Flashcards in Laboratory Medicine Deck (54)
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1
What are the 5 main electrolytes in body fluid?
Na+, Cl-, Mg2+, Ca2+, K+
2
What are the 5 functions of hepatocytes?
1) Drug and toxin metabolism
2) Aid digestion via biliary system
3) Protein synthesis and secretion
4) Energy storage (glycogen)
5) Transformation and clearance
3
How can acetaminophen cause liver necrosis?
Liver produces a toxic metabolite of APAP --> too much leads to necrosis
4
What is the main job of the liver?
Take insoluble compounds and make soluble for excretion
5
Pyridoxal phosphate (AKA Vitamin B6) plays a role in what types of reaction in the liver?
It is a coenzyme of all transamination reactions
6
What is the function of transaminases?
Transfer amine groups to allow for excretion
7
Is ALT or AST more specific for liver injury and why?
ALT is more specific because found in cytosol of liver - AST is found in both cytosol and mitochondria of liver along with many other organs
8
What four things cause elevated AST/ALT?
Viral hepatitis, fatty liver (sometimes), toxins (including medications), strenuous exercise
9
Alk phos tells you about the integrity of what?
Biliary tree
10
What are the components of total protein?
Albumin and globulin
11
Bilirubin is a ____________ of older blood cells
Degradation product
12
Bilirubin buildup can be toxic to which organ?
Brain
13
What are old red blood cells a source of?
Hemeproteins
14
What cell breaks down heme to bilirubin?
Macrophages
15
How is unconjugated bilirubin transported via blood to liver?
It is complexed with albumin
16
Once bilirubin is uptaken by the liver, what is it conjugated with?
Glucaronic acid
17
Where is conjugated bilirubin secreted into following the liver?
Into bile then into intestine
18
What happens to conjugated bilirubin in the intestine? (two steps)
Bacteria remove glnucaronic acid, then bilirubin is converted to urobilinogen
19
What are the three pathways urobilinogen may take from intestine?
1) Some reabsorbed from gut and enters portal blood where transported to kidney --> excreted in urine as yellow "urobilin"
2) participates in enterohepatic urobilinogen cycle
3) Oxidized by intestinal bacteria to brown stercoblin
20
In the kidney, urobilinogen is converted to what yellow substance?
Urobilin
21
If there is elevation in indirect bilirubin, would there be a defect in
a) pre hepatic
b) post hepatic
pathway?
a) pre hepatic
indirect = unconjugated
22
If there is elevation in direct bilirubin, would there be a defect in
a) pre hepatic
b) post hepatic
pathway?
b) post hepatic
direct = conjugated
23
Elevations in indirect bilirubin would NOT result from which of the following?
a) Increased production of non-conjugated bilirubin
b) Impaired conjugation of bilirubin
c) Increased hepatic uptake of bilirubin
c) is wrong
results from these 3:
1) increased production
2) impaired conjugation
3) impaired hepatic uptake
24
Would hemolysis result in
a) elevated indirect bilirubin
b) elevated direct bilirubin
a) elevated indirect
- more unconjugated bilirubin present
25
What is Kernicterus?
Elevation in indirect bilirubin in neonate and infants which leads to severe CNS deficiencies
26
Crippler/Najjar Syndrome and Gilbert's Dz both have what in common?
They are caused by problems with enzymatic action that lead to elevation of indirect bilirubin
27
What would cause accumulation of direct bilirubin?
a) Biliary obstruction
b) Biliary dysregulation
c) Increased secretion of conjugated bilirubin into bile
a) biliary obstruction
28
Which of the following diseases would NOT be indicated by elevated conjugated bilirubin?
a) Crigler/Najjar Syndrome
b) Gilbert's Disease
c) Hepatitis
d) Dubin-Johnson Syndrome
e) two of the above
E - A and B
29
Jaundice is the result of high amounts of ________ being deposited
Bilirubin
30
