Overview of Renal Function and Renal Disease

Question 1

what are the three steps of urine formation?

Answer 1

filtration
selective reabsorption
selective secretion

Question 2

how much of the plasma moves into the filtrate?

Answer 2

about 20%

Question 3

how much blood flow do the kidneys receive?

Answer 3

20% of cardiac output

Question 4

what does the loop of henle create?

Answer 4

hypertonic medullary interstitium

Question 5

what are the two capillary beds in the kidney?

Answer 5

glomerular
peritubular

Question 6

where is 90% of renal bloodflow?

Answer 6

cortex

Question 7

which capillary bed has high pressure?

Answer 7

glomerular: high hydrostatic pressure causes fluid filtration

Question 8

in peritubular capillaries, _________________ favors fluid reabsorption

Answer 8

low hydrostatic pressure

Question 9

what can regulate the respective pressures and rate of glomerular filtration and tubular reabsorption in the capillaries?

Answer 9

adjusting the resistance of afferent and efferent arterioles

Question 10

what are some vascular born insults that can impact the kidneys?

Answer 10

thromboembolism
bacterial emboli
circulating immune complexes

Question 11

what color are acute infarcts?

Answer 11

red

Question 12

what color are chronic infarcts?

Answer 12

white

Question 13

infarcts that affect the cortex and medulla likely involve _________________

Answer 13

interlobar vessel

Question 14

infarcts affecting only the cortex could involve either __________________________

Answer 14

the arcuate or interlobular artery

Question 15

what characterizes acute kidney injury?

Answer 15

sudden loss of renal function over hours or several days
potentially reversible

Question 16

what characterizes chronic renal disease?

Answer 16

renal disease has persisted for months or years
function often progressively declines over months to years
“cure” not generally possible

Question 17

at what age is chronic renal disease common?

Answer 17

generally older animals
congenital or familial disease seen in younger animals

Question 18

what is uremia?

Answer 18

clinical signs associated with kidney failure

Question 19

what are the signs of uremia?

Answer 19

anorexia, depression
dehydration
hypothermia
weight loss (chronic)
nausea
vomiting
diarrhea

Question 20

what do you see with uremic gastropathy?

Answer 20

submucosal arteritis
edema and mast cell infiltration of submucosa
glandular atrophy
fibroplasia
mineralization

Question 21

what does mineralization contribute to?

Answer 21

gastric ulceration
hemorrhage
hematemesis

Question 22

what is uremic enterocolitis?

Answer 22

ulcerative and hemorrhagic lesions in colon
often bloody diarrhea

Question 23

what happens with uremic stomatitis?

Answer 23

halitosis: bad breath
oral ulceration

Question 24

what causes oral ulceration with uremic stomatitis?

Answer 24

vasculitis/arteritis
bacteria in mouth convert urea to ammonia

Question 25

what does renal secondary hyperparathyroidism with CRD lead to?

Answer 25

pathologic mineralization renal osteodystrophy

Question 26

how prevalent is arterial hypertension with chronic renal disease?

Answer 26

50-80% of dogs and cats

Question 27

what are some examples of tissue mineralization with uremia?

Answer 27

uremic frosting uremic pneumonitis uremic endocarditis

Question 28

what material accumulates in an animal or person with gout?

Answer 28

uric acid

Question 29

what predisposes patients with uremia to bleeding?

Answer 29

decreased platelet function with uremia ulcerations abnormal blood vessels

Question 30

what are the consequences to bleeding tendencies with uremia?

Answer 30

ocular lesions brain bleeds gastrointestinal hemorrhage gingival bleeding bruising

Question 31

what is renal gout?

Answer 31

urate crystals in renal tubules

Question 32

what is visceral gout?

Answer 32

coating of chalky white urate crystals on internal organs

Question 33

what is articular gout?

Answer 33

accumulation of uric acid crystals in joints and along tendons

Question 34

what are the uremic effects on the endocrine system?

Answer 34

insulin resistance uremic animals usually sterile

Question 35

what does acute kidney injury result in?

Answer 35

accumulation of metabolic wastes dysregulation of fluid and electrolyte balance acid/base imbalance

Question 36

what are the physical exam findings with an acute kidney injury?

Answer 36

rapid onset of clinical signs depressed, hypovolemia, hypotension +/- fever tachypnea to eliminate CO2 +/- bradycardia +/- enlarged, painful kidneys

Question 37

what can cause ischemia?

Answer 37

severe or prolonged dehydration or hypovolemia thrombosis or infarction

Question 38

what are some causes of intrinsic damage to the kidneys?

Answer 38

nephrotoxins hemoglobin or myoglobin nephropathy (more large animals) infectious agents hypercalcemia

Question 39

what are some infectious agents that can cause intrinsic damage to the kidneys?

Answer 39

leptospira ascending infections

Question 40

what are some postrenal causes of acute kidney injury?

