Renal 1

Question 1

4 renal functions

Answer 1

eliminate metabolic wastes, water and electrolyte balance, acid base regulation, and endocrine (RAA, erythropoietin, vit D)

Question 2

Calcitriol produced from calcidiol by ________ in proximal renal tubular epithelial cells

Answer 2

alpha-1 hydroxylase

Question 3

3 processes that control H2O, electrolyte, and waste excretion are

Answer 3

GFR, tubular resorption, tubular secretion

Question 4

what is the glomerulus? what is the GFR?

Answer 4

glom glom = filtration unit of kidney
glom filtration rate = rate at which blood is filtered through all of glomeruli, and thus measure of overall renal function

Question 5

what are 2 properties of freely filterable substances

Answer 5

small <3.4 nm and positive or neutral charge
eg. albumin is negatively charged, so albuminuria indicates subclinical disease

Question 6

glomerular disease will increase or decrease leakiness

Answer 6

increase

Question 7

renal function: reabsorption occurs in the ________ while secretion occurs in the _________

Answer 7

proximal tubules; distal tubules

Question 8

renal function: what is tubular disease

Answer 8

retention of metabolic wastes; acid base and electrolyte disturbances; inability to concentrate or dilute urine

Question 9

what 3 things does renal concentrating ability depend on (kinda 4 things)

Answer 9

renal interstitium (concentration gradient of NaCl and urea is needed for formation of medullary interstitial osmotic gradient), functional tubules, ADH and ADH responsiveness

Question 10

to dilute urine requires what 2 things

Answer 10

sufficient filtered Na+ and Cl- and active transport in ascending limb

Question 11

concentrate urine requires what 2 things

Answer 11

ADH and concentration gradient (NaCl and urea)

Question 12

what does USG assess?

Answer 12

renal concentrating/diluting ability using a refractive index

Question 13

what is USG range, and what does it depend on

Answer 13

1.001-1.065, depends on hydration status

Question 14

give adequate renal concentrating ability USG values for dog, cat, cow, horse

Answer 14

> 1.030 Dog, >1.035/40 Cat, >1.025 Cow and horse

Question 15

what does isosthenuria indicate?
what is the range on USG?

Answer 15

kidney unable to concentrate of dilute urine, classified as renal azotemia (intrinsic renal disease) when azotemia is present.
1.008-1.012

Question 16

what does hyposthenuria indicate? what is the range on USG?

Answer 16

kidney unable to dilute urine, <1.008

Question 17

what 2 general types of kidney disease exist? can they be differentiated by bloodwork alone?

Answer 17

acute and chronic.
no, need C/S and hx, duration of signs, etc.
exceptions exist, eg. anemia of inflammatory renal disease = CKD

Question 18

if you have pre-renal azotemia, what is USG? what does it mean?

Answer 18

USG > 1.030, so adequate concentrating ability, but there is impaired renal blood flow or decreased perfusion (decreased blood volume) and if left untreated can lead to renal hypoxia and renal azotemia

Question 19

with post-renal azotemia, what is the USG value? what does it mean?

Answer 19

USG variable
distal to nephron obstruction: increased intracapsular hydrostatic pressure/afferent arteriolar constriction that decreases GFR/decreases delivery of waste

Question 20

what does uremia refer to

Answer 20

clinical signs associated with renal failure: V/D, weakness, ammonia smell breath

Question 21

what is the major nitrogenous waste product from mammals? how is is synthesized and excreted?

Answer 21

BUN/urea.
synthesized in liver from CO2 and ammonia via the urea cycle
excreted almost exclusively in URINE
EXCEPT in cattle and horses it is excreted in GI system where it is degraded to NH4+ by enteric bacteria with urease, in rumen and cecum, respectively, then passively absorbed into portal blood as AA or excreted into feces

Question 22

BUN/urea is readily filtered by what? is this passive or active?

