V-Measurement of Kidney Function

Question 1

clearance equation

Answer 1

Cx = (V x Ux)/Px

clearance = urine flow rate x urine concentration / plasma concentration

Question 2

filtration fraction =

Answer 2

GFR/RPF
glomerular filtration/renal plasma flow

Question 3

if substance completely cleared from plasma

Answer 3

clearance rate = total renal plasma flow

Question 4

if substance freely filtered

Answer 4

rate of excretion = filtration rate

if not reabsorbed or secreted by tubules also

Question 5

measures of GFR

Answer 5

1. inulin- but must be IV, not produced by body
2. creatinine - cleared almost entirely by glom filtration, from muscle metabolism

Question 6

causes of acute kidney injury

Answer 6

1. pre-renal - MI, hypotension, hemorrhage, diarrhea, vomit, sepsis, thrombosis
2. intra-renal - ischemia, toxins, glomerulonephritis
3. post-renal - urinary tract, stones

Question 7

causes of chronic kidney injury

Answer 7

1. metabolic dis - diabetes, obesity
2. hypertension
3. immunologic dis - lupus
4. infection
5. congenital - PCOS

Question 8

renal problems that promote hypertension

Answer 8

1. inc renal vascular resistance via renin-ang or symps
2. dec glomerular cap filtration fraction coefficient
3. xs tubular sodium water re-abs so expand ECF