Term
| What is colloid predominantly made up of? |
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Definition
| Thyroglobulin, which is synthesized and secreted by the follicular cells |
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Term
| What is the Iodide dietary average intake? |
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Definition
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Term
| The very large pool of iodide stored in the thyroid ensures against iodide deficiency for how long? |
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Definition
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Term
| What is the Wolff-Chaikoff effect? |
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Definition
| If iodide intake exceeds 2 mg/day, the excess iodide in the thyroid gland inhibits the iodide trap and hormone synthesis |
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Term
| Describe what is meant by iodide trap? |
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Definition
| The coupling of the transported iodide to thyroglobulin in the lumen of the thyroid gland traps the iodide within the gland |
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Term
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Definition
| Pendrin is an anion exchanger which transports the iodide from the thyroid follicular cell to the lumen of the follicle |
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Term
| Hyperthyroidism is diagnosed base on the measurement of what? |
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Definition
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Term
| What is thyroxine-binding protein? |
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Definition
| The major carrier protein for thyroid hormone, binding 70% of the circulating T3 and T4 |
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Term
| Where does most of the conversion of T4 into T3 take place? |
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Definition
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Term
| One thyroid receptor can form a heterodimer with what other type of receptor? |
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Definition
| One retinoid receptor (RXR) |
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Term
| What cells are targeted by thyroid hormone? |
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Definition
| Probably all cells of the body, because it regulates development, growth and metabolism |
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Term
| How does thyroid hormone affect glucose concentrations? |
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Definition
| TH enhances insulin-dependent transport of glucose into cells as well as increased gluconeogenesis and glycogenolysis to generate glucose |
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Term
| Do people develop goiters when theyre hypothyroid, euthyroid, or hyperthyroid? |
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Definition
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Term
| What is Hashimoto's thyroiditis? |
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Definition
Acquired autoimmune hypothyroidism; antibodies are directed against thyroglobulin and thyroid peroxidase; the inflamed gland undergoes structural damage, gland destruction, and the development of goiter
Most common cause of hypothyroidism in the US |
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Term
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Definition
| When tissue is exposed to excessive thyroid hormone as in Graves disease; elevated levels of T3 and T4 short circuit the standard feedback loop between the thyroid gland-hypothalamus-anterior pituitary |
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