Loop of Henle Flashcards
What is the nephron?
The functional unit of the kidney
What are the two parts to the loop of Henle?
Descending limb
Thick ascending limb
What is the key function of the loop of Henle?
The thick ascending limb creates a hyperosmolar interstitial space in the medulla to drive water loss from the descending limb and collecting duct
What is the descending limb permeable to?
Water
Why does water leave the descending limb?
Osmotic force
What is the osmotic gradient of the thick ascending limb?
200mOsm.kg
What moves ions out of the filtrate in the thick ascending limb?
Na+/K+/2Cl- cotransporter
abbreviated to NKCC2
It is a cation coupled chloride transporter
What is essential for NKCC2 to work?
K+ recycling through the apical membrane
What is furosemide?
NKCC2 inhibitor
Used in cardiac and renal failure
What is the countercurrent multiplier?
The opposite flow of fluid in the two limbs of the loop of Henle that increases the amount of ions that are reabsorbed
What are thiazides?
Act in the distal tubule
Block Na+/Cl- cotransporters
Used as a diuretic
How is water taken up in the collecting ducts?
Through AQP2
How does water leave the collecting duct?
Through AQP3
What does aldosterone stimulate in the collecting ducts?
Synthesis of Na+/K+/ATPase
Synthesis of Na+ and K+ channels
What is spironolactone?
Acts in the collecting ducts
Blocks the effect of aldosterone
Moderate diuretic
Used in treating heart failure
