Lec 1

Question 1

List four pathogenesis of a cell injury:
1)
2)
3)
4)

Answer 1

Loss of Ca homeostasis.
Reduced ATP/synthesis.
Free radicals.
Disrupted membrane permeability.

Question 2

When can cell injury be first viewed, and does this mean reversible or irreversible is apparent for the cell?

Answer 2

The cell injury can be first seen by nuclear and cytoplasmic changes.
The cell injury will be irreversible

Question 3

What mechanism does hypoxia lead to, for cell dead to occur?

Answer 3

Decrease in O2 consumption which in turn lowers ATP production. This means the cell metabolite process decreases and waste accumulation will occur in the cell

Question 4

What is hypoxaemia?

Answer 4

Oxygen absorbing problems are apparent in the haemoglobin.

Question 5

Lower in ATP will cause?
1)
2)
3)

Answer 5

Nuclear clumping
Protein synthesis decrease
ER swelling

Question 6

Membrane damage are from what two main causes, in an injured cell?

Answer 6

Increase in phospholipid enzyme activity.

Cytoskeletal damage to the cell

Question 7

Heat shock gene are for what purpose in cell injury?

Answer 7

They help the cell survive a stressful environment, by cleaning up damaged proteins and produce more protein chaperone for the protein function to still occur during injury.

Question 8

What is a mechanism which Ca ion influx will occur?

Answer 8

Trauma -> loss to regulate cell environment -> Ca influx -> over activation of enzymes -> membrane damage, nuclear damage and decrease ATP

Question 9

Give 3 necrotic specific cell characteristics:

Answer 9

Mitochondria, ER swelling
Membrane blebbing
Adjacent influence inflammation

Question 10

Give 3 main apoptotic specific cell injury characteristics:

Answer 10

Condensation of chromatin
Reduction in cell size
Cause mainly by physiological injury

Question 11

What are the 4 type of necrosis?

Answer 11

Caseous necrosis
Coagulative necrosis (most common)
Liquefactive necrosis (neutrophil infiltration, in brain)
Infarction (red or white)

Question 12

Apoptosis has an extrinsic and intrinsic pathways. Briefly explain the differences between the two:

Answer 12

Intrinsic: Cell injury occurs -> BLC2 sensors -> Bax activates -> cytochrome c produced from mitochondria -> apoptosis occurs

Extrinsic: FasL from T cell is presented -> Fas or TNF receptor activated -> initiator caspases form -> executioner caspases activate -> apoptosis