BR: Nephrology Flashcards
TBW %
60%
ICF/ECF
40/20%
Plasma/interstitial fluid
eCF
Plasma 5%
Interstitial fluid 15%
ECF 20%
Type of collagen of glomerular BM
Type IV
3 filtration barriers of gloemrulus
- Capillary endotheium
- Basement membrane
- Podocytes
Describe JG cells
Juxtaglomerular cells
- at the walls of affferent arteriorles
- secrete renin
Describe macula densa
In distal tubules
Monitor Na concentration in the lumen of DT (and consequently, blood pressure)
Secrete PGE2
Hormones produced in the kidneys
- Kinins
- 1,25- dihydroxycholecalciferol
- Erythropoietin
- Renin
The two diseases that cause tha largest prevalence of kidney dysfunciton are
DM and hypertension
Of those with dm, about ____ % will develop ckd
40%
What forms the juxtaglomerular apparatus
- Macula
- lacis cells
- Renin-secreting granular cells in the afferent aretriole
What are the cells of the collecting duct
Principal and Intercalated cells
Describe principal cells
- predominate
- involved in Na reabs’n and ADH—stimulated water reabs’n
Describe intercalated cells
- also found in distal tubules
- concerned with acid secretion and HCO- transport
Describe the Na-K-2Cl symport
- found in the Thick Ascending Limb of Henle
- one of the basis for countercurrent multiplier
Where is macula densa found?
Early distal tubule
-aka “cortical diluting segment”
Where are principal and intercalated cells found?
Late distal tubule
Describe principal cels 2
- reabsorb Na (and consequently water)
- secrete K
Describe intercalated cells 2
- reabsorb K
- secrete H
Where is the site of action of aldosterone?
Late distal tubule (LDT)
Where is the site of action of ADH?
Collecting duc
MOA of ADH
Inc in AQP-2 channels
Countercurrent multiplier vs exchange
Countercurrent mulitiplier
- loop of henle
- creates “graded osmolarity” in renal medulla
Countercurrent exchanger
- vasa recta
- preserves “graded osmolarity” in the renal medulla
Renal bld flow is __% of cardiac output
25%
Describe tubulo glomerular feedback
Increased fluid in MACULA DENSA —> constriction of nearby AFFERENT arteriole via ADENOSINE
If decreased fluid
- Constricts efferent via Angiotensin II
- Dilates afferent via Nitric oxide
