UUT/LUT Structure, Function, Imaging

Question 1

describe the functions of the kidney (5)

Answer 1

kidney functions:
1. maintain volume and composition of body fluids
2. blood pressure
3. excretes metabolic waste, exogenous drugs and toxins, unrequired/excessive compounds
4. major endocrine organ:
-produces renin, EPO, vitamin D3, PG, kinins
-target of PTH, aldosterone, ADH
5. metabolism: ammoniagenesis, gluconeogenesis

Question 2

differentiate between upper and lower urinary tract signs based on clinical history, physical examination findings, and diagnostic test results

Answer 2

upper urinary tract disease:
-no clinical signs OR
-systemic illness OR
-changes in urine composition

lower urinary tract disease:
-no clinical signs OR
-may be systemically ill OR
-changes in urination

shared (typically):
-clinical
1. no clinical signs (possible)
2. systemically ill
3. change in water intake
4. change in urine and urination
5. GI changes
6. blood pressure changes

diagnostic:
1. UN/creatinine
2. electrolytes
3. metabolic acidosis
4. phosphorous
5. urinalysis findings

NOT shared (typically)
1. LUT signs
2. urinalysis findings
3. imaging

it is possible to have both!!

Question 3

summarize the segments of the nephron and their functions

Answer 3

1. glomerulus: ultrafiltrate (protein and cells not filtered out)
2. proximal convoluted tubule: bulk reabsorption and secretion (65% filtered water)
3. loop of Henle: countercurrent mechanism: reabsorb water and Na+
4. distal convoluted tubule: fine tune solutes and reabsorb water based on aldosterone

Question 4

describe urine output as relates to UUT (3)

Answer 4

1. oligo-anuric: minimal to no urine output
   -<0.5-1.0ml/kg/hr
2. non-oligo-anuric: some but less than normal urine output
   - >0.5-1.0ml/kg/hr
3. polyuric: increased urine output
   -cats: >40ml/kg/day
   -dogs: >50ml/kg/day

normal is:
cats: 10-30 ml/kg.day
dogs: 20-40ml/kg/day

Question 5

describe urine output as relates to LUT (6)

Answer 5

1. pollakuria: small volume of urine
2. stranguria: straining to urinate
3. dysuria: difficulty urinating
4. periuria: inappropriate urination
5. nocturia: urination at night
6. incontinence: unconscious urination

Question 6

what are 3 rule-out for azotemia?

Answer 6

1. prerenal: appropriately concentrated
2. renal: inappropriately dilute
3. postrenal: any USG, clinical signs

need urine specific gravity to assess!

Question 7

describe pre-renal azotemia causes and diagnosis

Answer 7

causes:
1. dietary: high protein intake, GI hemorrhage, catabolism and muscle breakdown
2. reduced renal blood flow: dehydration or poor perfusion

diagnosis:
1. azotemia with appropriately concentrated urine
2. BUN may be much higher than serum creatinine, but not reliable (BUN:creatinine ratio)

Question 8

describe causes and clinical signs of post-renal azotemia

Answer 8

causes:
1. obstruction of urine flow: urethral or bilateral ureteral
2. rupture of urinary tract

all causes result in back pressure transferred to kidneys, impairing
-renal blood flow
-GFR
-tubular function

clinical signs:
-acute abdomen
-no signs until uremia

lab findings: mimics AKI

Question 9

describe renal azotemia

Answer 9

1. primary, intrinsic parenchymal renal disease
   -inability to concentrate at 65% loss
   -azotemia at 75% loss (some cats concentrate despite failure)
2. renal failure characterized by:
   -duration: acute or chronic or acute-on-chronic
   -urine output

Question 10

add in tophat questions