Hormones Flashcards
Is ADH/AVP a protein or steroid?
Protein
What stimulates release of AVP/ADH?
Osmoreceptors in hypothalamus detect an increase in osmolality, releasing ADH
Baroreceptors in the carotid body detect stretch. When no stretch (decreased blood volume) is detected, ADH is secreted
Aside from ADH secretion, what is another action resulting from increased osmolality detected by osmoreceptors?
Increased thirst sensation
What is the origin of ADH/AVP?
Synthesized in the hypothalamus, secreted by neurons in the posterior pituitary gland
What are the actions of ADH/AVP? (6)
- Increase expression of Aquaporin Channels in Principal cells of the Distal Tubule/Collecting Duct
- Constriction of blood vessels
- Inhibits water loss through sweat
- Indirectly promotes K+ secretion
- Promotes urea reabsorption in the inner medullary duct
- Promotes Ca2+ reabsorption in the Thick Ascending Limb of the loop of henle (increases paracellular permeability)
Is aldosterone a protein or steroid?
Steroid
What stimulates release of Aldosterone?
Angiotensin II (RAAS) Increased serum [K+]
What is the origin of Aldosterone?
Adrenal Cortex
What are the actions of Aldosterone?
- Increases Na+ reabsorption (Increases expression of ENaC channels on the apical membrane of Principal cells in the distal tubule/collecting duct
- Increases K+ secretion in the Principal Cells and Beta-Intercalated Cells
- Increases H+ secretion in the alpha-intercalated cells (promotes action of H+-ATPase activity on apical membrane
- Increases K+ secretion into GI and saliva
Is epinephrine a protein or steroid?
Protein
What stimulates release of Epinephrine?
Fight/Flight
What is the origin of epinephrine?
Adrenal Medulla
What are the action of epinephrine in relation to kidney function?
Depends on the receptor
Beta-Catecholamine: Increases activity of Na-K-ATPase (increasing K+ influx into cells, and promoting K+ secretion in the kidney)
Alpha-Catecholamine: Decreases activity of Na-K-ATPase (decreasing K+ influx into the cell and increasing serum K+)
Is insulin a protein or steroid?
Protein
What stimulates release of insulin?
Fed State
What is the origin of insulin?
Pancreas
What are the actions of insulin in relation to kidney function?
Insulin promotes cell uptake of K+ by increasing activity of Na-K-ATPase and promotes K+ secretion.
Is ANP a protein or steroid?
Protein
What stimualtes release of ANP?
Volume expansion/elevated blood pressure
What is the origin of ANP?
Atrial Cardiac Muscle Cells
What are the actions of ANP?
Promote secretion of Na+ in urine
Inhibits the actions of RAAS and ADH
blocks water and salt retention
Is Angiotensin II a Protein or Steroid?
Protein
What signals the release of Angiotensin II?
RAAS
Renin Release stimulated by:
- Low Salt in distal tubule (macula Densa)
- Sympathetics
- Decreased perfusion pressure of the afferent arteriole
What is the origin of Angiotensin II?
Angiotensinogen synthesized in liver
Angiotensin Converting Enzyme formed in the lungs
What are the actions of Angiotensin II?
Promote secretion of Aldosterone
Constricts the efferent arteriole (increasing GFR)
Promotes Na+ reabsorption/H+ secretion
Increases blood volume, blood pressure, blood pH
Is calcitriol a protein or steroid?
Steroid
What signals the release of calcitriol?
Parathyroid Hormone (PTH)
What is the origin of calcitriol?
Proximal tubule
What are the actions of Calcitriol?
Overall: promotes increased serum [Ca2+] and increased serum [Pi]
Binds with VDR (Vitamin D Receptor)
Bone: Increases osteoclastic activity (minerazlization of bone/reabsoprtion of Ca2+)
Intestine: Promote absorption of Ca2+ and Pi
Kidney: Promotes reabsorption of Ca2+ and Phosphate
Is calcitonin a protein or steroid?
Protein
What promotes the release of calcitonin?
Increased serum Ca2+ (Hypercalcemia)
What is the origin of calcitonin?
Thyroid Gland
What are the actions of calcitonin?
Overall: Decrease serum Ca2+ and decrease serum Pi
Bone: Inhibits mineralization/Ca2+ reabsorption by blocking osteoclastic activity and reducing number of osteoclast cells
Kidney: Increase Ca2+ and Pi excretion
Is PTH a protein or steroid?
Protein
What promotes the release of PTH?
Hypocalcemia
What is the origin of PTH?
Parathyroid Gland
What are the actions of PTH?
Overall: Promotes increase in serum Ca2+, decrease in serum Pi
Bone: Promotes osteoclastic mineralization/Ca2+ reabsorption
Intestine: Promotes Ca2+ absorption and Pi absorption indirectly (via action of Calcitriol)
Kidney:
- Promotes Ca2+ reabsorption in the Distal Convoluted Tubule
- Inhibits Pi reabsorption in the Proximal tubule
- Inhibits HCO3- reabsorption
- Promotes Mg2+ reabsorption
- Inhibits H+ secretion (blocks Na/H exchanger)
What does FGF-23 do?
Inhibits Pi reabsorption in the proximal tubule
