Renal System Part 1: Schoenwald Flashcards
what are the functional units of the kidney?
Nephrons
Approx. __ million nephrons per kidney
1 million
Nephron is composed of:
- Glomerulus
- Proximal tubule
- Loop of Henle
- Distal tubule
- Collecting Duct
Kidneys: What is the name of the artery that brings blood to the nephron? ( aka blood enters from the renal artery into the _____ _______)
- Afferent arteriole
Kidneys: What is the name of the artery that brings blood out of the nephron?
- Efferent arteriole. (‘E’ for exit)
Kidneys: Substances up to what size can pass through renal capillaries?
40K daltons
Kidneys: (T/F) Larger substances (i.e. protein, RBCs) usually do not pass.
- True
Main Fx of the nephron?
filtration
Kidneys: (T/F) If there is pathology at the nephron level, there could be vasodilation and permeability.
True
Nephron: Function of the PCT (Proximal convoluted Tubule)?
Reabsorbs large quantities of…
- H2O
- Glucose
- Uric acid
- Na+
- Cl-
- HCO3
(hint: GUN (glucose, uric acid, and Na) + HCB (h20, cl, bicarb)
Nephron: Function of the Loop pf Henle?
reabsorbs Na,Cl and H20
Nephron: what is the fx of the distal tubule?
controls excretion of Na, K, HC03 and H into collecting duct
Nephron: Function of the collecting duct?
- Regulates amount of water in the urine due to effect of Antidiuretic hormone (ADH)
Nephron: Substance enter through _______ ______or from interstitial space
peritubular blood(secretion)
Nephron: Substances reabsorbed from the tubule back to circulation via the ______ vasculature
peritubular
Renal function tests: list 3
- BUN
- Creatinine
- Urinalysis
(BUC)
BUN stands for..
Blood urea Nitrogen
BUN: normal range
8-20 mg/dl
BUN measures the concentration of ______
nitrogen(urea) in serum
BUN is a marker of _____ metabolism
protein
When is BUN elevated?
Elevations in renal failure but other causes as well (CHF, acidosis)
Creatinine is a catabolic product of ______
creatine
Daily production of Creatinine depends on _____
muscle mass
Creatine is excreted entirely by:
kidneys **it’s directly related to renal function
Normal Creatinine Range
Normal 0.5-1.1 mg /dl
Elevations of Creatinine suggest..
chronicity of renal disease
Doubling of creatinine= ___% decrease in renal function
50%
PEARLS: -the importance of muscle mass?
-**Muscle mass matters -Decreased muscle mass= lower creatinine
Which 2 groups usually have lower creatinine levels assuming no renal disease?
-paraplegics -(or someone with atrophied muscles) -females
When is Glomerular filtration rate considered?
-for proper dosing and treatment decisions
How is GFR most accurately assessed?
*insulin filtration rate
GFR: clinically, ______ clearance is generally the test ordered
Creatinine clearance
Normal Creatinine clearance range in Females
Female=90-107 ml/mn
Normal Creatinine clearance range in Males
Male=107-140 ml/min
Normal Creatinine Clearance range
90-140 ml/min
Creatinine clearance is an approximation of ____
GFR
Creatinine: -is a metabolic product of _____ -Day to day variation?
-muscle creatine –Day to day variation negligible in healthy kidneys
A rise in creatinine is due to (which 2 things?)
-kidney dysfunction or -damage= decrease in GFR
Creatinine Clearance: -what is it used for?
-assessing kidney function in acute or chronic renal failure -Monitoring effects of drug therapy -Monitoring therapeutic drugs and determining dosage
Creatinine clearance requires:
24 hour urine