L5 - Cell injury and Cell death

Question 1

what are the two cellular adaptions a cell can make in response to external pressures?

Answer 1

hypertrophy

atrophy

Question 2

what is necrosis?

Answer 2

Severe cell swelling and rupture (not programmed)

Question 3

what is apoptosis?

Answer 3

Internally controlled cell death (programmed)

Question 4

what is oncosis?

Answer 4

Pre lethal changes preceding cell death

Question 5

what are causes of cell injury?

Answer 5

• Hypoxia 
• Physical agents
– Temperature, trauma, radiation 
• Chemical agents
– Drugs etc 
• Immunologic reactions 
• Infectious agents 
• Genetic derangements 
• Nutritional imbalances

Question 6

how does trauma cause cellular injury?

Answer 6

Mechanical disruption of tissue

Question 7

how does carbon monoxide inhalation cause cellular injury?

Answer 7

Prevents oxygen transport

Question 8

how does contact with strong acid cause cellular injury?

Answer 8

Coagulates tissue protein

Question 9

how does a paracetamol overdose cause cellular injury?

Answer 9

Metabolites bind to liver cell protein and lipoproteins

Question 10

how do bacterial infections cause cellular injury?

Answer 10

Toxins and enzymes

Question 11

how does ionising radiation cause cellular injury?

Answer 11

Damage to DNA

Question 12

a cell experiences swelling, pallor, hydropic change, vacuolar degeneration - what type of injury is this?

Answer 12

reversible

Question 13

what are the 3 types of. cellular injury?

Answer 13

reversible

irreversible

ischaemic/reperfusion

Question 14

a cell experiences Mitochondrial swelling, lysosomes swells, damage to membrane,
leakages of enzymes
- what type of injury is this?

Answer 14

irreversible

Question 15

a cell experiences New damage on reperfusion mediated by free oxygen radicals - what type of injury is this?

Answer 15

Ischaemic/Reperfusion injury

Question 16

features of a reversible cell injury?

Answer 16

• decreased generation of ATP
• loss of cell membrane integrity
• defects in protein synthesis and DNA damage

(cell shuts down to. concentrate on surviving)

Question 17

features of a irreversible cell injury?

Answer 17

• severe mitochondrial. changes
• extensive damage to plasma membranes
• swelling of lysosomes

Question 18

how does the degeneration of ATP in reversible cell injury, lead to cellular swelling?

Answer 18

• decreased ATP
• decreased activity of Na/K pump
• increased Na inside of cell
• water comes into cell (osmosis)
• cell swells

Question 19

in an irreversible cellular injury, membrane damage to lysosomes can cause what?

Answer 19

• leakage of lysosomal enzymes into cytosol

- enzymatic degradation of cell

Question 20

in an irreversible cellular injury, membrane damage to the cell membrane can cause what?

Answer 20

• increased Ca inside cell which activates proteases and other enzymes
• enzymatic degradation of cell

Question 21

in an irreversible cellular injury, membrane damage to mitochondria can cause what?

Answer 21

• cytochrome c. leakage

- activates caspaces which triggers apoptosis

Question 22

features of apoptosis?

Answer 22

• Programmed cell death
• Individual cell deletion
• Activated or prevented by many stimuli
• Increased apoptosis results in excessive cell loss e.g,
atrophy

Question 23

features of necrosis?

Answer 23

• Death of tissue following bioenergy failure and loss of plasma
membrane integrity
• Includes inflammation and repair

Question 24

what happens to the size of a cell in necrosis compared to apoptosis?

Answer 24

necrosis:

• cellular swelling
• many cells affected

apoptosis:

• cell shrinkage
• one cell affected

Question 25

what happens to the uptake of a cell in necrosis compared to apoptosis?

Answer 25

necrosis: - contents ingested by macrophages - significant inflammation apoptosis: - contents ingested by neighbouring cells - no inflammatory response

Question 26

what happens to the membrane of a cell in necrosis compared to apoptosis?

Answer 26

necrosis: - loss of membrane integrity - cell lysis occurs apoptosis: - membrane blebbing but integrity maintained - apoptotic bodies form.

Question 27

what happens to the organelles of a cell in necrosis compared to apoptosis?

Answer 27

necrosis: - organelle selling and lysosomal leakage - random degradation of DNA apoptosis: - mitochondria release pro-apoptotic proteins - chromatic condensation and non-random DNA degradation

Question 28

chromatic condensation is a feature of necrosis or apoptosis?

Answer 28

apoptosis

Question 29

cell lysis is a feature of necrosis or apoptosis?

Answer 29

necrosis

Question 30

organelle swelling is a feature of necrosis or apoptosis?

Answer 30

necrosis

Question 31

membrane blebbing is a feature of necrosis or apoptosis?

Answer 31

apoptosis

Question 32

an inflammatory response is a feature of necrosis or apoptosis?

Answer 32

necrosis

Question 33

what is autophagy?

Answer 33

cell dissembles itself/eats itself to provide energy to surrounding cells NB: normal natural response - no inflammatory response

Question 34

what are the 6 types of necrosis?

Answer 34

- coagulative - liquefactive - gangrenous - caseous - fat necrosis - fibrinoid necrosis

Question 35

what is the most common form of necrosis?

Answer 35

Coagulative Necrosis

Question 36

features of Coagulative Necrosis?

Answer 36

- cells retain their outlines | - architecture preserved but loss of proteins/enzymes and metabolic activity

Question 37

features of Liquefactive Necrosis?

Answer 37

``` • Seen in brain • Due to lack of substantial supporting stroma • Neural tissue may totally liquify ```

Question 38

what type of necrosis is seen in the brain?

Answer 38

Liquefactive Necrosis

Question 39

features of Gangrenous Necrosis?

Answer 39

``` • Putrefaction of the tissue • Cause is mostly infectious/ bacteria. • Appear black • Types – Wet gangrene – Dry gangrene – Gas gangrene ```

Question 40

what are the 3 types of gangrenous necrosis?

Answer 40

– Wet gangrene – Dry gangrene – Gas gangrene

Question 41

what is the main cause of Caseous Necrosis?

Answer 41

tuberculosis

Question 42

features of Caseous Necrosis?

Answer 42

``` • looks like cottage cheese • Tuberculosis is main cause • Structureless dead tissue • Amorphous pink material in centre with necrotic debri ```

Question 43

what are the two causes of fat necrosis?

Answer 43

enzymes trauma

Question 44

what two conditions is fibrinoid necrosis seen in?

Answer 44

malignant hypertension autoimmune diseases

Question 45

what type of necrosis is seen in autoimmune disease?

Answer 45

fibrinoid necrosis

Question 46

what type of necrosis is seen in malignant hypertension?

Answer 46

fibrinoid necrosis

Question 47

what is the most common site of Coagulative necrosis?

Answer 47

myocardium