Flashcards in Renal: Urine Concentration and Dilution Mechanisms Deck (27):
Osmoreceptors that sense osmolarity
ADH is released from which Pituitary Gland?
Changes in Blood Osmolarity changes ADH release
What Hormone concentrates Urine?
Which part of the Loop of Henle is the concentrating segment?
Descending limb of Loop of Henle
Which part of the Loop of Henle is the diluting segment?
Thick Ascending limb of Loop of Henle
Thin Ascending limb of Loop of Henle
What is the difference between Nephrons?
Placement and Length of Loop of Henle
Concentrations _____ while moving down Loop of Henle
Increase. Up to about 1200mOsm/L
pumps against 200mOsm gradient. 200mOsm maximum difference between outside and inside (higher on the outside)
Sodium-Potassium-2 Chloride Transporter (mostly on Ascending but some on Descending)
Countercurrent Mutltiplier System
Loop of Henle
Countercurrent Exchanger System
Urea contributes to hyperosmotic medulla. Urea contributes how much of the osmolarity of renal medullary interstitium?
Which parts of the Nephron are relatively impermeable to Urea?
Ascending Limb of Loop of Henle, Distal tubule, and Cortical Collecting Duct are relatively impermeable to urea
Which part of the Collecting Duct is very permeable to Urea?
Inner-medullary Collecting Ducts very permeable to urea (even more so with ADH)
Which parts of the Nephron have some reabsorption to Urea?
Which part of the Nephron Urea diffuses into?
Descending Limb of Loop of Henle
Urea moves in and out of Nephron
Vasa Recta surrounds which type of Nephron?
Peritubular Capillaries surrounds which type of Nephron?
Difference between Vasa Recta and Loop of Henle?
Loop of Henle makes the concentration gradient
Vasa Recta aids the Loop of Henle function, preserves concentration gradient
What helps to preserve hyperosmolarity of the renal medulla?
What are the 2 characteristics of the Vasa Recta?
1. Medullar blood flow is low
2. Vasa Recta serve as countercurrent exchangers
How does the Vasa Recta preserve the gradient?
As solutes move into blood, solutes move back into the interstitium instead of "washing out" gradient
What 4 factors impact Urine Concentration?
1. Plasma level of ADH
2. Osmolar concentration of interstitial fluid surrounding the collecting ducts
3. Urea recycling
4. Vasa recta
Dehydration leads to a more ______ Urine
Concentrated (higher osmolarity)