Chapter 1

Question 1

Methods for chemical injury?

Answer 1

1. Direct (e.g. binding directly to cell components)

2. Indirect (e.g. conversion to toxic metabolites, esp. by p450 oxidases in smooth ER of liver)

Question 2

Physiologic settings for apoptosis

Answer 2

1. Programmed death of cells during embryogenesis.
2. Involution of hormone-dependent tissues when hormones withdrawn
3. Cell loss in proliferating populations (e.g. immature leukocytes not of use).
4. Destruction of potentially harmful self-reactive lymphocytes
5. Death of cells that have served their purpose (e.g. inflammatory cells)

Question 3

Pathologic settings for apoptosis

Answer 3

1. DNA damage (e.g. radiation, hypoxia)
2. Accumulation of misfolded proteins.
3. Cell death in some infections (e.g. viruses)
4. Pathologic atrophy in some organs after duct obstruction (e.g. pancreas, parotid)

Question 4

Biochemical features of apoptosis

Answer 4

1. ) Activation of caspases
2. ) DNA and protein breakdown
3. ) Membrane configuration changes to promote recognition by phagocytes