final exam Flashcards
what fractions of bilirubin are increased in hemolytic disorder?
unconjugated bilirubin
total bilirubin
which fraction might be expected to be inreased in a hepatic disorder?
conjugated bilirubin
in severe hemolytic jaundice, what would be the expected results for bilirubin and urobilinogen in the blood, feces and urine?
urine: greatly increased urobilinogen
feces: increased urobilinogen
blood: increased unconjugated bilirubin
where and fromw hat substance is urobilinogen formed?
bilirubin in intestines
what is another name for prehepatic jaundice?
hemolytic
what is another name for posthepatic jaundice?
obstructive
another name for indirect bilirubin is?
unconjugated
what is another name for direct bilirubin?
conjugated
what is the normal range for total serum bilirubin?
0.2-1.0 mg/dl
what is the normal range for direct bilirubin?
0.0-02 mg/dl
indirect bilirubin is converted to direct bilirubin by conjugation with _____ by the _____
glucoronic acid
liver cells
in what condition is conjugated bilirubin increased?
biliary obstruction
in the jendrassik-Grof method for bilirubin determination, bilirubin reacts with what reagent to form the purple compound azobilirubin?
diazetised sulfunilic acid
in the Jendrassik-Grof method what reagent is used to dissolve free bilirubin?
caffeine
in the Evelyn-Malloy method for bilirubin, quantitation of the bilirubin is made by measuring _____
azobilirubin
what reagents are used in the Watson-Schwartz test?
erlich’s reagent
chloroform
sodium acetate
N-Butanol
how are porphobilinogen and urobilinogen distinguished from each other since both form a colored compound with p-aminobenzaldehyde?
prophobilinogen is extracted by the chloroform
in the synthesis of heme, what is the direct precursor of porphobilinogen?
DELTA ALA
why is the stool clay-colored in obstructive jaundice?
urobilinogen is absent because of blockage
to what compound is free bilirubin in the plasma attached?
albumin
what compound is the precursor of uroporphyrin, coproporphyrin, and protoporphyrin
porphobilinogen
if you know the total bilirubin and the conjugated bilirubin values, how can you determine the value for the unconjugated bilirubin?
total minus conjugated
name the three enzymes involved in heme synthesis that are inhibited by lead.
delta ALA synthase
porphobilinogen deaminase
ferrochelatase
what is the composition of Erhlich’s reagent
diazotized fulfanilic acid
why is unconjugated bilirubin NOT found in the urine
because it is not water soluble
what color is urine which contains large amounts of porphyrins?
port wine or magenta
increased bile pigments in the body causes the condition of_____
jaundice
in bilirubin methods, total bilirubin develops a color only after the reagent_____ is added
methyl alcohol
what is the biochemical defect associated with Gilbert’s disease?
defective transportation of bilirubin from liver cells to plasma due to decreased activity of the enzyme gluconyl transferase
what is the most common condition leading to porphyrinuria?
lead poisoning
what normal substances result in the formation of bilirubin when it is broken down?
hemoglobin
what substance is increased in the urine of patients with lead poisoning?
delta ALA
why is bilirubin unstable once the specimen has been centrifuged?
light sensitivity
what observation is used to determine urinary porphyrins
pyrol ring
what specific pigment is possible for the of normal adult feces?
urobilinogen
what is indicated by the presence of lactic acid in duodenal contents?
acute/chronic gastritis
stomach carcinoma
a sweat chloride is done to check for disorders of what organ?
pancreas (but really cystic fribrosis)
what value for sweat chloride is indicative of cystic fibrosis?
60-200 meq/L
in what test is an ion-exchange resin used
diegnese blue
in what conditions is the gastric acidity low or absent?
gastric carcinoma
what is the normal pH of gastric juice after stimulation by a test meal?
1.5-4.0
duodenal fluid testing is used to diagnose diseases of the ____
pancreas
what substance is used to induce sweating in sweat chloride analysis?
pilocarpine
in the sweat test, what should be the NEXT step once the electrodes are removed?
remove gauze and weigh it
what is measured by the Diagnex blue test?
gastric juices,
free HCL
what organ, besides the intestinal tract, for the Diagnex blue test must be properly functioning?
kidneys
to be filtered and interpreted
what is included in the determination of total gastric acidity?
free Hcl combined acidity
what is the composition of topfer’s reagent
dimethylaminobenzene
toxic effects from the ingestion of rat poison can occur due to the presence of ____
chloride
ferric ions are used in the detection of which common drug
salicylates (aspirin)
what poisons are tested for by the Reinsch test?
arsinic and mercury
why should you avoid contact with mercury?
exceedingly toxic and can be absorped through the skin
what is the sample of choice for most cases of poisoning?
urine
what specimens are preferred in cases of arsenic poisoning?
hair/nails
what level of carboxyhemoglobin can be found in cigarette smokers?
