Renal function

Question 1

What are the three major components of kidney excretion?

Answer 1

• urea
• creatinine
• uric acid

Question 2

What do the kidneys help regulate and how?

Answer 2

• Electrolytes and water – water under control by osmolality and ADH : lytes under control of Aldosterone and Renin
• Acid – Base balance – Excretion of hydrogen ions, excretion/secretion of HCO3

Question 3

What hormones do the kidneys help produce/regulate?

Answer 3

• renin
• erythropoietin
• 1,25 Dihydroxy vitamin D3
• Prostaglandins

Question 4

What does renin respond to?

Answer 4

– responds to changes in fluid volume, blood volume, BP, hyponatremia

Question 5

What does EPO respond to?

Answer 5

• responds to changes in blood O2

Question 6

What is 1,25 dihydroxy vitamin d3?

Answer 6

– Active form of Vit D. Controls Phosphate and calcium balance and bone calcification

Question 7

What are prostaglandins?

Answer 7

cyclic fatty acids that increase renal blood flow, Control renin release, oppose renal vasoconstriction

Question 8

What molecules are allowed through the glomerulus?

Answer 8

• molecules smaller than Albumin allowed to pass through – larger or neg charged molecules cannot pass through
• Lytes, Glu, H2O, Amino acids, low MW proteins, dissolved solutes

Question 9

What substances are regularly reabsorbed in the kidney tubules?

Answer 9

• 75% of H2O, Cl and NA
• 100% of glucose up to renal threshold
• Others – amino acids, vitamins, some uric acid, urea, –Ca, Mg, K and HCO3

Question 10

What substances are passively transferred in the kidney tubules?

Answer 10

h2o and CL

Question 11

What substances are regularly secreted by the kidney tubules?

Answer 11

hydrogen ions and drugs

Question 12

What is the renal threshold for glucose?

Answer 12

160-180 mg/dl

Question 13

Where does water reabsorption happen?

Answer 13

descending limb

Question 14

where does NaCl reabsorption occur?

Answer 14

ascending limb

Question 15

what are common kidney function tests?

Answer 15

• Creatinine
• BUN
• GFR
• uric acid
• ammonia

Question 16

What is 75% of all non protein nitrogen?

Answer 16

urea

Question 17

When will plasma BUN be increased?

Answer 17

• renal disease – is sensitive to changes in renal function but is not specific to the kidney
• Is influenced by diet

Question 18

how do you calculate urea?

Answer 18

Bun x 2.14

Question 19

what is biological variation?

Answer 19

• Random fluctuation around homeostatic set point

- Mean values of various individuals will not be the same and can vary over time

Question 20

What is the creatinine clearance equation?

Answer 20

(u) (v)/p

Question 21

What do you need for correction of the creatinine clearance?

Answer 21

height and weight

Question 22

What are the normal creatinine clearance rates for males and females?

Answer 22

Males – 97-137 ml/min

Females – 88-128 ml/min

Question 23

what is the estimated gfr based on?

Answer 23

Serum Crea

Age, Gender, Race, Body Size

Question 24

what is protein/microalbumin used for?

Answer 24

• should not get through the glomerulus
• Used to monitor diabetics, cardiac disease
• Early sign of kidney damage. Measuring can document progression of disease

Question 25

What can cystatin-c be used for?

Answer 25

-Small protein that is normally cleared by kidney | I-n renal disease it is not cleared

Question 26

what can B2 microglobulin be used for?

Answer 26

- Increase B2 seen in conditions of increased cell turnover, inflammation, renal failure - B2 Microglobulin used to assess renal tubular function in renal transplant patients – Increased could indicate organ rejection

Question 27

what can myoglobin tests be used for?

Answer 27

- Low molecular wt protein associated with skeletal and cardiac muscle injury - Large increase can overload proximal tubules and lead to acute renal failure ( rhabdomyelosis)

Question 28

what can urine electrophoresis be used for?

Answer 28

- Evidence of proteins - Can distinguish acute glomerular neuropathy and tubular proteinuria - Can differentiate proteinuria due to abnormal monoclonal or polyclonal gammopathy

Question 29

what is acute glomerulonephritis associated with?

Answer 29

Often related to group A – beta-hemolytic strep, auto-immune disease or drug mediated

Question 30

what are signs and symptoms of acute glomerulonephritis?

Answer 30

urinalysis-protein and RBC GFR-decreased BUN and creatinine- increased sodium and water retention- increased, can leasd to edema

Question 31

what are the signs and symptoms of nephrotic syndrome?

Answer 31

- hypertension - proteinuria - oliguria - hematuria and rbc casts - hyperlipidemia

Question 32

what would a SPE look like for nephrotic syndrome?

Answer 32

Albumin – decreased Alpha 2 – increased Beta – increased Gamma – may see a decrease

Question 33

What are the key findings of renal tubular disease?

Answer 33

- Decrease reabsorption/secretion of substances - Decrease GFR, loss of Na balance - WBC casts on UA

Question 34

what is the most important manifestation of renal tubular disease?

Answer 34

cannot regulate ph

Question 35

what type of urine cast is considered bad?

Answer 35

waxy cast

Question 36

what can be seen in a urinalysis of an individual that has a uti?

Answer 36

Leukocyte esterase, Nitrites, WBC, Bacteria

Question 37

what effects can a uti have?

Answer 37

Lose the ability to concentrate urine, decrease renal blood flow

Question 38

what are possible causes of acute renal failure?

Answer 38

- traumatic - acute intoxication - part of multiorgan failure - various disease

Question 39

what are possible causes of chronic kidney failure?

Answer 39

- secondary to high blood pressure/diabetes - chronic bacterial infection of the kidneys - cystic kidneys - various autoimmune disease

Question 40

what changes will you see in renal hypertension?

Answer 40

Change in blood volume will stimulate RAAS - increases serum NA+ - increase in urine K+ and H+ - decrease in serum K+