THYROID GLAND & METABOLISM Flashcards
Lipophilic hormones are primarily produced by the:______
Gallbladder
Liver
Pancreas
Kidney
Liver
HPT axis stands for
Hypothalamus anterior pituitary thyroid axis
(Pathway for thyroid hormones)
In HPT axis the hypothalamus releases :_____ hormone
Thyrotropin releasing hormone (TRH)
In HPT axis the anterior pituitary releases ____ hormone
Thyroid stimulating hormone (TSH)
C cells of thyroid gland release :
Adrenaline
Calcitonin
TSH
TRH
Calcitonin
Follicular cells of thyroid gland secrete _____ hormone.
Calcitonin
Glycoprotein
Neurotransmitter
Thyroid hormone
Follicular hormone
Thyroid hormone
Colloid of thyroid gland is a _____
Receptor
Hormone
Ion channel
Glycoprotein
Glycoprotein
Thyroid hormone is 2 hormones: T3(___) and T4(___)
Membrane of the ____ hormone class
Triiodothyronine and tetraiodothyronine
Tyrosine
Tyrosine synthesized in body but _____ must be obtained from the diet, which is a halogen
Iodine
Order synthesis of thyroid hormones steps:
A. Iodine is co-transported into cell with Na+ and transported into colloid couple = T3 & T4
B. Follicular cell synthesizes enzymes and thyroglobulin for colloid
C. Thyroid peroxidase oxidizes iodide ions, MIT/DIT’s
D. Intracellular enzymes separate T3&T4 from protein
E. Thyroglobulin taken back into cell
B, a, c, e, d
Is T3 or T4 the principle thyroid hormone ?
T3
Every step of thyroid hormone synthesis and secretion is controlled by this hormone from the anterior pituitary
TSH
TSH production is controlled by this hormone from the hypothalamus
TRH Thyrotropin releasing hormone
This hormone maintain structural integrity of the thyroid gland
-deficiency causes atrophy of gland
- excess TSH produces y per trophy and hyperplasia of follicular cells
- enlarged thyroid called a goiter
TSH
An enlarged thyroid is called a ____
Goiter
_____= an estimate of an individuals basal energy expenditure required to maintain vital function; usually measured after a 12 hour fast in a resting state
BMR
BMR stands for ____
Basal metabolic rate
Thyroid hormones have differential effects on intermediate metabolism depending on level of production: which one is catabolic and anabolic ?
-for normal adults the net effect is _____
- pathologically high amounts cause futile cycles of metabolism ; the net effect is______
Anabolic
catabolic
Are thyroid hormones permissive or restrictive for GH activity ?
Permissive
Low secretion of thyroid hormones = _____
Hypothyroidism
Excess secretion of thyroid hormones =___
Hyperthyroidism