5-15 %
what is the purpose of the Trindar reaction?
to detect salicylates
acetaminophen (tylenol) is particularly toxic to the ____
liver
what enzyme is used to determine ethanol levels?
alcohol dehydroganase
what is an oncofetal antigen
a protein shown to exist in both fetal tissue and cancer cells
which tumor marker is used to detect prostatic cancer?
PSA
which tumor marker is used to detect testicular cancer?
AFP
beta-Hcg
what color is the blood in cases of carbon monoxide poisoning?
bright cherry red
what enzyme is decreased in insecticide poisoning?
pseudocholinesterase
name the point-of-care test that is useful in the diagnosis of congestive heart failure
BNP
name one cardiac marker that is used int he triage cardiac panel the specimen for which can be collected in the ER by fingerstick
troponin
what does AFP stand for?
alphafetoprotein
what does CEA stand for?
carcinoembryonic antigen
name the metabolites of epinephrine, norepinephrine, and dopamine
metanephrine
normetanephrine
VMA
homovanilic acid (HVA)
in the determination of 17-ketosteroids, what is Zimmerman reagent composed of?
metadinitrobenzene
the renal excretion of sodium, which in turn affects serum levels, is controlled by hormones produced where?
adrenal cortex
what is the major hormone responsible for water/electrolyte balance?
aldosterone
explain laboratory findings, in regards to thyroid hormones and TSH, in hyperthyroidism and hypothyroidism
hyper- increased thyroid hormones and decreased TSH
hypo- decreased thyroid hormones and increased TSH
1-nitroso-2-napthol is use din the analysis of which amine metabolite? what amine is this a metabolite of?
5-HIAA
serotonin
where would you find a pheochromocytoma?
adrenal medulla
urinary 17-ketosteroids may be elevated in diseases of which endocrine gland?
adrenal gland
briefly explain the Pisano method. what is it used to measure?
acid hydrolysis and absorption on an ion-exchange resin is followed by elution with ammonium hydroxide. Resulting compound is converted to vanilin and reacted with periodate. colored product of the reaction is measure spectrophotometrically. with VMA, sodium metaperiodate is used but measruement performed the same as other catecholamines.
give a brief description of graves disease
is it an autoimmune disorder that occurs 6x more frequently in women than men. frequency in general population about 0.04% Ab’s stimulate thyroid binding to TSH receptors causing diffuse hyperplasia of the thyroid lab results indicate:
increased T3, T4, FT4I, T3U
decreased or normal TSH
may have exopthalmia and goiter
what is the first and best indicator of hyper- or hypothyroidism
TSH
what are the catacholamines?
epinephrine,
norepinephrine
dopamine
which hormones dos the thyroid gland produce?
calcitonin
T3
T4
what is another name for epinephrine
adrenalin
to which amino acid does the thyroid gland bind inorganic iodide from the plasma
tyrosine
what is the principle function of the pancreas
production of insulin and glucagon
which organ is the major site of steroid metabolism
liver
briefly explain addison’s disease
underfunction of the adrenal cortex
decreased output of aldosterone, epinephrine, and cortisol as well as some supplementary sex hormones
it is primary adrenal insufficiency
cushing’s syndrome is also known as
hyperadrenalcorticalism
HCG is produced by the ____ and begins to rise within ____ after conception
placenta
1-2 days
briefly explain the function of vasopressin
stimulates reabsorption of water by the kidney tubules
where is the hormone epinephrine produced
adrenal medulla
argentaffinomas produced elevated levels of what
serotonin
briefly explain the function of oxytocin
site of action = smooth muscle
main functions to stimulate contractions of the uterus during delivery and contractions of breast tissue cells to cause milk ejaculation
what is the site of action for prolactin
mammary glands
in men, 2/3 of all 17-ketosteroids come from the ____ and 1/3 from the ____
adrenals
testes
name some conditions other than pregnancy where you may find increased HCG levels
hydatidiform ole
choriocarcinoma
testicular tumors
what foods should be excluded from the diet for at least two days prior to collecting a urine speciemn for 5-HIAA
bananas avocados pineapple walnuts tomatoes kiwi eggplant
how is most plasma thyroxine found
bound to globulin
what is the chief hormone excreted by the adrenal cortex?
cortisol
the most potent and biologically active estrogen is ____
17-beta-estradiol
what is the action of progesterone
preparation of uterus for ovum implantation
what is the most potent of the biologically active androgens
testosterone
what is the parent substance in the biosynthesis of all adrenal cortical steroids?
cholesterol
of the thyroid iodide hormones, which is the most biologically active?
T3
what hormones regulates the rate of thyroid hormones synthesis and secretion and where is it produced?
TSH
anterior pituitary
briefly explain the negative feedback mechanism in the relationship between cortisol and ACTH
increased cortisol levels cause the hypothalmus and pituitary to decrease production of CRH and ACTH
decreased ACTH causes adrenal glands to decrease cortisol production
