MLT 130 Final Endocrinology, Body Fluids, Toxicology Flashcards Preview

MLT 130 Clinical Chemistry I > MLT 130 Final Endocrinology, Body Fluids, Toxicology > Flashcards

Flashcards in MLT 130 Final Endocrinology, Body Fluids, Toxicology Deck (101)
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1
Q

What fraction(s) of bilirubin is/are increased in a hemolytic disorder?

A

unconjugated

total

2
Q

Which fraction might be expected to be increased in a hepatic disorder?

A

conjugated; direct

3
Q

In severe hemolytic jaundice, what would be expected results for bilirubin and urobilinogen in the urine, feces, and blood?

A

Urine - greatly increased urobilinogen
Feces - increased urobilinogen and urobilin
Blood - increased unconjugated bilirubin

4
Q

Where and from what substance is urobilinogen formed?

A

bilirubin

Bacteria from intestines

5
Q

Another name for prehepatic jaundice is _______.

A

hemolytic

6
Q

Another name for posthepatic jaundice is _______.

A

obstructive

7
Q

Another name for FREE (indirect) bilirubin is _______.

A

unconjugated

8
Q

Another name for direct bilirubin is _______.

A

conjugated

9
Q

What is the normal range for direct bilirubin?

A

0.0-0.2 mg%

10
Q

Indirect bilirubin is converted to direct bilirubin by conjugation with _______ ____ by the ____ ____.

A

glucuronic acid

liver cells

11
Q

In what condition is conjugated bilirubin increased?

A

biliary obstruction

12
Q

In the Evelyn-Malloy method for bilirubin, quantitation of the bilirubin is made by measuring _______.

A

azobilirubin

13
Q

In the Jendrassik-Grof method for bilirubin determination, bilirubin reacts with what reagent to form the purple compound azobilirubin?
In this method, what reagent is used to dissolve free bilirubin?

A

diazotized sulfanilic acid

caffeine

14
Q

What reagents are used in the Watson-Schwartz test?

A
Ehrlich's reagent
Chloroform
N-Butanol
Sodium acetate
(NOT Diethyl ether)
15
Q

How are porphobilinogen and urobilinogen distinguished from each other since both form a colored compound with p-aminobenzaldehyde?

A

Porphobilinogen is extracted by chloroform

16
Q

In the synthesis of heme, what is the direct precursor of porphobilinogen?

A

Delta-aminolevulinic acid (Delta ALA)

17
Q

Why is the stool clay-colored in obstructive jaundice?

A

urobilinogen is absent due to blockage

18
Q

To what compound is free bilirubin in the plasma attached?

A

albumin

19
Q

What compound is the precursor of uroporphyrin, coproporphyrin, and protoporphyrin?

A

porphobilinogen

20
Q

If you know the total bilirubin and the conjugated bilirubin values, how can you determine the value for the unconjugated bilirubin?

A

total - conjugated

21
Q

Name the three enzymes involved in heme synthesis that are inhibited by lead.

A

Delta ALA synthase
Porphobilinogen deaminase
Ferrochelatase

22
Q

What is the composition of Erhlich’s reagent?

A

*Diazotized sulfanilic acid

23
Q

Why is unconjugated bilirubin NOT found in the urine?

A

NOT water soluble

24
Q

What color is urine which contains large amounts of porphyrins?

A

port wine; magenta

25
Q

Increased bile pigments in the body causes the condition of _______.

A

jaundice

26
Q

In bilirubin methods, total bilirubin develops a color only after the reagent _______ _______ is added.

A

methyl alcohol

27
Q

What is the biochemical defect associated with Gilbert’s disease?

A

Defective transport of bilirubin from plasma to liver cells; reduced activity of glucuronyltransferase

28
Q

What is the most common condition leading to porphyrinuria?

A

lead poisoning

29
Q

What normal substance results in the formation of bilirubin when it is broken down?

A

hemoglobin

30
Q

What substance is increased in the urine of patients with lead poisoning?

A

Delta-ALA

31
Q

Why is bilirubin unstable once the specimen has been centrifuged?

A

light sensitivity

32
Q

What observation is used to determine urinary porphyrins?

