1 - Cell Injury

Question 1

What are the 8 causes of cell injury?

Answer 1

1. Oxygen deprivation
2. Chemical agents
3. Infectious agents
4. Immunological reactions
5. Genetic defects
6. Nutritional imbalances
7. Physical agents
8. Ageing

Question 2

What does the cellular response to injuries depend on? (3 things)

Answer 2

1. Type of injury
2. Its duration
3. The severity

Question 3

What do the consequences of a cell injury depend on? (4 things)

Answer 3

1. Type of cell
2. Its status
3. Its adaptability
4. Its genetic makeup

Question 4

Which 4 intracellular systems are particularly vulnerable?

Answer 4

1. Cell membrane integrity
2. ATP generation
3. Protein synthesis
4. Integrity of genetic apparatus

Question 5

What are the mechanisms of cell injury?

Answer 5

The structural and biochemical components of a cell are so integrally related that multiple secondary effects rapidly occur.

1. Cellular function is lost
2. Then cell death occurs
3. Then morphological changes are seen.

Question 6

What are the 6 cellular adaptations to injury?

Answer 6

1. Atrophy
2. Hypertrophy
3. Hyperplasia
4. Metaplasia
5. Dysplasia
6. Apoptosis

Question 7

What is atrophy?

Answer 7

Shrinkage in the size of the cell (or organ) by the loss of cell substance.

Question 8

What is hypertrophy?

Answer 8

Increase in the size of cells and consequently an increase in the size of the organ
Can be physiological or pathological

Question 9

What causes hypertrophy?

Answer 9

• Increased functional demand

- Specific hormonal stimulation

Question 10

What is hyperplasia?

Answer 10

An increase in the number of cells in an organ.

Can be physiological or pathological

Question 11

What is physiological hyperplasia?

Answer 11

It is hormonal or compensatory

Question 12

What is pathological hyperplasia?

Answer 12

Due to excessive hormonal or growth factor stimulation

Question 13

What is metaplasia?

Answer 13

A reversible change in which one adult cell type is replaced by another

Question 14

What is dysplasia?

Answer 14

Precancerous cells which show the genetic and cytological features or malignancy but not invading the underlying tissue

Question 15

What light microscope changes would you see for REVERSIBLE injury due to dysplasia?

Answer 15

• Fatty change

- Cellular swelling

Question 16

What light microscope changes would you see for IRREVERSIBLE injury due to dysplasia?

Answer 16

• Coagulative necrosis
• Liquefactive necrosis
• Caseous necrosis
• Fat Necrosis

Question 17

What is apoptosis?

Answer 17

The death of cells which occurs as a normal and controlled part of an organism’s growth or development.

Question 18

What are the 5 causes of apoptosis?

Answer 18

1. Embryogenesis
2. Deletion of auto-reactive T cells in the thymus
3. Hormone-dependent physiological involution
4. Cell deletion in proliferating populations
5. A variety of mild injurious stimuli that cause irreparable DNA damage that triggers cell suicide pathways

Question 19

What is necrosis?

Answer 19

The death of cells in an organ or tissue due to disease, injury, or failure of the blood supply.

Question 20

What are the 3 difference between apoptosis and necrosis?

Answer 20

1. Apoptosis may be physiological
2. Apoptosis is an active energy dependent process
3. Not associated with inflammation