10.30: Renal Review Flashcards Preview

MHD V: Renal > 10.30: Renal Review > Flashcards

Flashcards in 10.30: Renal Review Deck (49):
1

What is special about flow of blood in kidney?

Only place in body where blood goes from artery, to capillary and back to artery

2

Where does filtrate go after it leaves glomerulus?

Bowmans capsule

3

Is there much protein in healthy urine?

- No, nearly none is filtered
- Most that is filtered is reabsorbed
- Protein in urine sign of pathology

4

What is Tamm horsfall protein?

- Makes up majority of protein seen in healthy urine
- Serves to prevent clot formation

5

Main factor impacting glomerular filtration?

Hydrostatic pressure in the capillary

6

How is RPF estimated?

- PAH clearance
- Nearly all that enters renal circulation is excreted
RPF = clearance PAH

7

RBF equation?

RBF = RPF / (1-hematocrit)

8

What is the filtration fraction?

FF = GFR./ RPF
*Normally 125/625 ml /min ~20%

9

What happens in decreased RPF?

- RAS system constricts efferent arteriole
- Increase hydrostatic pressure in capillary
- Maintains GFR increase FF

10

What do prostaglandins do to afferent?

Dilate increasing RPG and GFR

11

What do NSAIDs do to afferent arterial?

- Constrict it
- Can cause renal failure

12

What does angiotensin do to efferent arterial?

Constricts

13

How does kidney autoregulate in increased systemic BP?

- Constricts afferent

14

RAS steps?

1. Renin converts angiotensinogen to angiotensin I
2. ACE converts I to II

15

How do ACE inhibitors work?

- Prevent angiotensin from constricting efferent arteriole
- Decreases GC pressure to protect kidney

16

What do dihydropyridine Ca antagonist drugs do?

- Very effective at lowering BP
- But abolish autoregulation of kidney so renal hypertension can occur

17

Best way to measure GFR? How is it normally measured?

- Inulin
- Freely filtered and neither reabsorbed or secreted
****However, measured creatinine clearance is most often used

18

Creatinine clearance calculation?

Clearance = (urine [] * urine flow rate) / plasma []

19

Why is creatinine good measure?

- Byproduct of muscle breakdown
- In steady state, production = excretion

20

What is eGFR?

Estimated GFR

21

What is required for eGFR?

- Steady state level of plasma creatinine
- Cannot be used if renal function is rapidly changing

22

What is relationship between creatinine clearance and plasma creatinine?

- Inversely proportional (C= UV/P)
- If clearance is 100 and plasma is 1
- If plasma 2, clearance would be 50
- If 4, then 25

23

What is creatinine clearance good example of?

GFR

24

Cockroft Gault equation?

(140 - age * weight kg) / 72 * plasma Cr
****Multiply by .85 if female
- Gives us creatinine clearance

25

When is eGFR applicable?

Only if serum creatinine is stable

26

What happens in CDK to creatinine?

- Exponential increase in plasma Cr with time

27

What happens in AKI to creatinine?

- Linear increase
- Drops back to normal if function restored

28

What does amount of Cr in a healthy person depend on?

Directly proportional to muscle mass

29

What is fractional excretion?

- Amount of substance excreted in urine related to amount filtered by kidney
- FE = Amount excreted / amount filtered

30

What is FENa equation?

FENa = (UNa/PNa) * (PCr/Ucr) * 100

31

What is FENa in healthy person?

1%

32

What happens to FENa in decreased GFR?

- Increases
- As long as there is not edema present

33

Where are bulk of solutes reabsorbed?

Prox tubule

34

What happens in loop of henle?

Water goes out diluting filtrate

35

What does ADH do?

Water resorption in collecting ducts

36

What does tubular [] > plasma [] mean?

Item is being secreted

37

What is proximal tubule dysfunction called?

Fanconi syndrome

38

What is fanconi Syndrome?

- Prox tubule disorder with decreased resorption
- Glycosuria
- Hypo P, K
- Metabolic acidosis: Bicarb is buffer
- Proteinuria

39

What is loop dysfunction called?

- Bartter's syndrome
- Salt wasting
- Hypokalemia
- Metabolic acidosis

40

What is bartter's syndrome?

- Loop dysfunction
- Salt wasting
- Hypokalemia
- Metabolic acidosis
***Loop diuretics cause same problems

41

What does distal dysfunction cause?

Gitelman's syndrome

42

What is Gitelman's syndrome?

- Distal disfunction
- Hypokalemia, Mg, Ca
- Thiazides case the same

43

Where is angiotensinogen made?

Liver

44

Where is ACE present?

Mostly lung but kidney too

45

What does angiotensin II do?

- Vasoconstric
- Activate aldosterone

46

Where is EPO made?

Kidney

47

Where is Vitamin D activated?

Kidney

48

What is orthostatic hypertension indicative of?

Volume depletion

49

What should FENa be if volume depleted?

Low