A

Red fluorescence in UV light

33
Q

What is the basic unit of the structure of porphyrins?

A

pyrrole rings

34
Q

What specific pigment is possible for the color of normal adult feces?

A

urobilin

35
Q

What is indicated by the presence of lactic acid in duodenal contents?

A

Acute or chronic gastritis

stomach carcinoma

36
Q

A sweat chloride is done to check for disorders of what organ?
What value for sweat chloride is indicative of cystic fibrosis?

A

pancreas

60-200 mg/dL

37
Q

In what test is an ion exchange resin used?

A

Diagnex Blue test

38
Q

In what condition is the gastric acidity low or absent?

A

gastric carcinoma

39
Q

What is the normal pH of gastric juice after stimulation by a test meal?

A

1.5-4.0

40
Q

Duodenal fluid testing is used to diagnose diseases of the _______.

A

pancreas

41
Q

What substance is used to induce sweating in sweat chloride analysis?

A

pilocarpine

42
Q

In the sweat test, what should be the NEXT step once the electrodes are removed?

A

remove gauze/filter paper and weigh it

43
Q

What is measured by the Diagnex Blue test?

A

Tubeless test of free HCl in gastric secretions/juices

44
Q

What organ, besides the intestinal tract, must be properly functioning to do the Diagnex Blue test?

A

kidneys

filtered and interpreted

45
Q

What is included in the determination of total gastric acidity?

A

Free HCl and combined gastric acidity

46
Q

What is the composition of Topfer’s reagent?

A

Dimethylaminobenzene

47
Q

Toxic effects from the ingestion of rat poison can occur due to the presence of _______.

A

fluoride

48
Q

Ferric ions are used in the detection of which common drug?

A

salicylates (aspirin)

49
Q

What poisons are tested for by the Reinsch test?

A

Arsenic and mercury
Heavy Metals
NOT Pb

50
Q

Why should you avoid contact with mercury?

A

It can be inhaled or absorbed by the skin - is extremely toxic

51
Q

What is the sample of choice for most cases of poisoning?

A

Urine

52
Q

What specimens are preferred in cases of arsenic poisoning?

A

hair and nails

53
Q

What level of carboxyhemoglobin can be found in cigarette smokers?

A

5-15%

54
Q

What is the purpose of the Tindar reaction?

A

detect salicylates

55
Q

Acetaminophen (Tylenol) is particularly toxic to the _______.

A

liver

56
Q

What enzyme is used to determine ethanol levels?

A

alcohol dehydrogenase

57
Q

What is oncofetal antigen?

A

a protein shown to exist in both fetal tissue and cancer cells

58
Q

Which tumor marker is used to detect prostatic cancer?

A

PSA

59
Q

Which tumor marker is used to detect testicular cancer?

A

Beta hCG

AFP

60
Q

What color is the blood in cases of carbon monoxide poisoning?

A

bright cherry red

61
Q

What enzyme is decreased due to insecticide poisoning?

A

pseudocholinesterase

62
Q

Name the point-of-care test that is useful in the diagnosis of congestive heart failure.

A

BNP

63
Q

Name one cardiac marker that is used in the triage cardiac panel, the specimen for which can be collected in the ER by fingerstick.

A

troponin

64
Q

What does AFP stand for?

A

alpha fetoprotein

65
Q

What does CEA stand for?

A

carcinoembryonic antigen

66
Q

Name the metabolites of epinephrine, norepinephrine and dopamine.

A

Metanephrine(E)
Normetanephrine(N)
Vanillylmandelic acid (VMA)-(E&N)
Homovanillic acid(HVA)- dopamine

67
Q

In the determination of 17-ketosteroids, what is Zimmerman reagent composed of?

A

meta-dinitrobenzene

68
Q

The renal excretion of Na+, which in turn affects serum levels, is controlled by hormones produced where? What is the major hormone responsible for water and electrolyte balance?

A

adrenal cortex

aldosterone

69
Q

Explain lab findings, in regards to thyroid hormones and TSH, in hyperthyroidism and hypothyroidism.

