Exam 2 Flashcards
Liver functions
carbohydrate metabolism, protein metabolism, lipid biosynthesis, storage of important substances, metabolic end-product excretion and detoxification, and bile pigment formation
Carbohydrate metabolism includes
gluconeogenesis and glycogen synthesis
Protein metabolism includes
most serum proteins synthesized in the liver, metabolic pool of amino acids
Lipid biosynthesis
excess carbs turned to fatty acid (palmitate), form ketone bodies, synthesis of VLDL and LDL, form bile acids
Storage of which important substances
iron, glycogen, amino acids, lipids and vitamins
Metabolic end-product excretion and detoxification
bind compound to protein, modify compound by hydroxylation and detoxification
Bile pigment formation
bilirubin and biliverdin
What is jaundice?
yellowish decolorization of skin and sclera from hyperbilirubinemia
Causes of jaundice
increase in bilirubin load on liver, defect in conjugation of bilirubin, defect in secretion of conjugated bilirubin, obstruction of the larger bile ducts
Classifications of jaundice
prehepatic, hepatic, posthepatic, neonatal, kernicterus
Prehepatic jaundice example
hemolytic anemia
hepatic jaundice example
defective conjugation or hepatitis
posthepatic jaundice example
impaired excretion of bilirubin to bile ducts
Neonatal jaundice example
physiological jaundice
Kernicterus
result of deposition of unconjugated bilirubin in nuclei of brain and nerve cells, causing cell destruction and encephalopathy
What is Hepatitis
inflammation of the liver
What causes hepatitis
viruses, bacteria, parasites, radiation, drugs, chemicals or toxins
Which hepatitis’ are caused by viruses?
A, B,C, D, E and CMV
What causes Hep. A?
Hep A virus, fecal-oral route
Hep. A virus
spherical particle containing DNA
Hep A symptoms
non-specific, abnormal ALT with or without jaundice, fecal shedding of the virus
Hep A antigen
not detectable in serum
IgM antigen for HAV
produced in initial phases
IgG antigen for HAV
produced in later phase and lasts years
How common is chronic carrier?
rare
Is there a vaccine for hep A?
Yes, but only available if over 2 years old and traveling or working in area with high transmission
How is Hep B transmitted?
parenteral, perinatal and sexual routes
Hep B virus structure
Central DNA core surrounded by a protein coat
Where is HBcAg?
The core
Where is HBsAg?
on surface
Where is Hep B virus found in the body?
All body fluids
Hep B clinical symptoms
abnormal liver functions tests, variable clinical courses with 2/3 asymptomatic and 1/3 have hepatitis-like syndrome
Recovery for Hep. B?
90% recovered in 6 months and develop antibody to HBsAg, 10% develop chronic hepatitis, cirrhosis, and carcinoma
Vaccine for Hep B?
Nationwide vaccine and immunoglobulin if needle-stick or born to an infected mother
What is tested for in all donated blood?
HBsAg
What is significant about HBsAg?
It is the first serological marker of acute Hep. B infection and can help identify infection before onset of infection
What after HBsAg disappears?
development of anti-HBsAg, common in most of the population
What is HBcAg?
the core antigen found in nuclei of hepatocytes during acute infection, not found in plasma
What develops first, anti-HBsAg or anti-HBcAg?
anti-HBsAg
Which Ig is shown for acute Hep. B infection?
IgM
Is HBcAg in serum?
Yes, it is associated with DNA dependant DNA polymerase so it is detectable in serum
HBeAg
E antigen correlates the number of infectious virus particles and the degree of infectivity of HBsAg-positive sera
What does HBeAg indicate?
unfavorable prognosis and chronic liver disease
Hep B viral DNA assay
nucleic acid hybridization or polymerase chain reactions, a more sensitive measurement of infectivity and disease prognosis, monitor the effectiveness of antiviral therapy in patients with chronic HBV
How is Hep. C transmitted?
the Hep C virus, caused by blood transfusions
What type of virus is Hep C?
an RNA virus
How is HCV detected?
Antibody can detect most infectious patients, but only at later stages, HCV RNA for early detection
HCV antibody
Not protective, can disappear years after infection
HCV symptoms
mild clinical course or asymptomatic
HCV progression
High progression to chronic hepatitis, cirrhosis and carcinoma