Lecture 2: Cell Injury, Adaptation, Death

Question 1

Etiology

Answer 1

Cause(s) of a condition

Question 2

Pathology

Answer 2

Study of suffering, disease

Question 3

Morphology

Answer 3

How pathology manifests cellularly; functional + clinical

Question 4

Types of adaptive cell responses

Answer 4

1. Hyperplasia
2. Hypertrophy
3. Atrophy
4. Metaplasia

Question 5

Atrophy examples

Answer 5

1. Physiologic:
   - Developmental regression
2. Pathologic:
   - Disuse, denervation, ischemia, aging, pressure, wasting

Question 6

Atrophy mechanisms

Answer 6

Lysosomes, ubiquitin proteasome paths, autophagic vacuoles, residual bodies

Question 7

Metaplasia

Answer 7

When epithelia switches cell types

Question 8

Cell injury

Answer 8

Occurs when adaptive response limits are exceeded
1. Reversible
2. Irreversible
3. Cell death
Threshold depends on cell state

Question 9

Types of cell death

Answer 9

• Necrosis (always patho.)
• Apoptosis (physio/patho)
• Necroptosis
• Pyroptosis
• Ferroptosis
  Subcellular alterations occur (IC accumulations, calcification, aging)

Question 10

Etiologies of cell injury

Answer 10

• Hypoxia (ischemia)
• Chemicals
• Infections
• Immune cells
• Genes
• Nutrition, etc.

Question 11

Common cell injury sites

Answer 11

• Mitochondria
• Cell membrane
• Nucleus

Question 12

Aspects of mitochondrial injury

Answer 12

Dysfunction leads to widespread stress/injury; ROS

Question 13

Necrosis

Answer 13

Gross, histologic cell death hallmark

Question 14

Apoptosis

Answer 14

Programmed cell death

Question 15

Necroptosis

Answer 15

RIPK3-programmed necrosis

Question 16

Pyroptosis

Answer 16

Activation of cytoplasmic danger-sensing inflammasome complex

Question 17

Anoikis

Answer 17

“Homelessness”
Apoptosis due to loss of ECM interactions

Question 18

Necrosis characteristics

Answer 18

Enzymatic digestion + leakage of cell contents; coagulative/liquefactive manifestations; swelling

Question 19

Apoptosis characteristics

Answer 19

• Single cell
• Nuclear fragmentation + cell shrinkage
• Non-inflammatory
• Membrane remains intact

Question 20

Apoptosis 2 main pathways

Answer 20

1. Intrinsic (mitochondria mediated)
2. Extrinsic (cell signal mediated; executioner caspases)

Question 21

Autophagy

Answer 21

Subcellular alterations in cell injury:
- Lysosomal catabolism
- Smooth ER induction (ribosome loss)
- Mitochondrial alteration
- Cytoskeletal abnormalities

Question 22

Mallory bodies

Answer 22

Formed in alcoholic liver cirrhosis; minute hyaline droplets

Question 23

Normal IC accumulations

Answer 23

Water, lipids, proteins

Question 24

Abnormal IC accumulations

Answer 24

• Exogenous e.g. iron, copper
• Endogenous e.g. complex carbs

Question 25

IC calcification

Answer 25

• Dystrophic (local, dying tissue)
• Metastatic (secondary to hypercalciemia)