Cellular Adaptations and Cellular Damage

Question 1

What is cellular adaptation? Is it reversible?

Answer 1

The ability of cells to respond to various types of stimuli and adverse environmental changes. Stimuli may arise under physiological or pathological conditions. Adaptations are reversible.

Question 2

Cellular adaptation reflects an attempt by the cells to do what?

Answer 2

Preserve cell vitality

Question 3

In terms of proliferative capacity, what are the 3 classes of cells and how often do they divide?

Answer 3

1. Labile cells - continuously dividing in adult life.
2. Stable cells - Infrequent divisions but rapid division if needed (‘conditional renewal cells’).
3. Permanent cells - Never divide in adult life.

Question 4

What are the 4 main types of cellular adaptation?

Answer 4

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

Question 5

What is hyperplasia?

Answer 5

An increase in the number of cells within a tissue.

Question 6

What is hypertrophy?

Answer 6

An increase in cell size.

Question 7

In which kind of cells is hypertrophy most common?

Answer 7

It can occur in any cells, but is most common when permanent cells experience increased demands.

Question 8

What is atrophy?

Answer 8

Shrinkage in cell size by loss of cell substance.

Question 9

How do cells get rid of their organelles when undergoing atrophy?

Answer 9

Autophagy

Question 10

List some causes of cell atrophy.

Answer 10

Reduced workload
Reduced blood supply
Loss of nerve supply
Inadequate nutrition
Ageing

Question 11

What is metaplasia?

Answer 11

A reversible change from one adult cell type to another adult cell type.

Question 12

What are the 2 main types of abnormal cell growth?

Answer 12

1. Neoplasia

2. Dysplasia

Question 13

What is dysplasia?

Answer 13

The growth of abnormal cells in a tissue or organ.

Question 14

What is neoplasia?

Answer 14

The abnormal growth of cells which persists after the initiating stimulus has been removed.

Question 15

List 6 broad causes of cell injury and death.

Answer 15

1. Oxygen deprivation
2. Physical agents
3. Chemicals and drugs
4. Infectious agents
5. Immune reactions
6. Nutritional imbalances

Question 16

What are the 3 main ways in which chemicals can cause cell injury?

Answer 16

1. Perturbation of the osmotic environment of the cell.
2. Disruption of biochemical reactions e.g. if ATP levels drop to below critical levels, affected cells will die.
3. Compromising the integrity of the cell membrane.

Question 17

Which 3 main immune mediated causes of damage to cells?

Answer 17

1. The immune response it excessive
2. Inappropriately targeted e.g. autoimmune
3. Insufficient e.g. immunodeficient states.

Question 18

What are the types of cell death?

Answer 18

1. Apoptosis

2. Necrosis

Question 19

List 6 types of necrosis.

Answer 19

1. Coagulative
2. Liquefactive
3. Caseous
4. Gangrenous
5. Fat
6. Fibrinoid

Question 20

What type of cell death can be seen in tuberculosis?

Answer 20

Caseous necrosis.