Physiology of the Loop of Henle Flashcards
What is the function of the LoH?
generates a cortico medullary solute concentration gradient that enables the formation of hypertonic urine
How does the hyper osmotic medullary intersitial fluid come about?
loop of henle and vasa recta interactions
What are the characteristics of the descending limb in terms of salt and water absorption?
DOES NOT reabsorb NaCl
highly permeable to water
What are the characteristics of the ascending limb in terms of salt and water absorption?
Na and Cl are reabsorbed - upper part - active transport, lower part - passive
impermeable to water
What is the role of the TALH triple cotransporter?
pumps Na, K and Cl out of the filtrate/lumen
What blocks the TALH triple cotransporter?
loop diuretics
What happens to the concentration of tubular fluid in the descending limb?
progressively more concentrated -
What happens to the concentration of tubular fluid in the ascending limb?
progressively more dilute
What is the tonicity of fluid leaving the proximal tubule?
iso osmotic
What is the tonicity of fluid entering the distal tubule?
hypo osmotic
How does urea add solute to the interstitial lumen?
two solute hypothesis
What is the purpose of concurrent multiplication?
concentrates the medullary interstitial fluid - enabling the kidney to produce urine of different volume and concentration depending on ADH levels
What are the characteristics of the vasa recta in relation to NaCl and water?
freely permeable to water and salt
blood flow to the vasa recta is low due to few juxtamedullary nephrons
What is the key role of the vasa recta?
ensures the corticomedullary gradient stays the same
