BIOCHEM 3H03 Lecture Notes - Lecture 21: Thyrotropin Receptor, Peristalsis, Cardiac Output
19 Apr 2019
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Document Summary
Both t3 and t4 produced in thyroid: t4 conversion to t3 in peripheral cells. In kidney and liver: damage to kidney and liver can result in decrease conversion of t4, if you"re sick- your thyroid hormones will be off medical people will not measure it. Hormones have to be present at appropriate concentrations at all stages of development. Fetal brain and skeletal development: some maternal t4 can cross placenta, lack of hormone becomes apparent after birth, lack of maternal iodine in diet = low hormone levels in mother and fetus. Increasing metabolic rate increase o2 and increase cardiovascular system (keep this in mind for excess/deficiency)- they"re gonna be hot/sweat. Cardiovascular: increased cardiac motility, heart rate, and cardiac output. Gi: increased gut motility, increased utilization of substrates for energy. Secretion controlled by negative feedback from t4 and t3 (from thyroid) and by negative feedback from tsh via a short loop. Use: to assess the status of pituitary hyposecretion of tsh.
