Renal Path

Question 1

What do the kidneys do?

Answer 1

• Excrete waste
• Regulate water and salt balance
• Regulate pH: acid/base
• Endocrine function

Question 2

What endocrine function do the kidneys have?

Answer 2

• Renin
• Erythropoietin
• 1- alpha- hydroxylate production for Ca2+

Question 3

How much do those little bitches way (kidneys)?

Answer 3

150 grams each

Question 4

What are the 4 components of the kidney?

Answer 4

Glomeruli
Tubules
Interstitium
Blood vessels

Question 5

What is synonymous with foot processes?

Answer 5

Podocytes

Visceral epithelium

Question 6

What are the other layers of the capillaries in the glomerulerus?

Answer 6

• Fenestrated endothelial cells

- Glomerular basement membrane

Question 7

What type of collagen monomers make up the GBM?

Answer 7

Type IV collagen

Question 8

What separates foot processes?

Answer 8

Filtration slits

- 20-30 nm

Question 9

What are the slit diaphragm proteins?

Answer 9

Nephrin and Podocin

Question 10

What is characteristic of nephrotic syndrome?

Answer 10

• Protein defects in Nephrin and Podocin

- podocyte fusion

Question 11

What is the origin of Mesangial Cells and Mesangial matrix?

Answer 11

Mesenchymal origin

Question 12

What is the purpose of Mesangial cells?

Answer 12

• Contractile
• phagocytic
• proliferation
• Secrete inflammatory mediators
• lay down collagen

Question 13

what is highly permeable in the glomerular?

Answer 13

Water and lower molecular weight proteins

Question 14

What makes up the juxtaglomerular apparatus?

Answer 14

1. Macula densa
2. Juxtaglomerular cells
3. extraglomerular mesangial cells

Question 15

What is the purpose of the the juxtaglomerular cells?

Answer 15

Secrete renin

Question 16

What is the purpose of the macula densa?

Answer 16

Detects Cl- delivery. Synonymous with Na+ delivery

Question 17

Where are the peritubular capillaries located?

Answer 17

Interstitium

- contains fibroblast like cells

Question 18

What are the categories of renal disease?

Answer 18

• Glomerular
• Tublointerstitial
• Vascular

Question 19

What are the common causes of glomerular pathology?

Answer 19

Immune mediated

Question 20

What is the common cause of tubulointerstitial pathology?

Answer 20

Toxic/ischemic and inflammatory reactions

Question 21

What is uremia?

Answer 21

Azotemia and clinical sx’s

- like gastroenteritis, anemia, neuropathy, pruitis, pericarditis ect

Question 22

What is the classic presentation of nephritic syndrome?

Answer 22

1. Hematuria
2. Mild to moderate proteinuria
3. HTN

Question 23

What is the classic presentation of nephrotic syndrome?

Answer 23

1. > 3.5 gram/day proteinuria
2. hypoalbuminemia
3. edema
4. hyperlipidemia
5. lipiduria

Question 24

What are the classic presentations of acute renal failure?

Answer 24

• Rapid decline of GFR
• Rapid onset Azotemina
• Oliguria or anuria
• Due to glomerular, tubulointerstitial or vascular

Question 25

What is the classic presentation of chronic renal failure?

Answer 25

GFR persistently <60 ml/min/1.73m^2 - at least 3 months - persistent albuminuria

Question 26

What is the classic presentation of renal tubular defects?

Answer 26

- Polyuria - Nocturia - Electrolyte imbalances - Inherited or acquired

Question 27

What is the classic presentation of urinary tract infections?

Answer 27

Pyuria and bacteriuria | Pyelonephritis and cystitis

Question 28

What is the classic presentation of nephrolithiasis?

Answer 28

Renal colic | Hematuria

Question 29

What are the 4 stages of renal dz?

Answer 29

1. Diminished renal reserve 2. Renal insufficiency 3. Renal failure 4. End stage renal dz

Question 30

What is the definition of diminished renal reserve?

Answer 30

GFR around 50% of normal | - Normal range of BUN/CR and asymptomatic

Question 31

What is renal insufficiency?

Answer 31

GFR is 20-50% normal - onset azotemia - anemia - HTN

Question 32

What is renal failure?

