CSIM 1.2 Introduction to Disease: Cell Injury

Question 1

Name the four cell areas vulnerable to injury?

Answer 1

Cell membrane
Areas of protein synthesis
Mitochondria (energy production specifically important in dividing cells)
Nucleus

Question 2

Name the seven causes of cell injury?

Answer 2

Metabolite deprivation (hypoxia/ischaemia)
Physical agents (heat/cold/pressure)
Chemical agents (direct - ricin//in-direct - paracetamol)
Infection
Hypersensitivity
Genetics (sickle-cell anaemia)
Nutritional imbalances

Question 3

Describe coagulative necrosis?

Answer 3

Protein denaturation caused by infarction/ischaemia

Collagen is resistant to this and therefore cell scaffolding remains

Question 4

Describe liquifaction necrosis?

Answer 4

Enzymatic digestion which may involve puss
Main type of necrosis in the brain
Caused by infection (bacterial)

Question 5

Describe caseous necrosis?

Answer 5

Cheese-like appearance
Coagulative and granular debris
Caused by T.B and syphilis

Question 6

Describe fat necrosis?

Answer 6

Trauma - especially seen in breast tissue

Lipases - especially seen in pancreas

Question 7

Describe fibrinoid necrosis?

Answer 7

Blood vessel wall necrosis
Fibrin replaces part of the vessel wall
Caused by vasculitis and malignant hypertension

Question 8

Describe gangrene necrosis?

Answer 8

A mixture of liquefaction and putrefaction

Caused by clostridium perfinges

Question 9

Name the two types of gangrene necrosis and state where each may be likely to occur?

Answer 9

Wet - bowel infaction via infection

Dry - seen on limbs

Question 10

Describe the two types of calcification that may occur following necrosis?

Answer 10

Dystrophic calcification - seen in dead tissue with normal plasma calcium levels
Metastatic calcification - seen in normal tissue with high plasma calcium levels (occurs after bone destruction)

Question 11

Name the four micro-cellular stages involved during apoptosis?

Answer 11

Signalling
Control and integration phase
Common executioner phase
Removal of dead cells

Question 12

In apoptosis how does micro-cellular signalling occur?

Answer 12

Cytoxic T-cells release perforin (makes a hole in the cell) and Granzyme B
Cell DNA damage causes the release of p53 which arrests the cell cycle

Question 13

In apoptosis how does micro-cellular control and integration occur?

Answer 13

BCL-2 family (pro and anti apoptotic types)

Initiator capases also play an essential role

Question 14

In apoptosis how does micro-cellular common execution occur?

Answer 14

Capases cause the execution via activation of proteases and endonucleases
Cytoskeletal cleavage causes blebbing and DNA is evenly cut up

Question 15

Between apoptosis and necrosis what is the difference in the extent?

Answer 15

Apoptosis - single cell death

Necrosis - groups of cell death

Question 16

Between apoptosis and necrosis what is the difference in energy requirement?

Answer 16

Apoptosis - requires energy for the control process

Necrosis - n/a

Question 17

Between apoptosis and necrosis what is the difference between membrane integrity?

Answer 17

Apoptosis - membrane of cell maintained

Necrosis - membrane of cell lost

Question 18

Between apoptosis and necrosis what is the difference between inflammation?

Answer 18

Apoptosis - none

Necrosis - lots of inflammation

Question 19

Between apoptosis and necrosis what is the difference between the fate of dead cells?

Answer 19

Apoptosis - neighbours

Necrosis - macrophages and neutrophils