Term
| What are the 5 functions of the kidney? |
|
Definition
1) clearance of waste products
2) water balance
3) conservation of macromolecules
4) electrolyte and acid/base balance
5) endocrine functions: erythropoietin and calcitriol |
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|
Term
| Renal clearance is equal to plasma clearance and provides an accurate estimate of ______. |
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Definition
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|
Term
| What is the gold standard of glomerular filtration? |
|
Definition
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|
Term
| What is the formula for glomerular filtration rate? |
|
Definition
| GFR = [(urine V)(urine Inulin)]/[(plasma Inulin)(time)] |
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Term
| Is urinary excretion of BUN and creatinine GFR dependent? |
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Definition
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Term
| Creatinine has a (constant/cyclic) rate of production by the non-enzymatic breakdown product of phosphocreatinine in ______ tissue and thus is influenced by ______ mass. |
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Definition
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Term
| What are some factors that can inc the rate of production of urea nitrogen? |
|
Definition
-high protein diet
-GI hemorrhage
-protein catabolism
-sepsis
-fasting |
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Term
| ___% of Urea Nitrogen is reabsorbed passively by PCT and ___% is actively reabsorbed by collecting tubules. |
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Definition
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|
Term
| How is urea nitrogen produced? |
|
Definition
| -In GI tract, proteins are metabolized by bacteria to ammonium, absorbed and transported to liver by portal circulation and converted to urea nitrogen |
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Term
| Some urea nitrogen is extreted bia salivary glands into the GI tract. In which animals is it converted back to ammonium and then to UN in the liver (no net excretion)? In what animals is it broken down into AAs (net excretion)? |
|
Definition
-dogs and cats
-ruminants and to a lesser extent horses |
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|
Term
| Does dimethylarginine (SDMA) have a constant or cyclic rate of production? |
|
Definition
-constant
-it is a byproduct of protein methylation |
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|
Term
| What are the 3 main spp of methylated arginine? |
|
Definition
1) monomethylarginine (MMA)
2) asymmetric dimethylarginine (ADMA)
3) symmetric dimethylarginine (SDMA) |
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|
Term
| Symmetric dimethylarginine is excreted (>___%) by what mechanism? |
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Definition
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Term
| True or False: SDMA is more sensitive than sCr for assessing renal dysfunction. |
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Definition
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|
Term
| What are the 3 divisions of azotemia? |
|
Definition
1) pre-renal
2) renal
3) post-renal |
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|
Term
| What is the main mechanism of pre-renal azotemia? Are the nephrons functional? Is urine elimination normal? |
|
Definition
-decreased kidney perfusion
-nephrons are fully functional
-urine elimination is normal |
|
|
Term
Regarding the following, which is the issue with renal azotemia?
a) blood perfusion to kidneys
b) intrinsic renal function
c) urine elimination |
|
Definition
a) normal
b) abnormal
c) normal |
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Term
| In order for renal azotemia to occur, loss of more than ___% of the functional necphrons must occur. |
|
Definition
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|
Term
Regarding the following, which is the issue concerning post-renal azotemia?
