The countercurrent multiplier system, what is required.
Water leaving loop must be removed from medulla: if water leaving the descending limb stayed in medulla then the "salty" environment would be diluted out. NaCl transported out of loop must remain in the medulla: the Na & Cl ions transported out the ascending limb must stay in the medulla making the medulla salty.
Aquaporin Distribution by the Nephron
LOOK AT POWERPOINT FOR RIGHT DIAGRAM
Na+ Regulation: Renin-Angiotensin-Aldersterone System P2
angiotensin I is conv. to agniotensin II by angiotensin-converting enzyme (ACE) at lungs. angioptensin II stimulates adrenal cortex, which releases aldosterone. Aldosterone upregulates Na+/K+ pumps in DCT,CD
Vasa Recta: Peritubular capillaries around the loop of Henle. STUDY THE VASA RECTA IN THE DIAGRAM
The role of Urea in Urine Concentration
Urea diffusing out the Collecting Duct and into medulla functions as a solute, helping maintain the salty environment. Urea Transports are expressed along the CD. Expression is regulated by Vasopressin (ADH)
What is gout?
Gout is a disorder due over production of Uric Acid, a diff. nitro. waste prod.Uric acid is not water soluble. this acid can appear in various joints but usually the big toe, and can cause inflammation and extreme pain.
concurrent exchange in vasa recta
Descending: permeable to NaCl/urea. Limited permeability to H2O. Ascending: permeable to NaCl. Permeable to H2O
Water Vol. Regulation: effects of ADH on Aquaporins
ADH: Anti-diuretic Hormone
ADH is secreted bny posterior pituitary in response to dehydration.It also stimulates expression of AQP2,3,4 at Collect Duct.
Kidney stones
commonly calcium oxalate can be calcium phosphate or even uric acid.
Concurrent Exchange
Na+ Regulation by Kidneys: Ivolves the Juxtaglomerular Aparatus
Consist of macula densa & glanular cells. Region where afferent arteriole comes in contact w/ thich ascending limbs/DCT
water enters the ascending segment of the vasa recta by osmosis. what is the source of the water?
Na+ Regulation: Renin-Angiotensin-Aldersterone System P1
Low Na+ causes blood vol. decrease, which stimulate macula densa cells to release prostaglandis. this stimulates Granular cells to release renin into blood. Renin converts angiotensinogen to angiotensin I