Cell Pathology 4 - Cell Injury

Question 1

What are the two types of cell injury?

Answer 1

• Lethal produces cell death

- Sublethal produces injury not amounting to cell death, which may be reversible or progress to cell death

Question 2

List the causes of cell injury

Answer 2

• Oxygen deprivation
• Chemical agents
• Infectious agents
• Immunological reactions
• Genetic defects
• Nutritional imbalances
• Physical agents
• Aging

Question 3

What does the cellular response to injury depend on?

Answer 3

The type of injury, duration and its severity.

Question 4

What do the consequences of an injurious stimuli depend on?

Answer 4

Depends on the cell type and on its status

Question 5

Which intracellular systems are particularly vulnerable to cell injury?

Answer 5

• Cell membrane integrity
• ATP generation
• Protein synthesis
• The integrity of genetic apparatus

Question 6

What is atrophy?

Answer 6

Shrinking of a cell

Question 7

Give an example of atrophy

Answer 7

Dementia

Question 8

When does muscle atrophy occur?

Answer 8

It occurs secondary to denervation

Question 9

What is hypertrophy?

Answer 9

Increase in the size of cell and consequence organs increase in size.

Question 10

What causes hypertrophy?

Answer 10

Increased cellular demand or hormonal triggers

Question 11

Give an example of physiological hypertrophy.

Answer 11

The uterus swells during pregnancy

Question 12

Give an example of pathological hypertrophy.

Answer 12

Myocytes swell due to injury causing cell death, or due to increased load.

Question 13

What is hyperplasia?

Answer 13

An increase in the number of cells in the organ

Question 14

What causes hyperplasia?

Answer 14

• Physiological is caused by hormones/may be compensatory

- Pathological hyperplasia is due to excessive hormonal or growth factor production

Question 15

Give an example of physiological hyperplasia.

Answer 15

Proliferative endometrium (increase in thickness of the lining of the uterus)

Question 16

Give an example of pathological hyperplasia

Answer 16

Carcinoma

Question 17

What is metaplasia?

Answer 17

A reversible change where one cell type is replaced with another

Question 18

Give an example of physiological metaplasia

Answer 18

The lining of the cervix - columnar to squamous and the reverse during puberty.

Question 19

Give an example of pathological metaplasia

Answer 19

Barrett’s oesophagus - acidosis causes the oesophagus wall to become columnar. Can be reversed.

Question 20

What is dysplasia?

Answer 20

Precancerous cells which show the genetic and cytological features of malignancy but don’t invade underlying tissue.

Question 21

What may dysplasia be associated with?

Answer 21

Barrets oesophagus

Question 22

What are the light microscopic changes associated with reversible injury?

Answer 22

Fatty change and cellular swelling

Question 23

What is necrosis?

Answer 23

Congruent cell death associated with inflammation

Question 24

What are the types of necrosis?

Answer 24

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

Question 25

What is coagulative necrosis?

Answer 25

Where the cells are dead but can still be seen and recognised.

Question 26

What is confluent cell death?

Answer 26

Death of many cells that are close together.

Question 27

What is liquefactive necrosis?

Answer 27

Occurs in the brain - the absence of cells but presence of liquids.

Question 28

What is caseous necrosis?

Answer 28

Looks like cheese - creamy and oozes out when cut

Question 29

What is fat necrosis?

Answer 29

This is where lipase is released and this breaks down triglycerides to fatty acids. The fatty acids bind with calcium to form salts, which deposit to form fat necrosis

Question 30

Give an example of coagulative necrosis

Answer 30

Myocardial infarction - you can recognise the cells

Question 31

Give an example of a caseous infarct

Answer 31

Pulmonary TB

Question 32

Give an example of fat necrosis

Answer 32

Acute pancreatitis

Question 33

What are the possible causes of apoptosis?

Answer 33

- Embryogenesis - Deletion if autoreactive T cells in the thymus - Hormone dependent involution - Mild injurious stimuli that damage DNA

Question 34

What are the differences between apoptosis and necrosis?

Answer 34

- Necrosis is leakage of cellular contents, while apoptosis involves formation of apoptotic bodies which are phagocytosed - Apoptosis can be physiological - Apoptosis requires energy - Apoptosis is NOT associated with inflammation

Question 35

What is necroptosis?

Answer 35

- Programmed cell death associated with inflammation | - Has many causes, such as viral infections