a) blood perfusion to kidneys
c) intrinsic renal function
c) urine elimination |
|
Definition
a) normal
b) normal
c) abnormal (rupture/blockage/etc) |
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|
Term
| What are the major clinical signs that would suggest post-renal azotemia? |
|
Definition
-straining, large palpabe urinary bladder (obstruction)
-abdominal effusion with fluid properties consistent with urine (rupture) |
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|
Term
| What 5 things must you have to produce concentrated urine? |
|
Definition
-good hydration
-at least over a third functional nephrons
-medullary interstitium must be saturated
-ADH produced and responsive tubules
-absence of concurrent dz |
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|
Term
| Kidneys reabsorb ___% of water that enters the tubules. |
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Definition
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Term
| The distal tubule is permeable to water in response to what? |
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Definition
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Term
| True or False: As with renal azotemia, the urine is not concentrated. |
|
Definition
| -FALSE, all causes of pre-renal azotemia cuases kidneys to concentrate urine |
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|
Term
| In the case of renal azotemia, what fraction of kidney function must be lost to be unable to concentrate urine. What fraction of kidney function must be lost to lose the ability to clear UN and creatinine? |
|
Definition
-loss of approx 2/3 kidney function
-loss of approx 3.4 kidney function |
|
|
Term
| What are some possible causes of lack of urine concentrating ability? |
|
Definition
-lesions in 2/3 of the kidneys (tubules or interstitium)
-IV fluids
-glucocorticoids
-hypercalcermia
-decreased ADH production or tubule reponse to ADH
-pyometra
-hypokalemia
-hyponatremia (medullary washout)
-solute overload - osmotic diuresis |
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|
Term
| Approx what fraction of the nephrons must not be functional to lose the ability to concentrate urine? |
|
Definition
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|
Term
| True or False: Inorganic phosphate (Pi) may be increased due to reduced to GFR. |
|
Definition
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|
Term
| Describe calcium levels in chronic renal disease. |
|
Definition
-low to low normal
-promotes secondary hyperparathyroidism |
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|
Term
| In what spp is hypercalcemia common? |
|
Definition
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|
Term
| In dogs, when may amylase and lipase elevate? |
|
Definition
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|
Term
| What are the clinical signs of chronic renal disease? |
|
Definition
-PU/PD
-non-regenerative anemia (lethargy)
-GI signs: innappetance, vomiting, diarrhea |
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|
Term
| What does hyperkalemia indicate in urinary disorders? |
|
Definition
-near total shutdown of GFR
-acidosis will contribute |
|
|
Term
| What does hypokalemia indicate in urinary disorders? |
|
Definition
-increased renal loss with polyurina (chronic renal dz)
-cats, cattle |
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|
Term
| What is a common side effect that occurs 2-3 days after relief of obstruction? |
|
Definition
-post-obstructive diuresis
-inc solute load, poor ADH response |
|
|
Term
| Is there usually any permanent kidney impairment with post-renal azotemia? |
|
Definition
|
|
Term
| What are the common physiological side effects of hyperkalemia? |
|
Definition
| -depresses pacemaking and conducting tissues: bradycardia, conduction blocks, cardiac arrest |
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|
Term
| Is K freely filtered throgh the glomerulus? Where is it reabsorbed? Where is it secreted? |
|
Definition
-Yes
-reabsorbed in proximal tubule
-secreted in distal tubule |
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|
Term
| What is the purpose of the water deprivation test? Explain it. |
|
Definition
-to stimulate endogenous ADH production
-if an animal can concentrate its urine with water deprivation psychogenic polydipsia is hte diagnosis |
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|
Term
| When, if ever, is the water deprivation test contraindicated? |
|
Definition
| -in animals that have clinical evidence of dehydration OR are azotemic |
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|
Term
| What do you see inc levels of what during non-glomerular proteinuria? |
|
Definition
| -inc serum concentrations of small, filterable proteins: hemoglobin, myoglobin, Bence-Jones proteins |
|
|
Term
What phsy processes do inc levels of the following suggest in non-glomerular proteinuria:
a) hemoglobin
b) myoglobin
c) Bence-Jones proteins |
|
Definition
a) anemia and evidence of intravascular hemolysis
b) muscle damage
c) monoclonal gammopaty multiple myeloma |
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|
Term
| What are the common causes of proteinuria past the glomerulus? |
|
Definition
-Inflammatory exudate: Cystitis, Pyeloniphritis, Prostatitis, Urethritis, Uteritis
