Term
| synthesis of thyroid hormone |
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Definition
1.synthesized from glycoprotein thryoglobulin
2.in colloid, iodine atoms are added to tyrosine in the thyroglobulin peptide chain
3.iodinated thyroglobulin is further processed to form mature thyroglobulin which is stored as colloid in the follicles
4.release of thyroid hormone-the mature thyroglobulin is endocytized by the follicular cells and lysosomal enzymes carry out hormone, allowing it to diffuse in the bloodstream |
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Term
| Release of thyroid hormone |
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Definition
1.Thyroglobulin is endocytized by follicular cells
2.Lysosomal proteases carve out T3 and T4
3.T3 and T4 in ratio 1:10 are transported in the blood by specific transport proteins
4.T3 and T4 enter target cells
5.T3 and T4 bind to intracellular receptor proteins; these receptor proteins interact with transcriptional enhancer elements found in nuclear DNA which increase transcription rate of DNA to mRNA and enhance gene expression |
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Term
| Negative feedback controls on TSH secretion |
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Definition
| levels of T3 and T4 in the blood control TSH production so if it is low, TSH secretion by anterior pituitary increases. Vice Versa, block action of TRH on thyrotroph cells of anterior pituitary which inhibit secretion of more TSH |
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Term
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Definition
Caused by hyperthyroidism. Body produces antibodies and mimics effects of real TSH.
Symptoms: weight loss, wide eyed stare, rapid heart rate, tremors, loss of muscle mass
Treated= surgery by removal of parathyroid gland and drugs that block thyroid hormone synthesis |
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Term
| Hypothyroidism symptoms/treatment |
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Definition
cretinism: marked retardation of growth, slowing of ossification, and failure of CNS to develop.
large gain in weight, slow heart beat, slow movement in speech and thought
Treatment: thyroid hormone pills and iodine |
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Term
| 3 causes of hypothyroidism |
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Definition
iodine deficiency: T3 and T4 cant be synthesized so tissue of gland stimulated to grow by persistent levels of high TSH secreted by anterior pituitary which will cause GOITER
Hashimoto thyroiditis: autoimmune destruction
Atrophy: gland does not fully develop. Unable to execute all of its functions |
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Term
Game: Levels of TSH and T4 high or low?
Graves Disease |
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Definition
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Term
| Hashimoto's thyroiditis (follicle cell degeneration) |
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Definition
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Term
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Definition
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Term
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Definition
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Term
| loss of hypothalamic TRH secreting cells |
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Definition
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