Growth Adaptations, Cellular Injury and Cell Death

Question 1

Barret’s Esophagus

Answer 1

Metaplasia

- squamous -> columnar/non-ciliated/with goblet cells

Question 2

Keratomalacia

Answer 2

Metaplasia

- resulting from vitamin A deficiency

Question 3

Budd-Chiari Syndrome

Answer 3

• thrombosis of the hepatic vein; blood can’t flow through the liver; infarction of liver parenchyma (ischemia)
• common causes:
  1. polycythemia vera; blood is thick and viscous leads to thrombosis
  2. lupus anticoagulant; hypercoaguable state in the patient

Question 4

CO poisoning

Answer 4

• hypoxia due to decreased oxygen carrying capacity of the blood
• PaO2 normal, SaO2 decreased
• early sign of exposure: headache
• cherry red skin
• common causes: smoke from fire, exhaust from cars, gas heaters

Question 5

Methemoglobinemia

Answer 5

• hypoxia due to decreased oxygen carrying capacity of the blood
• normally, Fe2+ binds O2 -> iron in heme oxidized to Fe3+, which can’t bind O2
• PaO2 normal, SaO2 decreased
• common causes: oxidant stress (i.e. sulfa and nitrate drugs), and seen in newborns (b/c babies don’t have necessary enzymes to deal with reactive oxidative substances)
• cyanosis
• chocolate-coloured blood
• treatment: IV methylene blue (reduces iron back to Fe2+ state)