-Hemorrhage |
|
|
Term
| If you have tubular damage caused by non-glomerular proteinuria, what are some common causes and how will they present? |
|
Definition
-Presentation: Azotemia and lack of urine concentration
-acture renal disease and crhonic renal disease |
|
|
Term
| What is glomerular proteinura? How does it present? |
|
Definition
-temporary inc in glomerular permeability
-fever, strenuous excercise, stress seizures, exposure to extreme temperatures |
|
|
Term
| What is pathologic glomerular proteinuria? Describe its lab presentation. |
|
Definition
-glomerular leakage as a result of a disease process (amyloidosis, glomerulonephritis)
-significatn 4+ and hypoalbuminemia |
|
|
Term
| How does glomerular proteinuria typically present? |
|
Definition
| -limb edema and/or ascites |
|
|
Term
| What are the clinical signs of nephrotic syndrome? |
|
Definition
-proteinuria
-hypoalbuminemia
-hypertension
-hyperlipidemia (overproduction or impaired catabolism)
-hypercoagulable (loss of AT, inc platelet function) |
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|
Term
| Urine protein is most sensitive to ______ and detects ______ specifically in cat urine. |
|
Definition
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|
Term
| What do you use to confirm the results of a urine protein? |
|
Definition
|
|
Term
| How can you distinguish actual protein loss via the urinary system from supposed protein loss? |
|
Definition
-urse protien-creatinine ratio (UPC)
-uses a single urine sample and is not affected by volume or specific gravity |
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|
Term
| When do we ignore the results of a urine protein-creaitnine ratio test? |
|
Definition
-if active urine sediment (inflammation)
--significant hematurie, hemoglobinuria, or myoglobinuria |
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|
Term
| What are the advantages and disadvantages of a transurethral catheterization? |
|
Definition
-convenient b/c don't need a distended bladder
-trained personnel
-sedation usually required
-aseptic technique
-risk of iatrogenic UTI
-risk of urethral trauma |
|
|
Term
| Why would you use transurathral catheterization? |
|
Definition
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|
Term
| What are the advantages/disadvatnages of cystocentesis? |
|
Definition
-easy to perform especially if ultrasound guided
-requires trained eprsonnel
-aseptic preparation of site |
|
|
Term
| What is the urine culture collection method of choice? |
|
Definition
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|
Term
| What are some causes of WBC's in the urine? |
|
Definition
-UTI
-neoplasia
-uroliths
-nephroliths |
|
|
Term
| What are some infectious agents that might be seen in a urine sediment? |
|
Definition
-bacteria
-fungi
-parasite ova
-microfilaria |
|
|
Term
| Where do squamous epi cells come from in a urine sediment? |
|
Definition
| -distal urethra, thus present in free-catch and catheterized samples |
|
|
Term
| Where do transitional cells come from in a urine sediment? |
|
Definition
| -renal pelvis, ureters, urinary bladder, urethra |
|
|
Term
| What do high numbers of renal tubule cells in a urine sediment sample suggest? |
|
Definition
| -nephrolith, inflammation, neoplasia |
|
|
Term
| What are the 5 primary factors influencing the formation of crystals? |
|
Definition
1) overhydration of mineral substance
2) pH of urine
3) diat and water intake
4) drugs/toxins
5) refrigeration |
|
|
Term
| Describe the significance of struvites in a urine sediment. |
|
Definition
| -common in dogs, cats, and goats |
|
|
Term
| Describe the significance of calcium carbonate crystals in urine sediment. |
|
Definition
-common in equine urine and occassionally in large ruminants
-not seen in dogs and cats |
|
|
Term
| Describe the significanct of calcium oxalate dihydrate crystals. |
|
Definition
| -common in acidic urine in all spp |
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|
Term
| Describe the significance of calcium oxalate monohydrate crystals. |
|
Definition
| -ethylene glycol toxicity |
|
|
Term
| Describe the significance of bilirubin crystals. |
|
Definition
-inc with hyperbilirubinemia due to extravascular hemoysis or cholestasis
-this can be a normal finding in a dog but NEVER a cat |
|
|
Term
| Describe the significance of ammonium urate (biurate) crystals. |
|
Definition
-significant finding wiwth liver dysfuction - especially portosystemic shutns (PSS)
-can be found in American bulldogs and Dalmations that are healthy |
|
|
Term
| Describe the significance of cystine crystals. |
|
Definition
| -AA metabolism defect (at risk for developing urolith) |
|
|
Term
|
Definition
-mold of tubule lumen, cylindrical shaped, composed of Tamm-Horsfall mucoprotein
-low flow, low pH, concentrated urine favors formation |
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|
Term
| Describe the significance of casts. |
|
Definition
-a few are normal and indicate changes in the tubules although this change may be temporary, minor, and reversible
-inc hyaline casts may be present with proteinuria |
|
|
Term
| Describe the significance of lipid droplets. |
|
Definition
| -common in feline urine but not in any other spp |
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