Thyroid Hormone Flashcards
The material in the center of a thyroid follicle surrounded by follicular epithelial cells is called .
Colloid
The increased oxygen consumption that stems from thyroid hormone release causes a(n) (increase/decrease) in cardiac output.
INCREASE
The freshly synthesized thyroid hormones in colloid are attached to .
Thyroglobulin
Tetraiodothyronine is converted to triiodothyronine by the enzyme by removing one atom from I2.
5-deiodinase
Tetraiodothyronine is formed by the combination of two molecules.
Diiodotyrosine molecule
The form of thyroid hormone that is more active is (triiodothyronine/tetraiodothyronine) .
Triiodothyronine (T3)
Thyroglobulin contains a large amount of (amino acid) .
TYROSINE
The second messenger for thyroid stimulating hormone is .
cAMP
The transports iodine from blood into follicular epithelial cells.
Na I symporter
Triiodothyronine binds to a receptor, and then stimulates DNA transcription by binding to a thyroid-regulatory element.
Nuclear
The effect occurs when large amounts I- inhibit organification, which is the combination of I2 and tyrosine of thyroglobulin to form monoiodotyrosine and diiodotyrosine.
Wolff-Chaikoff effect
Thyroid hormone circulates the bloodstream bound to .
THYROXINE BINDING GLOBULIN
The thyroid gland synthesizes thyroid hormone in its epithelial cells.
Follicular
Decreased thyroxine-binding globulin, such as in hepatic failure, results in (increased/decreased) levels of free thyroid hormones and decreased synthesis of thyroid hormones.
Increased
Thyroid gland growth is regulated by hormone
TSH
Thiocyanate and perchlorate are (competitive/noncompetitive) inhibitors of Na+-I- cotransport.
COMPETITIVE
Increased basal metabolic rate, weight loss, sweating, and increased heat production are all symptoms of (hyperthyroidism/hypothyroidism) .
HYPERTHYROIDISM
The formation of (triiodothyronine/tetraiodothyronine) is much faster than the other.
Tetraidothyronine
A dietary I- deficiency appears similar to a deficiency of (enzyme) .
Thyroid deiodinase
The hepatic breakdown of thyroxine-binding globulin is inhibited during pregnancy due to high levels of , causing an increased synthesis of thyroid hormones by removing negative feedback.
Estrogen
is formed by the combination of one monoiodotyrosine and one diiodotyrosine molecule.
Triiodothyronine
The Na+-I- cotransport pump increases activity when the body has too (much/little) iodine.
little
The T3 resin uptake test assesses the circulating levels of .
Thyroxine binding globulin
is released from the hypothalamus to stimulate secretion of thyroid stimulating hormone from the anterior pituitary.
THYROTROPIN RELEASING HORMONE
Heart rate and contractility increase when thyroid hormone is released due to its effect on their receptors.
Beta 1 adrenergic receptors
Iodine ions are oxidized to I2 by (enzyme) when they reach the apical membrane of the cell.
Thyroid Peroxidase (TPO)
Thyroid hormone (increases/decreases) basal metabolic rate and body temperature through increased oxygen consumption.
INCREASES
The nuclei of the hypothalamus release oxytocin
Paraventricular
The thyroid gland secretes 90% of its thyroid hormone in the form of (triiodothyronine/tetraiodothyronine)
tetraiodothyronine
