Hormonal Regulation Of Nephrons Flashcards
What are the most important hormonal regulators of ion reabsorption and secretion?
Angiotensin II and aldosterone
What does angiotensin do?
Enhances reabsorption of sodium and chloride in the proximal convoluted tubules.
What happens when more sodium and chloride are reabsorbed?
More water is reabsorbed which raises blood volume and pressure.
Angiotensin also stimulates aldosterone release.
What does aldosterone do?
Stimulates the tubule cells in the last prt of the distal convoluted tubules and throughout the collecting ducts to reabsorption more sodium and chloride and secrete more potassium.
What does aldosterone stimulates secretion of potassium accomplish?
Major regulator of blood potassium level, elevated K can cause cardiac arrest or arythmia.
What does ANP do?
Increases glomerular filtration rate, plays a minor role in the reabsorption of sodium and chloride by the renal tubules. Overall effect lowers blood volume and pressure by decreasing water reabsorption.
What is anti diuretic hormone?
Major hormone that regulates water reabsorption is ADH. Operates via negative feedback loop.
What in the hypothalamus stimulates release of ADH from the posterior pituitary when a concentration of water in the blood decreases, or when there is a decrease in blood volume?
Osmoreceptors
What cells does ADH act on?
Tubule cells in the last prt of the distal convoluted tubules and throughout the collecting ducts.
What is the overall effect of ADH?
Raises blood volume
When ADH concentration is maximal how much urine is produced?
As little as 400-500 mL
What do the kidneys produce a large amount of when ADH level is low?
Dilute
What does the parathyroid hormone do?
Stimulates cells in the early distal convoluted tubules to reabsorption more calcium into the blood. Released when there is a lower than normal level of calcium. Also promotes phosphate excretion.