Answer 32

GFR <20-25% normal - edema - metabolic acidosis - uremia

Question 33

What is end stage renal disease?

Answer 33

GFR <5% of normal | - terminal stage of uremia

Question 34

What is the best overall measure of kidney function?

Answer 34

GFR -Clearance= UV/P Urine conc.*urine flow/Plasma conc.

Question 35

What are some analytes to measure clearance?

Answer 35

``` Insulin Iothalamate EDTA Iohexol Creatinine ```

Question 36

What can cause extrarenal elimination of Cr?

Answer 36

Bacteria

Question 37

Is Cr perfect for GFR clearance?

Answer 37

no - close but 10-20% is secreted by proximal tubule - serum levels related to body muscle mass and diet

Question 38

What is the estimated creatinine clearance formula?

Answer 38

140-age*weight/72*serum cr (.85 females)

Question 39

How does one calculate MDRD?

Answer 39

175 x (SCr)^-1.154 x (age)^ -0.203 x 0.742 if female, or 1.212 if black Adjusted for body surface area. (ml/min/1.73m^2)

Question 40

What are clearance measurements still used?

Answer 40

- Unsual body habitus- muscle wasting - rapidly changing kidney function - Kidney donors or research protocols

Question 41

What is BUN?

Answer 41

Major end product of protein nitrogen metabolism | - normal is 10-20 mg/dL

Question 42

What affects BUN? Prerenal and increase synthesis of urea?

Answer 42

Catabolism - burns fever and stress - high protein diet - GI bleed - Hemolysis - Maliganancy

Question 43

What increases BUN? Prerenal but decrease renal perfusion?

Answer 43

HoTN/Shock - CHF - Dehydration - Renal vein thrombosis

Question 44

What is a caveat of BUN?

Answer 44

When renin is releases in hypovolemia, this increases aldosterone which causes increased resorption of Na/H2o. - BUN passively follows. Thus increase in BUN which is out of proportion to any change in GFR

Question 45

What are some postrenal increase in BUN?

Answer 45

Benign prostatic hypertrophy - Prostatic carcinoma - tumor of bladder or ureter - retroperiotoneal mass - urinary calculi

Question 46

What are some factors that cause a decrease in BUN?

Answer 46

Decrease synthesis- low protein intake, liver dz | - hemodilution

Question 47

What are factors that can cause hemodilution?

Answer 47

Pregnancy - overhydration - psychogenic polydipsia - DI

Question 48

What is the purpose of creatinine?

Answer 48

Energy storage reservoir for conversion to ATP - usually constant daily excretion - normal is 0.7-1.2 mg/dL - slightly better estimate of GFR than BUN - less affected by kidney perfusion

Question 49

What are some pre-renal increases in creatinine causes?

Answer 49

Increase syn: - muscle hypertrophy - muscle necrosis - anabolic steroid use - high meat diet - intense exercise

Question 50

What are some pre-renal increase in Cr by decrease perfusion?

Answer 50

CHF HoTN Shock

Question 51

What are some post-renal increases in Cr?

Answer 51

Urinary tract obstruction

Question 52

What is a normal BUN:Cr ratio?

Answer 52

10-20 or 15:1

Question 53

What is a common ratio of BUN:Cr in renal dz?

Answer 53

40:4 or 10:1

Question 54

What is a common ratio of BUN:Cr in pre-renal dz?

Answer 54

80:2 or 40:1

Question 55

What is the fraction of excreted Na+?

Answer 55

helps diff between renal dz and pre-renal. | - urine (Na*plasmaCr*100/Urine cr*plasma NA)

Question 56

What favors pre-renal dz?

Answer 56

FeNA <1%

Question 57

What favors ATN?

Answer 57

>2.0% FeNa

Question 58

What is normal protein in the urine over 24 hrs? Whats its make up?

Answer 58

150mg 1. Albumin 2. Small Globulins 3. Tamm-Horsfall protein

Question 59

What are some function things that cause decrease protein in urine?

Answer 59

Heavy exercise cold exposure Fever

Question 60

what are some cause sof proteinuria without Renal dz?

Answer 60

CHF Massive obesity Constrictive pericarditis Renal vein thrombosis