Endocrine Flashcards
How is calcium regulated?
PTH
calcitonin
vitamin D
How does PTH work?
Parathyroid
Role is to increase blood ca, reduce blood P, promote bone remodeling, activate vitamin D Stim by hypocalcemia and hyperphosphatemia, inhib by vitamin D Increases ca reabsorption in kidneys, secrete P, increase vitamin D sythin Increase resorption to relase Ca, bind to osteoblasts that activate osteoclasts Inhib P reabsorption, reabsorption of ca and Mg, make more vitamin D in kidney
How does calcitonin work?
Made by C cells
Decreases Ca in blood Decrease bone resorption Secreted with high ca in blood
how does vitamin D work?
Increase ca and P absorption and reabsorption
Modulates bone remodeling Inhib PTH
Describe thyroid hormone release?
Increases metabolic rate, needed for fetal development, important in tissue differentiation/repro funcitons
T3 is active hormone, t4 is precursur; t3 can go to inactive t2=contains iodide Mostly protein bound in circulation TRH goes to TSH to TH Iodide absorbed, incorporated into thryoglobulin, thryoglobulin uptaken by follicular cells, proteases
describe the nature of hormones?
Internal secretions by ductless glands
Carry intercellular communication -Signal cells -Messenger (hormone) -Target cell (receptor)
Can be amines, peptides, steroids
Descirbe hormone signalling and receptors for hyrophillic hormones
Receptors for hydrophillic (peptide and amine) hormones are 7 transmembrane proteins and receptor Tyrosine kinases (peptide hormones, growth factors, cytokines)
Epi, glucagon, calcitonin, ACTH, PTH, TSH, FSH, LH Insulin, leptin, growth hormones Activate second mesengers
describe hormone signaling for lipophillic hormones?
Receptors for lipophillic are in cytoplasm or nucleus, function as transcription factor and lead to protein synthesis (steroids like cortisol, P4, E2, vitamin D, THs
Why is hypophyseal portal system important?
Connects the posterior pituitary to the hypothalamus through the neural tissue
Hypothalamus controls anterior pituitary through the vascular. Portal vessels come from median eminence, system begins and ends in capillaries=portal system
what homones does the hypo make?
TRH, CRH, GnRH, Somatostatin, PRH, GHRH
ADH and oxytocin
What hormones does the AP make?
GH, TSH, ACTH, LH/FSH, prolactin
What hormones does PP make?
ADH and oxytocin
