Renal 1 & 2 Flashcards
Renal Functions
- Excretion of metabolic waste and foreign substances
- Regulation of water and metabolite balance
- Regulation of extracellular fluid
- Regulation of plasma osmolality
- Regulation of red blood cell production
- Regulation of vascular resistance
- Regulation of acid-base balance
- Regulation of vitamin D production
Inulin in relation to GFR
Clearance of inulin = Glomerular Filtration Rate (GFR)
Key Characteristic of Inulin
neither reabsorbed or secreted by kidney
What is renal clearance?
measurement to analyze of kidney
Creatinine in relation to GFR
approximates GFR
Key Characteristic of Creatinine
Freely filtered, 10% secreted
How to detect lower GFR?
higher plasma Creatinine (or BUN)
Which is a more reliable measure of GFR, creatinine or BUN?
Creatinine. It is created from muscle metabolism.
BUN increases after a high protein meal, which makes it less reliable due to it’s fluctuation
What does clearance of PAH approximate?
Renal Plasma Flow (RPF)
Characteristics of Proximal Tubule
-High volume, low-gradient reabsorption
Characteristics of Loop of Henle
- Formation of high interstitial osmolality
- Descending and ascending thin limbs have poorly developed apical and basolateral surfaces
Characteristics of Distal Tubule
low-volume, high-gradient reabsorption
Macula Densa
- Juxtaglomerular Apparatus
- sensor of tubular flow
- well developed basolateral membrane and abundant mitochondria
Characteristics of Collecting Duct
- Concentration/dilution of final urine
- composed of two cell types ( principal and intercalated)
Principal cells
- moderately invaginated basolateral membrane and contain few mitochondria
- play an important role in reabsorption of NaCl and secretion of K+
Intercalated cells
- important role in regulating acid-base balance and high density of mitochondria
- one population secretes H+ (reabsorbs HCO3-)
- second population secretes HCO3-
Renal Blood Flow (RBF)
- 1200 mL/min
- 25% total cardiac output
Renal Plasma Flow (RPF)
-660 mL/min
-
Glomerular Filtration Rate (GFR)
125 mL/min
Peritubular capillaries
- 90% RBF (cortical)
- reabsorption of water and solutes from renal cortex
Vasa recta capillaries
- 10% RBF (8% outer medulla / 2% inner medulla
- reabsorption of water and solutes from renal medulla
Prostaglandins
- renal vasodilation
- regulation of RPF and GRF
