Cell injury and fate

Question 1

The cycle?

Answer 1

Normal cell (homeostasis) –(injurious stimulus)–> cell injury to cell death

normal cell (homeostasis) --(stress, increased demand)--> adaptation
--> inability to adapt --> cell injury to cell death

Question 2

What are the causes of cell injury?

Answer 2

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

Question 3

What does the cellular response to injurious stimuli depends on?

Answer 3

• the type of injury
• its duration
• its severity

Question 4

What does the consequence of an injurious stimulus depend on?

Answer 4

• type of cell

- its status

Question 5

What are the four intracellular systems that are particularly vulnerable?

Answer 5

• cell membrane integrity
• ATP generation,
• protein synthesis
• the integrity of the genetic apparatus

Question 6

Why do multiple secondary effects rapidly occur?

Answer 6

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

Question 7

Cellular function is lost before cell death occurs..

Answer 7

which in turn occurs before the morphological changes are seen
(cardiac- will stop trying to contract whilst alive- if the injury goes on further, they will die)
- just bc a cell looks normal it doesnt mean its functional

Question 8

What is lethal cell injury?

Answer 8

capable of causing death

Question 9

What is sublethal cell injury?

Answer 9

consequence of exposure to a chemical or physical process that damages but does not kill a cell

Question 10

What is morphology?

Answer 10

structural histological changes

Question 11

What is atrophy?

Answer 11

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

Question 12

What is hypertrophy?

Answer 12

• Increase in the size of cells and consequently an increase in the size of the organ
• Can be physiological (process that occurs in normal healthy people) or pathological (part of the disease process)

Question 13

What is the cause of hypertrophy?

Answer 13

• increased functional demand

- specific hormonal stimulation

Question 14

examples of hypertrophy

Answer 14

• uterus during pregnancy (physiological)
• muscle fibres( valve abnormality or hypertension) - pathological
  athletes (physiological)

Question 15

What is hyperplasia?

Answer 15

• increase in the number of cells in an organ

- physiological or pathological

Question 16

What can physiological hyperplasia be?

Answer 16

hormonal or compensatory

Question 17

What can pathological hyperplasia be due to?

Answer 17

excessive hormonal or growth factor stimulation.

Question 18

What is an example of hyperplasia?

Answer 18

• menstruation and regrowth of cell wall (physiological)

- cancer (pathological)

Question 19

What is metaplasia?

Answer 19

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

Question 20

Examples of metaplasia?

Answer 20

• pregnancy – cervix expands + columnar epithelium of the endocervix which is normally in the canal, becomes visible outside (due to the acidic pH of the vagina the columnar epithelium changes from being columnar into squamous– physiological
• barretts oesophagus( acid reflux into intestine- squamous epithelium becomes columnar)

Question 21

What is dysplasia?

Answer 21

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

Question 22

What is dysplasia associated?

Answer 22

with Barretts oesophagus

Question 23

What reversible injuries is the light microscopic changes associated with?

Answer 23

Fatty change
Cellular swelling
ballooning degeneration
- degenerative changes

Question 24

What are degenerative changes?

Answer 24

changes associated with cell and tissue damage

Question 25

What is necrosis?

Answer 25

Confluent cell death associated with inflammation

Question 26

What irreversible injuries is the light microscopic changes associated with?

Answer 26

Coagulative necrosis Liquefactive necrosis Caseous necrosis Fat Necrosis

Question 27

What is coagulative necrosis?

Answer 27

the structure becomes fixed, in the same way if you fry an egg (muscle fibres)

Question 28

What is liquefactive necrosis?

Answer 28

the tissue becomes liquefied (old cerebral infarct)

Question 29

What is Caseous necrosis?

Answer 29

cheesy oozy + structureless (tuberculosis)

Question 30

What is fat necrosis?

Answer 30

in acute pancreatitis( enzymes become active in pancreas and not duodenum)

Question 31

What is apoptosis?

Answer 31

programmed cell death/ death of individual cells theres confluence, sheets of dead cells and a marked inflammatory reaction around

Question 32

What separates apoptosis from necrosis?

Answer 32

confluence and inflammatory reaction

Question 33

The apoptotic cells are swallowed up by macrophages

Answer 33

in a very neat manner

Question 34

Necrosis

Answer 34

a lot of inflammation and inflammatory response

Question 35

What are the causes of apoptosis?

Answer 35

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

Question 36

What is mild injury?

Answer 36

causes but mild enough to cause irreparable DNA damage, may trigger this kind of suicide pathway by which the cells kill themselves It cannot be repaired. And because the cells does not want to pass this kind of damage DNA onto the next generation.

Question 37

If some errors remain, and particularly if there's some additional injury,

Answer 37

the cell can no longer repair itself and therefore it will go down and die by apoptotic pathway.

Question 38

What is required for apoptosis?

Answer 38

ATP so these cells can maintain cell membrane integrity | package all the organelles and break into little fragments, which can then taken up by the macrophages.

Question 39

What is necroptosis?

Answer 39

cell death, programmed cell death associated with inflammation many causes eg. viral infection