T

T3
An abbreviation for triiodothyronine, one of the thyroid hormones.
T4
An abbreviation for thyroxine, one of the thyroid hormones.
target cell
A cell which is responsive to a particular hormone because it bears the receptor for that hormone.
taste
A "special sense" involving detection of chemical stimuli by taste buds in the oral cavity.
teeth
Specialized bone-like structures in the jaw used for biting and chewing.
terminal transferase
An enzyme that catalyzes the addition of nucleotides to the 3-prime termini of DNA.
thyroglobulin
A large, dimeric protein synthesized by thyroid epithelial cells. Serves as a precursor for synthesis of thyroid hormones.
thyroid gland
An endocrine organ located in the neck that secretes thyroid hormones and calcitonin.
thyroid-releasing hormone
A small peptide hormone secreted by the hypothalamus that stimulates secretion of thyroid-stimulating hormone from the anterior pituitary.
thyroid-stimulating hormone
A glycoprotein hormone secreted from the anterior pituitary that stimulates secretion of thyroid hormones.
thyrotoxicosis
A form of hyperthyroidism or excess of thyroid hormones.
thyrotropin
Another name for thyroid stimulating hormone.
thyroxine
A hormone produced by the thyroid gland. Also called 3,5,3',5'-tetraiodothyronine.
trancellular
Passage through cells. Many nutrients are transported across the intestine by transcellular passage. In contrast to paracellular.
trans-
Prefix meaning through, across or beyond.
transcription factor
A term used to describe any protein that participates in initiating transcription. Transcription factors bind either to DNA or to other proteins that bind DNA.
translocation
A chromosomal abnormality which occurs when chromosomes break and the fragments rejoin to other chromosomes.
triglyceride
A type of lipid also called neutral fat. A prominent fat in diets.
triiodothyronine
A hormone produced by the thyroid gland.
trypsin
A proteolytic enzyme that digests proteins into peptides. Produced in abundance by the pancreas.
Turner's syndrome
X chromosome monosomy; a chromosomal disease due to having a single X sex chromosome.

Last updated on 10/2/2004