A

hyper-increase T3/T4, decrease TSH

hypo-decreased T3/T4, increased TSH

70
Q

1-nitroso-2-naphthol is used in the analysis of which amine metabolite? What amine is this a metabolite of?

A

5-HIAA

serotonin

71
Q

Where would you find a pheochromocytoma?

A

adrenal medulla

72
Q

Urinary 17-ketosteroids may be elevated in diseases of which endocrine gland?

A

adrenal gland

73
Q

Briefly explain the Pisano method. What is it used to measure?

A

Acid hydrolysis and absorption on an ion-exchange resin is followed by elution with ammonium hydroxide. The resulting compound is converted to vanillin which is reacted with periodate. Colored product of the reaction is measured spectrophotometrically. With VMA, sodium is used but measurement performed the same as other catecholamines.

74
Q

Give a brief description of Grave’s disease.

A

autoimmune disorder 6x more frequent in women. typical symptoms of hyperthyroidism. Abs stimulate the thyroid by binding to TSH receptors causing diffuse hyperplasia. Labs indicate;
increased T3, T4, FT4I, T3U
decreased or normal TSH

may have exopthalmia and goiter

75
Q

What is the first and best indicator of hyper- or hypothyroidism?

A

TSH

76
Q

What are the catacholamines?

A

epinephrine
norepinephrine
dopamine

77
Q

Which hormones does the thyroid gland produce?

A

calcitonin
T3-triiodothyronine
T4-thyroxine

78
Q

What is another name for epinephrine?

A

adrenaline

79
Q

To which amino acid does the thyroid gland bind inorganic iodide from the plasma?

A

tyrosine

80
Q

What is the principle function of the pancreas?

A

production of insulin and glucagon

81
Q

Which organ is the major site of steroid metabolism?

A

liver

82
Q

Briefly explain Addison’s disease.

A

Underfunction of adrenal cortex
decrease output of aldosterone, epinephrine, and cortisol as well as some supplementary sex hormones
it is a primary adrenal insufficiency

83
Q

Cushing’s Syndrome is also known as?

A

hyperadrenalcorticalism

84
Q

HCG is produced by the ? and begins to rise within ? after conception.

A

placenta

1-2 days

85
Q

Briefly explain the function of vasopressin.

A

stimulates reabsorption of water by the kidney tubules

86
Q

Where is the hormone epinephrine produced?

A

adrenal medulla

87
Q

Argentaffinomas produced elevated levels of what?

A

serotonin

88
Q

Briefly explain the function of oxytocin.

A

Site of action= smooth muscle; main functions to stimulate contractions of uterus during delivery and contractions of breast tissue cells to cause milk ejection

89
Q

What is the site of action for prolactin?

A

mammary glands

90
Q

In men, 2/3 of all 17-ketosteroids come from the ?

1/3 comes from the ?

A

adrenals

testes

91
Q

Name some conditions, other than pregnancy, where you may find increased HCG levels.

A

hydatidiform mole
choriocarcinoma
testicular tumors

92
Q

What foods should be excluded from the diet for at least two days prior to collecting a urine specimen for 5-HIAA?

A
bananas
avocados
pineapple
plums
walnuts
tomatoes
kiwi
eggplant
93
Q

How is most plasma thyroxine found?

A

bound to globulin

94
Q

What is the chief hormone excreted by the adrenal cortex?

A

cortisol

95
Q

The most potent and biologically active estrogen is ??

A

17-B-estradiol

96
Q

What is the action of progesterone?

A

preparation of uterus for ovum implantation

97
Q

What is the most potent of the biologically active androgens?

A

testosterone

98
Q

What is the parent substance in the biosynthesis of all adrenal cortical steroids?

A

cholesterol

99
Q

Of the thyroid iodide hormones, which is the most biologically active?

A

T3

100
Q

What hormone regulates the rate of thyroid hormone synthesis and secretion and where is it produced?

A

TSH

anterior pituitary

101
Q

Briefly explain the negative feedback mechanism in the relationship between cortisol and ACTH.

A

increase cortisol levels cause the hypthalamus and pituitary to decrease production of CRH and ACTH

decrease ACTH causes adrenal glands to decrease cortisol production