L5 Cellular Injury and Adaptation

Question 1

Examples of causes of injury (4)

Answer 1

lack of oxygen
physical
chemical
infectious agents

Question 2

What are some biochemical mechanisms of injury? (5)

Answer 2

ATP depletion
oxygen derived free radicals
intracellular calcium and loss of homeostasis
defects in membrane permeability
irreversible mitochondrial damage

Question 3

What are the primary targets of cellular injury (4)

Answer 3

mitochondria (hypoxia)
cell membrane (oxy radicals)
cytoskeleton (immune mediated)
cellular DNA (oxy radicals)

Question 4

Causes of reversible cell injury (6)

Answer 4

oxygen and ATP levels drop
anaerobic glycolysis 
lactic acid and pH drop
Na pump failure
Na and water in cytoplasm (swelling)
swelling and dilation of endoplasmic reticulum (protein synthesis inhibited)

Question 5

Cause of irreversible cell damage

Answer 5

calcium activating enzymes such as phospholipases, proteases, ATPases, endonucleases which lead to structural damage

Question 6

What three things can happen to a cell nucleus

Answer 6

pyknosis - smaller, condensed, stained with haemotoxylin
karyorrnexis - fragmentation of nucelus
karyolysis - complete break down

Question 7

Examples of free radicals (3)

Answer 7

superoxide anion
hydroxyl radical
hydrogen peroxide

Question 8

How can free radicals cause injury (3)

Answer 8

peroxidation of lipid membranes
attack thiol groups on proteins (maintain 3D structure)breakdown of DNA
NADPH depletion of mitochondria, leads to calcium in cytosol

Question 9

Protective mechanisms against free radicals (4)

Answer 9

antioxidants
glutathione peroxidase
superoxide dismutase
catalase

Question 10

Morphology of necrosis (6)

Answer 10

swelling
nuclear and cytoplasmic degradation
coagulative
liquefactive
caseous
fatty

Question 11

What can cause fatty liver

Answer 11

alcohol, obesity, toxins, protein malnutrition, diabets