Week3-4 Thyroid

The lack of DUOX and TPO can cause hypothyroidism., The thyrocytes take up iodide ions by a secondary active transport mechanism, The iodine ions are needed to be activated to reacte with tyrosine side chains

The Na/I symporter can be inhibited by thiocyanate, TPO produces active iodine from iodine ions

Reverse T3 can be produced from the condensation of MIT and DIT., T3 can be produced from condensation of MIt and DIT, MIT is produced from the iodination of thyrosine.

The colloid thyroglobin is the inactive storage from for the THs., T3 is formed by oxidative coupling of MIT and DIT., Follicular cells produce T3 and T4., T4 and T3 regulate cell basal metabolism and heat.

condensation is catalyzed by TPO in the colloid, the Na I symporter can be inhibited by perchlorate, T3 contains iodine both at the 3rd and 5th positions, Deiodinases remove iodine from MIT and DIT

It stimulates Ca++ signaling in thyroid cells.

increase thermogenesis, increase metabolic rate, argumentation of cv effects of cathecolamines, increased oxygen consumption

Thyroid hormones affect carbohydrate metabolism primarily by their permissive effect., Cardiac output can be increased as an effect of thyroid hormones., TPR can be decreased as an effect of the TH.

TH increases the cholesterol breakdown., Pulse pressure can be increased as an effect of TH., TH stimulate absorption of glucose.

TBG is a protein that binds about 70-80% of T4 in blood plasma., In cold exposure, more T3 and less reverse T3 is generated., The direct hormonal action of T3 is higher than that of T4., 5 deiodinases which catalyze the conversion of T4 to T3 are important regulators of thyroid hormone activity.

exaggraged reflexes, increased irritability, lower body weight

exposure to thyrotoxic drugs, elevated levels of TSH, iodine deficiency, hyperthyroidism, in response to TSH like autoantibodies, in hypofunction of thyroid glamd

myxedema

slow speech, myxoedema, fatigue

50 100

0.02

99.98

99.8

0.2