PATH 3610 EXAM STUDY GUIDE QUESTIONS WITH COMPLETE
SOLUTIONS
How are injuries classified? -- Answer ✔✔ Classified based on duration, severity, and
physiologic state.
1. adaptation (reversible - stimulus)
2. degeneration (reversible - injury)
3. cell death (irreversible - injury)
What 3 routes can adaptation take? -- Answer ✔✔ 1. Hypertrophy = increase in cell
size (occurs in all cells)
2. Hyperplasia = increase in cell number (occurs in labile and stable cells)
3. No response
Differentiate between permanent, stable, and labile cell types. -- Answer ✔✔ Permanent
cells = terminally differentiated cells that are incapable of dividing or divide at very low
rates.
,Stable cells = cells that exist in a resting state (Go) under normal conditions and can
divide in response to injury (adult stem cells).
Labile cells = continuously dividing cells (stem cells) that replace mature and terminally
differentiated cells.
*target for cytotoxic chemotherapy*
How is adaptation different from healing? -- Answer ✔✔ Adaption - responds to
stimulus by initiating hyperplasia or hypertrophy
Healing - responds to stimulus by initiating regeneration or by promoting scar tissue
formation
*in mammals regeneration occurs on a cellular or tissue level; organs and organ system
cannot regenerate*
What is regeneration? What is scarring? -- Answer ✔✔ Regeneration = occurs when
injured cells are replaced with cells of an identical or similar type.
Scarring = occurs when regeneration cannot occur due to damage to the extracellular
matrix. Injured cells are replaced with fibrous tissue.
What are the 4 stages of the cell cycle? How is the cell cycle regulated? -- Answer ✔✔
The cell cycle consists of:
1. Go (resting)/G1 (presynthetic phase)
, 2. S (DNA replication/synthesis)
3. G2 (pre-mitotic phase)
4. M (mitotic phase)
Regulated by:
1. +/- growth factors (EGF, TGF-β, IGF, FGF, VEGF)
2. cytokines
3. hormones
4. inherent characteristics of the cell (pluripotent vs. restricted differentiation pattern)
How is necrosis described macroscopically? -- Answer ✔✔ 1. Coagulative necrosis: cells
that retain characteristics of living cells (ex: steak)
2. Liquifactive necrosis: necrotic tissue that has been rendered liquid by enzymatic
action.
3. Caseous necrosis: necrotic tissue that has partially liquified or that was previously
liquified and has dehydrated.
4. Gangrenous necrosis: coagulative tissue is converted to liquid (wet), mummified (dry),
or produces gas due to bacterial action
How is necrosis described microscopically? -- Answer ✔✔ 1. Apoptosis: shrunken cells,
caused by caspase induced proteolysis.
SOLUTIONS
How are injuries classified? -- Answer ✔✔ Classified based on duration, severity, and
physiologic state.
1. adaptation (reversible - stimulus)
2. degeneration (reversible - injury)
3. cell death (irreversible - injury)
What 3 routes can adaptation take? -- Answer ✔✔ 1. Hypertrophy = increase in cell
size (occurs in all cells)
2. Hyperplasia = increase in cell number (occurs in labile and stable cells)
3. No response
Differentiate between permanent, stable, and labile cell types. -- Answer ✔✔ Permanent
cells = terminally differentiated cells that are incapable of dividing or divide at very low
rates.
,Stable cells = cells that exist in a resting state (Go) under normal conditions and can
divide in response to injury (adult stem cells).
Labile cells = continuously dividing cells (stem cells) that replace mature and terminally
differentiated cells.
*target for cytotoxic chemotherapy*
How is adaptation different from healing? -- Answer ✔✔ Adaption - responds to
stimulus by initiating hyperplasia or hypertrophy
Healing - responds to stimulus by initiating regeneration or by promoting scar tissue
formation
*in mammals regeneration occurs on a cellular or tissue level; organs and organ system
cannot regenerate*
What is regeneration? What is scarring? -- Answer ✔✔ Regeneration = occurs when
injured cells are replaced with cells of an identical or similar type.
Scarring = occurs when regeneration cannot occur due to damage to the extracellular
matrix. Injured cells are replaced with fibrous tissue.
What are the 4 stages of the cell cycle? How is the cell cycle regulated? -- Answer ✔✔
The cell cycle consists of:
1. Go (resting)/G1 (presynthetic phase)
, 2. S (DNA replication/synthesis)
3. G2 (pre-mitotic phase)
4. M (mitotic phase)
Regulated by:
1. +/- growth factors (EGF, TGF-β, IGF, FGF, VEGF)
2. cytokines
3. hormones
4. inherent characteristics of the cell (pluripotent vs. restricted differentiation pattern)
How is necrosis described macroscopically? -- Answer ✔✔ 1. Coagulative necrosis: cells
that retain characteristics of living cells (ex: steak)
2. Liquifactive necrosis: necrotic tissue that has been rendered liquid by enzymatic
action.
3. Caseous necrosis: necrotic tissue that has partially liquified or that was previously
liquified and has dehydrated.
4. Gangrenous necrosis: coagulative tissue is converted to liquid (wet), mummified (dry),
or produces gas due to bacterial action
How is necrosis described microscopically? -- Answer ✔✔ 1. Apoptosis: shrunken cells,
caused by caspase induced proteolysis.
