Cell Injury & Cell Death

Question 1

What is degree of injury dependant on

Answer 1

Type of injury
Severity of injury
Duration of injury
Type of tissue

Question 2

Environmental causes of cell injury

Answer 2

Hypoxia
Toxins
Immune mediated
Physical agents
Infection
Nutritional

Question 3

Non-environmental causes of cell injury

Answer 3

Genetic
Ageing

Question 4

Causes of hypoxia

Answer 4

Hypoxaemic hypoxia
Anaemia hypoxia
Ischaemic hypoxia
Histiotoxic hypoxia

Question 5

Hypoxaemic hypoxia

Answer 5

Arterial content of oxygen is low

Question 6

Anaemia hypoxia

Answer 6

Decreased ability of haemoglobin to carry oxygen

Question 7

Ischaemic hypoxia

Answer 7

Interruption to blood supply

Question 8

Histiotoxic hypoxia

Answer 8

Inability to utilise oxygen due to disabled oxidative phosphorylation enzymes

Question 9

Types of immune mediated cause of cell injury

Answer 9

Hypersensitivity reactions
Autoimmune reactions

Question 10

What are the hypersensitivity reactions
Give an example of this

Answer 10

Injury secondary to excessive immune reaction to a ‘non-self’ antigens
e.g.) anaphylaxis in peanut allergy

Question 11

What are the autoimmune reactions
Give an example of this

Answer 11

Immune system overreacts to a self antigen causing tissue damage
e.g.) Grave’s disease

Question 12

List the mechanisms of cell injury

Answer 12

1. Depletion of ATP
2. Direct mitochondrial damage
3. Direct membrane damage
4. Disruption to calcium homeostasis
5. Oxidative stress (free radicals)
6. Direct damage to DNA & proteins

Question 13

Describe how ATP depletion can lead to cell injury (briefly)

Answer 13

1.Cell deprived of oxygen
2. Reduction in oxidative phosphorylation
3.Mitochondrial ATP production stops

Question 14

What effects will cellular reduction in ATP have

Answer 14

Anaerobic glycolysis
Affect energy depended to Na+/K+ pump
Ribosomes detach from ER

Question 15

What can free radicals damage

Question 16

Pathways for removing free radicals

Answer 16

Anti-oxidants
Transport proteins
Enzymes

Question 17

Describe heat shock proteins

Answer 17

Repairs and re-fold damaged proteins
Label them for degradation

Question 18

Example of heat shock proteins

Answer 18

Ubiquitin

Question 19

Types of cell death

Answer 19

Apoptosis
Necrosis
Oncosis

Question 20

Define oncosis

Answer 20

Cell death with swelling

Question 21

Define apoptosis

Answer 21

Cell death with shrinkage

Question 22

Define necrosis

Answer 22

In a living organism the morphological changes that occur after a cell has been dead some time

Question 23

What are the characteristic nuclear changes in necrosis

Answer 23

Pyknosis (shrinkage)
Karyorrhexis (fragmentation)
Karyolysis (dissolution)

Question 24

Subtypes of necrosis

Answer 24

Coagulation
Liquefactive
Caseous
Fat necrosis
Fibrinoid necrosis

Question 25

Two main types of necrosis

Answer 25

Coagulative
Liquifactive (colliquitive)

Question 26

Coagulative necrosis

Question 27

Gangrene

Answer 27

Necrosis visible to the naked eye

Question 28

Infarction

Answer 28

Necrosis caused by reduction in arterial blood flow
(can result in gangrene)

Question 29

Complications of infarction depends on

Answer 29

Alternative blood supply
Speed of Ischaemia
Tissue involved
Oxygen content of the blood

Question 30

Which enzymes/proteins are found in high serum conc. in hepatitis

Answer 30

Hepatitis: AlT, LDH, Bilirubin
Acute pancreatitis: Amylase, Lipase
Myocardial infarction: Troponin, Creatine kinase, Myoglobin, LDH