Deiodinase
Definition:
The enzyme found in target tissues of the thyroid hormones that converts thyroxine (also known as tetraiodothyronine or T
4) to triiodothyronine (T
3).
Specifically, 5'-deiodinase converts T
4 to the active form of the thyroid hormone, T
3.
5-Deiodinase converts T
4 to the inactive form of the thyroid hormone, reverse T
3 (rT
3).
Duodenum
Definition:
The first region (i.e., most proximal region) of the small intestine.
Chyme leaving the stomach (through the pyloric valve) first enters the duodenum. The contents of the duodenum empty into the
jejunum (middle region of the small intestine). In adult humans, the duodenum is about 25-38 cm (10-15 inches) long.
Related glossary terms/phrases:
JejunumIleum
Dyspareunia
Definition:
Difficult or painful intercourse.
Posted: Saturday, March 2, 2013
Last updated: Wednesday, March 12, 2025