endocrine - Ca and phosphate homeostasis Flashcards
Bone cell type for production of matrix
Osteoblast
Circulating forms of calcium
Ionized - 50%
Protein-bound - 40%
Complexed with anion - 10%
Bone cell type for resorption of matrix
Osteoclasts
Hormones and minerals found in bones
PTH Vit D Calcitonin Calcium Phosphorus
Predominant parenchymal cell type and a primary endocrine cell of parathyroid gland
Chief/principal cell
Larger, mitochondria-rich, eosinophilic cell type of parathyroid gland
Oxyphil cell
Major regulator of calcium and phosphorus metabolism
PTH
The most important effect of PTH is to increase/decrease plasma calcium level
Increase plasma calcium level
The most important effect of PTH is to increase plasma Ca level by
Stimulate bone resorption
Increase renal tubular reabsorption
Stimulate renal 1,25 dihydroxy- D synthesis
PTH decrease /increase plasma phosphate
Decrease plasma phosphate
PTH decrease plasma phosphate by
Inhibiting renal tubular phosphate reabsorption
Parathyroid cell type that secretes PTH
Chief cell
Primary target of PTH
Bone
Kidneys
PTH receptors
PTH1R (hPTH/PTHrP)
PTH2R
CPTH
Pty receptor that bonds both PTH and PTHrP
PTH1R
PTH receptor that activates adenylyl cyclase and PLC
PTH1R
PTH receptor that is abundant in bones (osteoblasts) and kidneys (prox and distal convoluted tubules)
PTH1R
PTH receptor that does not bind to PTHrP
PTH2R
PTH receptor that is found in brain, placenta and pancreas
PTH2R
PTH receptor that reacts with the carboxylate terminal rather than amino terminal of PTH
CPTH
Primary stimulating signal of PTH
Low circulating Ca level
Low circulating Ca level is sensed by principal cells thru
Ca-sensing receptor (CaSR)
High Mg level inhibits PTH
True
PTH stimulation
Phosphodieasterase inhibitors Epinephrine Dopamine Histamine Lithium Thiazides diuretics
PTH inhibition
A-adrenergic agonists
Prostaglandins
Aluminum
Chromogranin