Urinalysis Flashcards Preview

APES1001 Block 3 > Urinalysis > Flashcards

Flashcards in Urinalysis Deck (27)
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1
Q

Why does the volume & colour of urine produced by the kidney vary so much?

A
  • varies concentration of irony components according to need to conserve water
  • darker color (dehydrated)
  • lighter colour (hydrated)
  • done via ADH (pituitary hormone) which promotes water reabsorption into the blood in the distal tubule
2
Q

Why does urine always contain urea

A
  • urea = product of broken down amino acids from proteins
  • body only uses amount of Protein needed -> rest is broken down
    = body constantly breaking down protein & replacing with others -> urine always contains urea
3
Q

Why are glucose & amino acids reabsorbed in the nephron

A
  • small enough to be filtered from blood at nephron = enter kidney tubules
  • body needs & reuses some substances -> special mechanisms evolved in proximal tubules = reabsorb substances from the blood
4
Q

Why can’t the kidney just excrete the filtered plasma without adjusting its content?

A
  • homeostasis would not be maintained

- water & solute levels constantly fluctuating according to environment

5
Q

Interpretation of results:

Colour

A

Influenced by

  1. Chemical composition
  2. Urine concentration
    - vitamin B = intensely yellow colour
    - normal urine = clear
6
Q

Interpretation of results:

Volume

A
  • water intake

- 2 liters daily

7
Q

Interpretation of results:

Specific gravity

A

(1.005-1.025)

  • reflects ability of kidneys to concentrate urine
  • higher sp = more concentrated urine
    => excretion of large amounts of salt or urea/ conservation of water by the kidney
8
Q

Interpretation of results:

pH

A

(5 to 9)

  • < 7= acidic — large component of meat in diet
  • > 7 = basic — large component of plant-based material in diet & bacterial growth
9
Q

Interpretation of results:

Glucose

A

(<30mg/dL)

  • very small amounts excreted (reabsorbed in proximal convoluted tubule)
  • normally -I’ve in urine
  • positive result indicates more glucose in the blood being filtered than the kidney can reabsorb
10
Q

Interpretation of results:

Protein

A

(<15mg/dL)
- very little protein normally present in the urine = not filtered in glomerulus (proteins too large to be filtered at the glomerulus filtration barrier)
- amino acids reabsorbed in proximal convoluted tubule
- normally: no protein in urine
(If protein):
1. Kidney disease
2. Strenuous exercise

11
Q

Interpretation of results:

Blood

A

Positive test = positive for red blood cells OR haemoglobin

  • either = abnormal
  • test = positive even if no cells are visible under microscope
  • blood:
    1. Trauma to renal tubule, ureter, bladder or urethra
12
Q

Interpretation of results:

Ketones

A
  • normal: no ketones detectable in urine
  • ketones in blood= burning body fat for energy
  • presence in urine:
    1. Ketoacidosis
    2. Fasting
    3. Strenuous exercise
    4. Pregnancy
    5. Metabolic disorder (I.e. diabetes)
13
Q

Interpretation of results:

Bilirubin/ urobilinogin

A
  • bilirubin = normally negative
  • bilirubin & uro = breakdown of red blood cells & recycling of haemoglobin in body
    1. Blood cells may be dying too rapidly
    2. May be reduction in liver function required to recycle normal number of red blood cells
14
Q

Interpretation of results:

Nitrite

A
  • product of bacterial reduction of nitrate
  • indicates presence of bacterial infection
  • normal: no nitrite in urine as urine is sterile
  • painful urination= typical of lower urinary tract (urethra and bladder) infections —> travel up to kidney if left untreated
  • May be sexually transmitted
  • antibiotics used to treat infections
  • bacterial culture = important to guide antibiotic therapy
15
Q

Interpretation of results:

Sediment

A
  • common urine sediment = epithelial cells, blood cells, casts & crystals
  • white blood cells suggest infection
  • small no. Red cells may be present but sig no. Are not
  • presence of crystals = increased risk of forming kidney stones
    —> result from excess o slate in diet (nuts, dark green veggies)
    —> made worse by high concentration/ high pH (causes oxalate to precipitate out of solution)
  • calcium oxalate stones = most common, but Utica acid and certain other minerals can precipitate out of urine
16
Q

Renal artery

A

Carries blood to kidney

17
Q

Renal vein

A

Carries blood away from kidney

18
Q

Ureter

A

Urine drained by ureter from kidney into bladder

19
Q

Renal medulla

A

Tightly packed excretory tubules and associated blood vessels found here

20
Q

Renal pelvis

A

Urine is collected in the inner renal pelvis

21
Q

Renal cortex

A

Supplied with blood by renal artery and drained by renal vein

22
Q

Descending limb of the loop of Henle

A

Reabsorption of water continues as the filtered moves into the descending limb

23
Q

Ascending limb of the loop of Henle

A

The filtrate reached the tip of the loop and then returns to the cortex in the ascending limb

24
Q

Vasa recta

A

Hairpin shapes capillaries that serve the renal medulla including the long loop of Henle of juxtamedullary nephrons

25
Q

Distal tubule

A

Regulates K+ and NaCl concentration of body fluids

26
Q

Glomerulus

A

Ball of capillaries

27
Q

Proximal tubule

A

Reabsorption of water, ions and valuable nutrients from filtrate