Editing Thyroid gland
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===TSH and the rest of the family=== | ===TSH and the rest of the family=== | ||
*TSH is closely related to FSH, LH, and hCG. | *TSH is closely related to FSH, LH, and hCG. | ||
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*There is a common alpha-GSU subunit to TSH, FSH, and LH. | *There is a common alpha-GSU subunit to TSH, FSH, and LH. | ||
*There is a unique beta subunit to each of TSH, FSH, and LH. | *There is a unique beta subunit to each of TSH, FSH, and LH. | ||
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*There are many disulfide bridges that hold these hormones together. | *There are many disulfide bridges that hold these hormones together. | ||
===Regulation of TSH by TRH=== | ===Regulation of TSH by TRH=== | ||
*TRH from the hypothalamus stimulates release of TSH '''and PRL''' at the pituitary. | *TRH from the hypothalamus stimulates release of TSH '''and PRL''' at the pituitary. | ||
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*TRH activates the IP3/DAG pathway in thyrotrope cells of the anterior pituitary. | *TRH activates the IP3/DAG pathway in thyrotrope cells of the anterior pituitary. | ||
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===Thyroid development=== | ===Thyroid development=== | ||
*Recall from anatomy that the thyroid develops partially from neural tissue (ectoderm, C cells = parafollicular cells, calcitonin) and partially from the tongue (endoderm). | *Recall from anatomy that the thyroid develops partially from neural tissue (ectoderm, C cells = parafollicular cells, calcitonin) and partially from the tongue (endoderm). | ||
*The parathyroids are also pulled along by the developing thyroid. | *The parathyroids are also pulled along by the developing thyroid. | ||
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*The female thyroid is larger than the male thyroid. | *The female thyroid is larger than the male thyroid. | ||
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===Sodium / Iodide symporter protein (NIS)=== | ===Sodium / Iodide symporter protein (NIS)=== | ||
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*Pendrin is on the apical surface and can move iodide into the colloid via transport coupled with chloride. | *Pendrin is on the apical surface and can move iodide into the colloid via transport coupled with chloride. | ||
*Pendrin is found in the thyroid, the kidney, the lungs, and '''the ears'''. | *Pendrin is found in the thyroid, the kidney, the lungs, and '''the ears'''. | ||
- | **Easy to remember the thyroid and the ears b/c mutations of pendrin cause hypothyroidism and deafness | + | **Easy to remember the thyroid and the ears b/c mutations of pendrin cause hypothyroidism and deafness. |
**Easy to remember the lungs because pendrin is being investigated for allergic reaction medicine. | **Easy to remember the lungs because pendrin is being investigated for allergic reaction medicine. | ||
===Thyroglobulin=== | ===Thyroglobulin=== | ||
*About 1/3 of the 125 tyrosines on the protein are available for iodination. | *About 1/3 of the 125 tyrosines on the protein are available for iodination. | ||
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===Anti-thyroid compounds=== | ===Anti-thyroid compounds=== | ||
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**Monovalent ions block the accumulation of iodide in the thyroid. | **Monovalent ions block the accumulation of iodide in the thyroid. | ||
***Monovalent ions include perchlorate (ClO4-) and thiocyanate (SCN-) | ***Monovalent ions include perchlorate (ClO4-) and thiocyanate (SCN-) | ||
- | **Thiocarbamides block the reactions that organify | + | **Thiocarbamides block the reactions that organify the iodide and also block the reactions that couple the iodinated tyrosine residues of the thyroglobulin. |
**Goitrogens are "any substance (such as thiouracil) that induces the formation of a goiter" per wordnetweb | **Goitrogens are "any substance (such as thiouracil) that induces the formation of a goiter" per wordnetweb | ||
***This may be a general term. | ***This may be a general term. | ||
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*T4 conversion to rT3 is called '''inner ring deiodination (IRD)'''. | *T4 conversion to rT3 is called '''inner ring deiodination (IRD)'''. | ||
*Type 1 deiodinase from the liver is the primary source of serum T3. | *Type 1 deiodinase from the liver is the primary source of serum T3. | ||
- | *Sometimes, when recovering from an illness that is not thyroid related, patients will | + | *Sometimes, when recovering from an illness that is not thyroid related, patients will develope '''"Euthyroid sick syndrome"''' which manifests as low T3 levels and high rT3 levels and is reversible. |
**This is also called '''"low T3 syndrome"'''. | **This is also called '''"low T3 syndrome"'''. | ||
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===Actions of thyroid hormones in mammals=== | ===Actions of thyroid hormones in mammals=== | ||
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*Patched depigmentation of the skin | *Patched depigmentation of the skin | ||
*Clubby fingers | *Clubby fingers | ||
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===Disease models in rats=== | ===Disease models in rats=== | ||
*The WIC-rdw rat has a missense mutation in the Tg gene (thyroglobulin). | *The WIC-rdw rat has a missense mutation in the Tg gene (thyroglobulin). | ||
*Presents as dwarf and models congenital primary hypothyroidism. | *Presents as dwarf and models congenital primary hypothyroidism. |