation exists among vertebrates in its anatomic location and the relationship of the two endocrine tissues that make up the gland. In mammals, steroidogenic cells are separated into distinct zones that together form a cortex. This cortical tissue surrounds the catecholamine-secreting cells, constituting the medulla. In most other vertebrates, this unique anatomic cortical-medullary relationship is not present. In species of amphibians and fish, adrenal cells are found intermingling with kidney tissue, and the steroidogenic cells are often termed interrenal tissue. Malfunctions of the paired adrenal glands are most often characterized by abnormal hormone secretion. See also: Adrenal gland disorders; Endocrine mechanisms; Endocrine system (vertebrate); Endocrinology; Gland; Hormone; Kidney
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 46 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