Non-Protein Nitrogen Compounds (NPNs)

Question 1

What different things can affect the kidney’s function?

Answer 1

Protein intake, salt intake, tobacco, drugs, doctors prescriptions..etc

Question 2

What is the functional unit of the kidney?

Answer 2

The nephron, blood flows into the bowmans cap

Question 3

What substance dissolves the glomerular membrane?

Answer 3

Ethanol

Question 4

T/F: kidney disease can have both acute and chronic phases, acute being destruction of the nephron and chronic being the inflammation of the entire structure (from over working)

Answer 4

False: Acute phase involves the inflammation of the entire structure while the Chronic phase includes the total destruction of the nephron

Question 5

In plasma, what substance has the highest % of total NPN?

Answer 5

Urea, Amino acids make around <5%

Question 6

Where is urea sythesized?

Answer 6

In the liver, the liver also has ammonia which is catabolized and moved out of the body, high ammonia is liver issue marker

Question 7

T/F: the highest concentration of NPN in blood is with BUN

Answer 7

True

Question 8

T/F: BUN releases ammonia that is converted into nitrogen

Answer 8

False, BUN releases nitrogen that is converted into ammonia

Question 9

Ref Range for BUN and 24hr Urine range?

Answer 9

BUN: 6-20 mg/dL
24 hr Urine: 12-20mg/dL

Question 10

what is the range for pre-dialysis in BUN?

Answer 10

40mg/dL (higher than normal range)

Question 11

T/F: 30% of BUN is reabsorbed into the tubules and 40% of the total is excreted

Answer 11

False, 40% is reabsorbed and 40% is excreted (thats what I have written idk)

Question 12

What affects concentration of BUN? list a few examples

Answer 12

renal function,
dietary intake
Protein intake

Question 13

T/F: Urea goes up the ascending limb

Answer 13

true

Question 14

T/F: most urea is excreted/reabsorbed actively and can be used to assess renal function and hydration

Answer 14

False, everything is true besides the fact that it is reabsorbed PASSIVELY

Question 15

What is the definition of Azotemia?

Answer 15

Elevated concentration of urea in blood, usually accompanied by uremia

Question 16

Briefly describe/ID the location of:
Pre renal azotemia
Renal azotemia
post renal azotemia

Answer 16

Pre renal - issues before the kidney (eg heart)
Renal - Kidney (duh)
Post renal - after kidneys (bladder, urethra…etc)

Question 17

Briefly describe Pre-Renal Azotemia, possible diseases associated with, and primary organs involved

Answer 17

Less blood to the kidneys = less urea filtered
Congestive heart failure due to thickening of cell walls
Primary Organs: Heart, brain, lungs

Question 18

T/F: Systolic refers to the shrinking of cardiac walls

Answer 18

false, it is the STRETCHING of cardiac walls

Question 19

Briefly describe Renal Azotemia, possible associated dieases and primary organs

Answer 19

decreased renal function = increased BUN (poor excretion)
renal failure, golm. neph, tube necrosis
LACK OF OXY TO KIDNEY TISSUES

Question 20

T/F: the kidney has two blood supplies, one to filter and one to supply oxygen

Answer 20

true

Question 21

Describe GolmeruloneNephritis (one word? idk)

Answer 21

inflammation of glomeruli and small blood vessels, bacteria or hypertension

Question 22

Briefly describe post-renal azotemia, possible diseases associated and primary organs

Answer 22

obstruction of urine flow
renal calculi (calcium stones)
tumors of bladder or prostate

Question 23

T/F: kidneys can “turn off” when needed

Answer 23

true

Question 24

What are a few things that cause decreased Urea Nitrogen?

Answer 24

low protein intake
liver disease (lack of synthesis)
severe vomiting or poopy
increased protein synthesis

Question 25

T/F: Urease is caused from the hydrolysis of urea to ammonium ions to detect NH4+

Answer 25

true

Question 26

What is the most common method for Urea Nitrogen?

Answer 26

Coupled reaction with urease and glutamate dehydrogenase

Question 27

what is the cofactor for urea nitrogen?

Answer 27

NADH --> NAD+

Question 28

T/F: less NADH = more absorbance more NADH = more BUN

Answer 28

False: Less NADH = less absorbance More NADH = less BUN

Question 29

What must you avoid in urea specimens/requirements?

Answer 29

avoid ammonium and high citrate, susceptible to bacterial decomposition, use quickly or put in fridge

Question 30

T/F: creatine/creatinine is synthesized in the liver from arginine, gylcine and methionine

Answer 30

true

Question 31

What is a high energy source for muscles?