Answer 22

glomerulus
passive diffusion to excrete into urine (or in cattle and horses, into GIT then passive diffusion into portal blood as AA or excreted into feces)

Question 23

3 conditions you would see INCREASED BUN/urea

Answer 23

decreased GFR (any reason), increased protein digestion (more in diet or hemorrhage into GIT), protein catabolism due to fever

Question 24

3 conditions you would see DECREASED BUN/urea

Answer 24

decreased production (liver failure or PSS), decreased protein diet/malnutrition, increased excretion, urea cycle enzyme deficiencies, but rare

Question 25

creatinine is produced where (at a constant rate, as a result of normal muscle metabolism)

Answer 25

skeletal muscle. not the same as CK which is a leakage enzyme in cytoplasm of myocytes

Question 26

which enzyme is produced in skeletal muscle at a constant rate as a result of NORMAL muscle metabolism and not reabsorbed (is excreted unchanged by renal tubules or collecting ducts)? which is a LEAKAGE enzyme in cytoplasm of myocytes (not a marker of kidney disease, but a marker of either muscle damage or liver disease)

Answer 26

creatinine; creatine kinase

Question 27

what is azotemia

Answer 27

increased BUN and creatinine. markers of kidney disease

Question 28

***renal failure (aka renal insufficiency or preferred term kidney disease/injury) occurs when ____% of functional renal mass is lost and ______ develops

Answer 28

66-75%; azotemia

Question 29

acute vs chronic kidney disease or injury: which is reversible?

Answer 29

acute is potentially reversible, chronically irreversible. again, can't be diagnosed with lab tests alone definitively because there is considerable overlap

Question 30

assessing kidney disease with creatinine and BUN: what should you consider with increased BUN?

Answer 30

other causes of increased BUN are: - intestinal hemorrhage - increased protein catabolism (generates increased NH4+ this increased BUN production by hepatocytes) (creatinine will be normal and BUN increase will be mild)

Question 31

assessing kidney disease with creatinine and BUN: what should you consider with creatinine?

Answer 31

consider muscle mass

Question 32

assessing kidney disease with creatinine and BUN: what should you consider with creatinine?

Answer 32

consider muscle mass

Question 33

compare serum creatine and serum SDMA: which increases at earlier % function loss? which is more specific? which is more sensitive? which is affected by

Answer 33

both are specific (serum creatinine 100%, serum SDMA 91%) serum creatinine: increase at 75% function loss, NOT sensitive (17%), decreases with age and hyperthyroidism in cats, variable reference ranges serum SDMA: increases at only 40% loss, 100% sensitive, not affected by age, muscle mass, or hyperthyroidism, ONE reference range

Question 34

***can you interpret azotemia properly without USG?

Answer 34

no

Question 35

three components of urinalysis are

Answer 35

physical, chemical, microscopic

Question 36

cylinduria (casts in urine) can be seen with what condition

Answer 36

tubular disease

Question 37

crystalluria can be potential cause of what disease, (but is not a reliable indicator for presence of uroliths/nephroliths)

Answer 37

kidney disease

Question 38

glucosuria in a normoglycemic patient is indicative of what disease

Answer 38

tubular disease

Question 39

is proteinuria in dilute urine a cause for concern that should be investigated

Answer 39

always! (in some healthy dogs in dilute urine can be microalbuminura (small amounts albumin))

Question 40

***hypoalbuminemia in blood is most often associated with what kind of proteinuria?

Answer 40

renal proteinuria

Question 41

what are 3 types of proteinuria? (kinda 4, one please give the two subtypes)

Answer 41

pre-renal (overflox proteinuria) = more small blood proteins get filtered through the glom glom renal proteinuria: glomerular = damage to the glom glom so decreased selective permeability and passage of larger proteins renal proteinuria: tubular = damage to tubules, so smaller proteins that should be resorbed are not post-renal (hemorrhagic and inflammatory proteinuria) = hemorrhage or inflammation in LUT, eg. UTI

Question 42

what is UPC ratio? what does it help to conform?

Answer 42

evaluates loss of protein relative to creatine (since creatinine filtration is relatively constant in healthy animals) helps confirm a renal proteinuria

Question 43

tell me the normal UPC ratio in dogs? what is abnormal (hint: think what the UPC ratio is used to help confirm)

Answer 43

normal is <0.5 remember they help to confirm a renal proteinuria - tubular proteinuria will be >0.4 (if azotemic) or 1-2 (if not azotemic) - glomerular proteinuria >2.0 (more dramatic)