BIOL 1840U Lecture Notes - Duodenum, Adenylyl Cyclase, Collagen
Document Summary
Calcium balance: fast facts, total body store 1000 gm (1kg) ii. ***labs measure total [ca] but hormones only sense ionized ca: calcium balance, ca + po4 (serum) (cid:219, hormones shift this balance, kidney makes the fastest changes b/c it filters blood very rapidly (180 l/day) Hormones regulating ca balance: parathyroid hormone (pth) Ii: function rapidly increases ionize serum [ca] in response to low [ca] 1: phosphate is lost from kidney ( po4, capo4 in bone is mobilized ( resorption) Capo4 (bone: synthesis/ storage/ secretion, chief cells of parathyroid gland synthesize pth, 2 cleavages (1st in er; 2nd in golgi) => active form. [ca] in serum controls release of pth stored in secretory granules iii. Ca => parathyroid gland releases pth in 3-5 minutes sensed by ca sensor: low ca => sensor turns off => [ca] ic & transcription of pth . Ca => pth transcription: binds serpentine pth receptor .
