Non-Protein Nitrogen Compounds (NPNs) Flashcards
What different things can affect the kidney’s function?
Protein intake, salt intake, tobacco, drugs, doctors prescriptions..etc
What is the functional unit of the kidney?
The nephron, blood flows into the bowmans cap
What substance dissolves the glomerular membrane?
Ethanol
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)
False: Acute phase involves the inflammation of the entire structure while the Chronic phase includes the total destruction of the nephron
In plasma, what substance has the highest % of total NPN?
Urea, Amino acids make around <5%
Where is urea sythesized?
In the liver, the liver also has ammonia which is catabolized and moved out of the body, high ammonia is liver issue marker
T/F: the highest concentration of NPN in blood is with BUN
True
T/F: BUN releases ammonia that is converted into nitrogen
False, BUN releases nitrogen that is converted into ammonia
Ref Range for BUN and 24hr Urine range?
BUN: 6-20 mg/dL
24 hr Urine: 12-20mg/dL
what is the range for pre-dialysis in BUN?
40mg/dL (higher than normal range)
T/F: 30% of BUN is reabsorbed into the tubules and 40% of the total is excreted
False, 40% is reabsorbed and 40% is excreted (thats what I have written idk)
What affects concentration of BUN? list a few examples
renal function,
dietary intake
Protein intake
T/F: Urea goes up the ascending limb
true
T/F: most urea is excreted/reabsorbed actively and can be used to assess renal function and hydration
False, everything is true besides the fact that it is reabsorbed PASSIVELY
What is the definition of Azotemia?
Elevated concentration of urea in blood, usually accompanied by uremia
Briefly describe/ID the location of:
Pre renal azotemia
Renal azotemia
post renal azotemia
Pre renal - issues before the kidney (eg heart)
Renal - Kidney (duh)
Post renal - after kidneys (bladder, urethra…etc)
Briefly describe Pre-Renal Azotemia, possible diseases associated with, and primary organs involved
Less blood to the kidneys = less urea filtered
Congestive heart failure due to thickening of cell walls
Primary Organs: Heart, brain, lungs
T/F: Systolic refers to the shrinking of cardiac walls
false, it is the STRETCHING of cardiac walls
Briefly describe Renal Azotemia, possible associated dieases and primary organs
decreased renal function = increased BUN (poor excretion)
renal failure, golm. neph, tube necrosis
LACK OF OXY TO KIDNEY TISSUES
T/F: the kidney has two blood supplies, one to filter and one to supply oxygen
true
Describe GolmeruloneNephritis (one word? idk)
inflammation of glomeruli and small blood vessels, bacteria or hypertension
Briefly describe post-renal azotemia, possible diseases associated and primary organs
obstruction of urine flow
renal calculi (calcium stones)
tumors of bladder or prostate
T/F: kidneys can “turn off” when needed
true
What are a few things that cause decreased Urea Nitrogen?
low protein intake
liver disease (lack of synthesis)
severe vomiting or poopy
increased protein synthesis
T/F: Urease is caused from the hydrolysis of urea to ammonium ions to detect NH4+
true
What is the most common method for Urea Nitrogen?
Coupled reaction with urease and glutamate dehydrogenase
what is the cofactor for urea nitrogen?
NADH –> NAD+
T/F: less NADH = more absorbance
more NADH = more BUN
False:
Less NADH = less absorbance
More NADH = less BUN
What must you avoid in urea specimens/requirements?
avoid ammonium and high citrate, susceptible to bacterial decomposition, use quickly or put in fridge
T/F: creatine/creatinine is synthesized in the liver from arginine, gylcine and methionine
true
What is a high energy source for muscles?
creatine phosphate (kidney biomarker)
T/F: creatine phosphate + phosph. acid = creatinine
Creatine + water = creatinine
False: Creatine phosphate - phosph. acid = creatinine
Creatine - water = creatinine
What is creatine kinase used for?
Used to create energy
What bodily locations do the following acronyms stand for?
CKBB
CKMB
CKMM
CKBB - brain
CKMB - cardiac
CKMM - skeletal muscle
T/F: creatinine is released into circulation at a steady rate proportional to muscle mass, daily excretion is stable
True, its also good to eval renal function
T/F: BUN is influenced by diet
true
T/F: elevated creatinine is not found in abnormal renal function
False: it is found in abnormal renal function
What does GFR do?
estimates renal function
What is creatinine clearance?
amount of creatinine eliminated from blood by kidney per unit of time (usually 24hr)
T/F: as plasma creatinine goes up, GFR goes down
true
What is the equation for creatinine clearance?
urine creatinine/plasma creatinine x urine vol (ml)/time (min) x 1.73/BSA
What is the Jaffe reaction? Kinetic Jaffe?
most frequently used for creatinine, turns red orange on chromogen
Kinetic jaffe - rate of change in absorbance measured
What does the BUN to creatinine ratio do?
explains where the azotemia is coming from, both BUN and creatinine filtered through glomeruli, BUN is reabsorbed
What are the BUN to Creatinine rations for:
Pre renal BUN:
Post renal BUN:
Renal BUN:
pre-renal >20:1
post renal (BUN brings ratio down) 10-20:1
Renal (BUN not absorbed, damaged) <10:1
What is the ref range for BUN and Creatinine?
BUN: 7-20 mg/dL
Creat: 0.7-1.2 mg/dL
If your BUN was 26, and creatine was 4.2, what is your B/C ratio? Pre-renal, renal or post renal?
B/C ratio: 6.19
renal
What is the biproduct of purine catabolism?
uric acid (pruine –> MSU –> uric acid)
most mammals degrade this to allantonic (idk what this word it tbh)
T/F: 70% uric acid is excreted in kidneys, the remaining 30% by GIT (98% reabsorbed by PCT)
true, i dont remember what the acronyms stand for
What % of uric acid is filtered out?
6-12%
if the concentration of uric acid is >6.8mg/dL what does this mean?
urate crystals are present in tissues, very painful
Briefly describe gout, population, Uric acid levels..etc
mostly in men 30-50yrs
UA >6.0mg/dL
inflammation of the joints, high risk of renal calculi
T/F: hyperuricemia usually is asymptomatic, but leads to gout
False: it is asymptomatic but usually does not lead to gout, but if you have gout, you have it (25-30%)
Disease correlations: increased catabolism leads to chemo for leukemia and myeloma, what is used for treatment?
allopurinal inhibits xanthine oxolose
T/F: chronic renal diease has an elevation of uric acid because of bad filtration
true
What is Lesch-nyhan syndrome? What is the deficient enzyme?
self mutilating behaviors, biting tongue/hand banging
Def Enzyme in synthesis of purines (too much uric acid) usually younger people
What is Hypouricemia?
secondary to severe liver diease, deficient in renal tubular reabsorption
too much ALLPURINOL
What is fanconi syndrome?
deficient in reabsorption, everything is excreted, its a wasting disease
What is the primary method for analytical methods in fanconi syndrome?
uses enzyme uricase to convert uric acid to allantonin
Briefly describe ammonia
deanimation of amino acids, readily diffuses across the membrane, free ammonia is toxic, but low presence is normal
T/F: ammonia has special collection requirements including hot chain
False, it requires cold chains and is not stable (lasts about 30 min) use quickly!
What is Reye’s syndrome?
found in children, often preceded by viral infection/brain liver
fatty liver w minimal inflammation
T/F direct ISE uses a change in pH of solution and when NADH –> NAD+
true