Answer 31

creatine phosphate (kidney biomarker)

Question 32

T/F: creatine phosphate + phosph. acid = creatinine Creatine + water = creatinine

Answer 32

False: Creatine phosphate - phosph. acid = creatinine Creatine - water = creatinine

Question 33

What is creatine kinase used for?

Answer 33

Used to create energy

Question 34

What bodily locations do the following acronyms stand for? CKBB CKMB CKMM

Answer 34

CKBB - brain CKMB - cardiac CKMM - skeletal muscle

Question 35

T/F: creatinine is released into circulation at a steady rate proportional to muscle mass, daily excretion is stable

Answer 35

True, its also good to eval renal function

Question 36

T/F: BUN is influenced by diet

Answer 36

true

Question 37

T/F: elevated creatinine is not found in abnormal renal function

Answer 37

False: it is found in abnormal renal function

Question 38

What does GFR do?

Answer 38

estimates renal function

Question 39

What is creatinine clearance?

Answer 39

amount of creatinine eliminated from blood by kidney per unit of time (usually 24hr)

Question 40

T/F: as plasma creatinine goes up, GFR goes down

Answer 40

true

Question 41

What is the equation for creatinine clearance?

Answer 41

urine creatinine/plasma creatinine x urine vol (ml)/time (min) x 1.73/BSA

Question 42

What is the Jaffe reaction? Kinetic Jaffe?

Answer 42

most frequently used for creatinine, turns red orange on chromogen Kinetic jaffe - rate of change in absorbance measured

Question 43

What does the BUN to creatinine ratio do?

Answer 43

explains where the azotemia is coming from, both BUN and creatinine filtered through glomeruli, BUN is reabsorbed

Question 44

What are the BUN to Creatinine rations for: Pre renal BUN: Post renal BUN: Renal BUN:

Answer 44

pre-renal >20:1 post renal (BUN brings ratio down) 10-20:1 Renal (BUN not absorbed, damaged) <10:1

Question 45

What is the ref range for BUN and Creatinine?

Answer 45

BUN: 7-20 mg/dL Creat: 0.7-1.2 mg/dL

Question 46

If your BUN was 26, and creatine was 4.2, what is your B/C ratio? Pre-renal, renal or post renal?

Answer 46

B/C ratio: 6.19 renal

Question 47

What is the biproduct of purine catabolism?

Answer 47

uric acid (pruine --> MSU --> uric acid) most mammals degrade this to allantonic (idk what this word it tbh)

Question 48

T/F: 70% uric acid is excreted in kidneys, the remaining 30% by GIT (98% reabsorbed by PCT)

Answer 48

true, i dont remember what the acronyms stand for

Question 49

What % of uric acid is filtered out?

Answer 49

6-12%

Question 50

if the concentration of uric acid is >6.8mg/dL what does this mean?

Answer 50

urate crystals are present in tissues, very painful

Question 51

Briefly describe gout, population, Uric acid levels..etc

Answer 51

mostly in men 30-50yrs UA >6.0mg/dL inflammation of the joints, high risk of renal calculi

Question 52

T/F: hyperuricemia usually is asymptomatic, but leads to gout

Answer 52

False: it is asymptomatic but usually does not lead to gout, but if you have gout, you have it (25-30%)

Question 53

Disease correlations: increased catabolism leads to chemo for leukemia and myeloma, what is used for treatment?

Answer 53

allopurinal inhibits xanthine oxolose

Question 54

T/F: chronic renal diease has an elevation of uric acid because of bad filtration

Answer 54

true

Question 55

What is Lesch-nyhan syndrome? What is the deficient enzyme?

Answer 55

self mutilating behaviors, biting tongue/hand banging Def Enzyme in synthesis of purines (too much uric acid) usually younger people

Question 56

What is Hypouricemia?

Answer 56

secondary to severe liver diease, deficient in renal tubular reabsorption too much ALLPURINOL

Question 57

What is fanconi syndrome?

Answer 57

deficient in reabsorption, everything is excreted, its a wasting disease

Question 58

What is the primary method for analytical methods in fanconi syndrome?

Answer 58

uses enzyme uricase to convert uric acid to allantonin

Question 59

Briefly describe ammonia

Answer 59

deanimation of amino acids, readily diffuses across the membrane, free ammonia is toxic, but low presence is normal

Question 60

T/F: ammonia has special collection requirements including hot chain

Answer 60

False, it requires cold chains and is not stable (lasts about 30 min) use quickly!

Question 61

What is Reye's syndrome?

Answer 61

found in children, often preceded by viral infection/brain liver fatty liver w minimal inflammation

Question 62

T/F direct ISE uses a change in pH of solution and when NADH --> NAD+

Answer 62

true