Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Clinical Chem I > Non Protein Nitrogen > Flashcards

Non Protein Nitrogen Flashcards

1
Q

How does non-protein nitrogen arise?

A

From the breakdown of protein and nucleic acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What clears these NPN?

A

The kidneys, and include all substances that contain nitrogen but are not proteins or AAs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where are they analyzed and why?

A

In the blood to assess kidney function.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

List the NPN we are interested in

A

Urea/Blood urea Nitrogen
Creantine
Uric acid
Ammonia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is BUN?

A

Urea is the final product of protein breakdown. BUN measures the amount of nitrogen found as urea in the blood.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is BUN values used for?

A

Evaluating kidney function and perfusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is BUN a primary test for?

A

Renal and hepatic functions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are BUN values greatly affected by?

A

High protein diet

Dehydration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is azotemia?

A

This is a condition of increased BUN of >20mg/dL along with increased Cr.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Identify the causes of azotemia.

A
  • Prerenal causes: Reduced blood perfusion to kidney from shock, dehydration, heart failure
  • Renal: internal to kidney
  • Post renal: obstruction in urinary tract from tumor or kidney stones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is uremia?

A

A toxic condition in which urea is extremely elevated at 150 mg/dL accompanied by renal failure and high Cr.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is uremia usually accompanied by?

A

Loss of all kidney functions and systemic complications.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Identify the complications with uremia

A

Loss of major renal functions(excretory, regulatory, synthetic)
Anemia: no EPO made
Metabolic acidosis: H+ not excreted by tubules
Renal osteodystrophy: no Vit D activation
Hyperkalemia: K+ not excreted by tubules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are symptoms of uremia?

A

Fatigue
Nausea
Vomiting
Uremic frost

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is Cr normal range?

A

~0.5-1.4 mg/dL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is Cr?

A

Creamtine is a metabolic breakdown product of muscle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How is Cr concentration in blood?

A

Stable and proportional to muscle mass.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Why is Cr better than BUN?

A

Cr is not affected by diet as BUN is

19
Q

What is Cr used to assess?

A

Glomerular filtration rate GFR

20
Q

What is GFR?

A

An estimated measurement of how much urine filtrate is produced by glomerula per minute.

21
Q

What is GFR a sensitive indicator for?

A

Kidney function

22
Q

How is Cr limited?

A

Cr is limited by increased/deceased muscle mass

23
Q

What is indicated from increased Cr and decreased GFR?

A

Poor kidney function

24
Q

What is the normal range of BUN-Cr ratio?

A

6-20

25
Q

What’s BUN-Cr ratio used for?

A

Determining causes of azotemia

26
Q

What advantage does urea have over creantinine although it is more accurate from not being affected by diet.

A

Urea is increased earlier in renal disease than Cr.

27
Q

What does high ratio of >20 BUN-Cr ratio of increased BUN and normal Cr indicate?

A

Prerenal causes of azotemia like CHf, dehydration, increased protein

28
Q

What does normal ratio of BUN-Cr with increased BUN and increased Cr levels indicated?

A

Renal disease: glomeruloneohrititis, nephrotic syndrome, uremia

29
Q

What is the formula for calculating Cr clearance?

A

(Urine Cr)(Volume Urine in mL/min) / (Plasma Cr)

30
Q

What is the correlation between Cr clearance and renal function?

A

The lower the Cr clearance, the worse renal function is.

31
Q

What is Uric acid?

A

This is a substance produced along side urea by the liver as a byproduct of the breakdown of proteins and nucleic acids.

32
Q

What nucleic acids specifically are broken down to make Uric acid?

A

Purines, AGs

33
Q

Where is UA excreted?

A

In intestines and kidneys, but 90% is reabsorbed.

34
Q

What percentage of NPN is UA?

A

~20%

35
Q

What is hyperuricemia?

A

Over production of uric acid.

36
Q

What caused hyperuricemia?

A

Overproduction of uric acid
Increased intake of purine rich foods
Increased cell breakdown, cellular injury(chemotherapy)
Undexcretion of uric acid from renal disease

37
Q

When does gout occur in re,action to hyperuricemia?

A

When levels of UA are so high that is precipitates out of solution forming urate crystals

38
Q

What is the most characteristic finding of gout?

A

Urate crystals deposit in joints = arthritis/gout

39
Q

What can happen when these urate crystals deposit naturally in urine?

A

Deposits and UA kidney stones

40
Q

What is ammonia?

A

It is a substance toxic to the brain that forms from the deanimation of amino acids.

41
Q

What does ammonia cause to the brain?

A

Hepatic encephalopathy

42
Q

Can ammonia be excreted directly through kidneys?

A

No, it has to be metabolized in the liver to form urea before being excreted as urea

43
Q

What conditions are seen with severe liver dysfunction and increased blood ammonia?

A

Hepatic encephalopathy
Reye’s syndrome
Chronic liver diseases like cancer, cirrhosis, fulminant hepatitis

44
Q

What are the two methods for analyzing Cr?

A
  • Jaffee reaction: Cr + picric acid = orange red chromogen in alkaline solution.
  • Enzymatic methods (increased specificity)

Clinical Chem I (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions