Quantification of Renal Function

Question 1

Endocrine function

Answer 1

Secret renin by the JG apparatus
Produce and secrete PG and kinins
Produce and secrete erythropoietin

Question 2

Metabolic function

Answer 2

Activate Vit D3 (calcitriol)
Gluconeogensis
Metabolism of insulin, steroids and xenobiotics

Question 3

Excretory Function

Answer 3

Maintain balance between input and output of water and solute from the body

Question 4

Glomerular filtration

Answer 4

Passive diffusion of water and small ions into the Bowman’s capsule and proximal tubule
Protein bound compounds are too larger and enter the peritubular circulation

Question 5

Define Secretion

Answer 5

Primarily through the proximal tubule via active transport

Anionic and cationic transporters

Question 6

Anions

Answer 6

Probenicid

Penicillin

Question 7

Cations

Answer 7

Creatinine
Cimetidine
Procainamide

Question 8

Define Reabsorption

Answer 8

Water a solute occurs throughout the nephron

Drug occurs along the distal tubule and collecting tubules

Question 9

Highly ionized compounds are

Answer 9

NOT reabsorbed unless pH changes within the urin

Question 10

Intact Nephron Hypothesis

Answer 10

Renal disease is the net result of REDUCED NUMBER OF APPROPRIATELY FUNCTIONING NEPHRONS but remaining nephrons compensate

Question 11

Single Nephron GFR

Answer 11

Increases in the remaining nephrons and the whole kidney GFR represents the sum of SNGFR of the the remaing functional nephrons

Question 12

Kidney is NOT

Answer 12

one homogenous functioning organ; lots of working parts

Question 13

Signs and Symtpoms of Renal Dysfunction

Answer 13

HTN
Edema
Electrolyte imbalance
Anemia
Increase urine output
Metabolic acidosis
Bone demineralization
Hyperkalemia (muscle weakness)
Mental confusion
N/V

Question 14

BUN

Answer 14

Amino acids are metabolized to ammonia then to urea

This process is dependent on protein availability and hepatic function

Question 15

GF reabsorbs how much urea

Answer 15

50% of the filter load in the proximal tubule

Question 16

How does urea pass?

Answer 16

Passive diffusion and dependent on reabsorption of water

Question 17

Normal BUN

Answer 17

5-20 mg/dL

Question 18

Normal BUN:creatinine ratio

Answer 18

10-15:1

Question 19

> 20:1 =

Answer 19

Pre-renal injury (ischemia)

Question 20

Creatinine CANNOT

Answer 20

be reabsorbed if filtered

Question 21

Creatinine is a product of

Answer 21

Creatine metabolism from the muscles and is dependent of muscle mass

Question 22

Noraml Creatinine

Answer 22

0.5-1.5 mg/dL

Question 23

Creatinine elimination

Answer 23

GFR declines = Creatinine increases

Question 24

Jaffe Reaction

Answer 24

Reacts noncreatinine chromogens (not present in the urine) which may result in falsely increased serum creatinine concentrations

Question 25

CrCl =

Answer 25

Urine creation X Urine volume divided by serum creatinine X duration of urine collection

Question 26

Normal CrCl

Answer 26

Men: 90-139 mL/min Female: 80-125 mL/min

Question 27

Physical Factors that may mess with CrCl

Answer 27

``` Age, weight, gender Diet Diurnal variation Drugs (cimetidine, trimethoprim, probenecid) Exercise ```

Question 28

Serum Creatinine concentration is dependent on

Answer 28

Input function/formulation rate and output function/elimination rate

Question 29

Things that can alter serum creatinine

Answer 29

``` Muscle mass Exercise Elderly patietns Diurnal variation Dietary intake of creatine ```

Question 30

Serum Creatinine can rise

Answer 30

50% within 2 hours of meat meal

Question 31

Cystatin C

Answer 31

Synthesized by all nucleated cells at a constant rate May provide and ideal marker of GFR independent of age and gender COSTLY

Question 32

Cystatin C + Corticosteroids for renal transplant

Answer 32

Dose dependent increases in cystatin C

Question 33

Abnormal urinalysis substances

Answer 33

``` Blood Protein Glucose Ketones Urobilinogen Bililrubin WBC ```

Question 34

Urine pH

Answer 34

4.5-7.8 | High pH = bacteria

Question 35

Urine Specific Gravity

Answer 35

1.003-1.030 Weight of an equal volume of urine : water Dependent on water intake

Question 36

Urine Glucose

Answer 36

Normally absent Can be see when serum glucose exceeds 160-200 mg/dL DM detection

Question 37

Urine Ketones

Answer 37

Diabetic ketoacidosis = acetoacetate and acetone in the urine

Question 38

Urine Nitrates

Answer 38

UTI

Question 39

Urine Leukocyte Esterase

Answer 39

UTI

Question 40

Urine Heme

Answer 40

Hemolysis or Rhabdomyolysis

Question 41

Urine Protein or Albumin

Answer 41

30-150mg/day protein | 30 mg/day albumin

Question 42

Albumin is NOT

Answer 42

filtered due to size and negative charge

Question 43

CrCl =

Answer 43

((140-Age)XIBW)/SCr *72 X 0.85 of female

Question 44

IBW

Answer 44

50 kg + 2.3 kg over 5 ft | 45 kg + 2.3 kg over 5 ft

Question 45

GFR

Answer 45

175 X {SCr ^-1.154) X (age^-0.203) X 1.212 (black) X 0.742 (female) Underestimates if GFR is > 50