Answer 40

elevated pressure acute blockage decreased flow increases: stone formation and infection

Question 41

what are the four phases of acute kidney injury?

Answer 41

initiation extension maintenance repair

Question 42

what happens in the initiation phase of acute kidney injury?

Answer 42

insult and sublethal injury

Question 43

what happens in the extension phase of acute kidney injury?

Answer 43

injury continues and epithelium undergoes apoptosis or necrosis progressive decrease in GFR, urine concentrating ability and urine output blood test may be normal for 1-2 days changes in urine sediment maybe kidneys may be swollen and painful

Question 44

what might you see on a UA during the extension phase?

Answer 44

casts accumulation of things absorbed: glucose or protein etiology evidence

Question 45

what are some things that would be evidence of etiology on a UA of acute kidney injury during the extension phase?

Answer 45

calcium oxalate crystals RBC, WBC, fungi, bacteria

Question 46

what characterizes the maintenance (oliguric) phase of acute kidney injury?

Answer 46

irreversible epithelial damage: GFR reduced enough to show azotemia, urine output decreased complications of uremia develop elimination of inciting cause does not alter rate of recovery

Question 47

what happens during the recovery phase of acute kidney injury?

Answer 47

repair and regeneration of kidney tissue

Question 48

what is the duration of the recovery phase of acute kidney injury?

Answer 48

days to months

Question 49

what is the most common type of renal disease in cats and dogs?

Answer 49

chronic renal disease

Question 50

what has occured in chronic renal disease?

Answer 50

irreversible, structural changes: loss of nephrons and decreased GFR

Question 51

what are some causes of chronic kidney disease?

Answer 51

any cause of AKI familial/congenital infectious disease neoplasia glomerulopathies idiopathic obstruction

Question 52

what are the physical exam findings associated with chronic renal disease?

Answer 52

thin, poor hair coat depressed, dehydrated pale mucous membranes signs of hypertension and uremic changes +/- fever tachypnea to eliminate CO2 +/- small, irregular kidneys

Question 53

when does chronic interstitial fibrosis occur?

Answer 53

end-stage severity of fibrosis correlates with rate of disease progression

Question 54

how many times per day is the entire plasma volume filtered?

Answer 54

60x

Question 55

what is the function of cortical peritubular capillaries?

Answer 55

reabsorption and secretion of substances

Question 56

what is the function of vasa recta capillaries surrounding juxtamedullary nephrons?

Answer 56

osmotic exchangers for production of concentrated urine

Question 57

is uremia associated with the degree of kidney dysfunction or the duration?

Answer 57

degree

Question 58

what is the pathophysiology of uremia?

Answer 58

retention of nitrogenous wastes increased intracellular Na and water decreased intracellular K increased levels of bioactive substances normally metabolized or excreted by the kidney decreased levels of hormones and other mediators produced by the kidney imbalance between calcium and phosphorous

Question 59

what leads to the local effects of uremia on vomiting?

Answer 59

uremic gastritis elevated serum gastrin back diffusion of HCl and pepsin into stomach wall

Question 60

what leads to the central effect of uremia on vomiting?

Answer 60

activation of chemoreceptor trigger zone in brain medulla

Question 61

what is the pathologic mineralization of renal secondary hyperparathyroidism with CRD?

Answer 61

elevated phosphorous binds Ca CaPhos precipitates into soft tissues which may be damaged/necrotic by uremic toxins

Question 62

what is uremic endocarditis?

Answer 62

sub-endocardial mineralization of right or sometimes left atrium

Question 63

what are the adverse effects of hypertension?

Answer 63

glomerular damage and proteinuria ocular lesions hemorrhages

Question 64

why do you get abnormal blood vessels with chronic renal disease?

Answer 64

mineralization hypertension endothelial damage/vasculitis

Question 65

what are microcrystals of uric acid in gout called?

Answer 65

tophi

Question 66

why are uremic animals usually sterile?

Answer 66

elevated prolactin and luteinizing hormone decreased testosterone, estrogen, progesterone atrophy of germinal epithelium of testicle or ovary

Question 67

what are some things that can lead to severe or prolonged dehydration or hypovolemia?

Answer 67

severe vasculitis pancreatitis gastric torsion addisonian crisis heat stroke

Question 68

how can hypercalcemia cause intrinsic damage to the kidney?

Answer 68

vasoconstriction mineralization

Question 69

acute blockage causes ______________ effect on ability to concentrate urine

Answer 69

reversible

Question 70

true/false: blood tests may be normal during the extension phase of kidney injury

Answer 70

true changes in urine sediment may be seen

Question 71

what hormones may play a factor in the recovery phase of kidney injury?

Answer 71

epidermal growth factor TGF alpha IGF

Question 72

what do high glomerular capillary pressures lead to?

Answer 72

scarring and occlusion of vessels synthesis of mesangial matrix disruption of capillaries leads to proteinuria