Lec 12 Flashcards
What does the renal corpuscle consist of
Bowman’s capsule and Glomerulus
Water is filtered at the Bowman’s capsule but needs to be reabsorbed at some point in the nephron. Trace H2O as it travels from the descending aorta to its specific (most likely) point of absorption in the nephron.
Descending aorta, renal artery, segmental a., interlobar a., (cortical radiate a., afferent arterioles,) glomerulus, Bowman’s capsule, proximal convoluted tubule, descending limb of loop of Henle.
What drives water out of the descending limb and into the renal medulla?
Na+ pumped out of the thick ascending limb increases the osmotic concentration slightly in the medulla, causing water to osmose out.
How is the concentration gradient set up in the interstitial space?
By sodium and chlorine ion transport out of the thick ascending limb of the loop of Henle
True or False. There is one proximal convoluted tubule for every collecting duct
False, many proximal convoluted tubules dump into the collecting ducts
How is water permeability controlled at the collecting duct?
By ADH.
How does ADH regulate water osmosis? Targets the DCT and collecting duct.
Increased ADH –> increased water permeability in DCT –> water reabsorption –> increased urine concentration
Water follows sodium. Explain this statement in relation to countercurrent exchange in the nephron.
Na+ is actively pumped out of the thick ascending limb, increasing solute concentration in the interstitial space. Water will want to go to a place with no water. follows sodium
What effect does a diuretic have on the nephron? Does it serve the same function as ADH?
Decreases permeability of water at collecting duct, lose more water, get more dilute urine. No, they are the opposite.
Examples of diuretics: caffeine, beer (hops), capasin (heat in peppers)
Will increased ADH lead to an increase/decrease of blood pressure? How?
increased ADH →
increased water permeability →
increased blood volume →
increases BP
