cell injury

Question 1

cell injury can be reversible or irreversible, what are the characteristics of reversible cell injury?

Answer 1

• cells adapt to change sin environment

- return to normal once stimuli removed

Question 2

cell injury can be reversible or irreversible, what are the characteristics of irreversible cell injury?

Answer 2

• permanent

- cell death

Question 3

which factors determine whether cell injury is reversible or irreversible?

Answer 3

• cell type
• duration
• severity
• susceptibility/adaptabilty of cell (nutritional status)

Question 4

give examples of some causes of cell injury

Answer 4

• hypoxia
• physical agents
• chemicals
• infection
• immunological reaction

Question 5

what is hypoxia?

Answer 5

decreased oxygen

Question 6

which conditions may hypoxia cause?

Answer 6

• anaemia

- reparatory failure

Question 7

what effect does hypoxia have on cell respiration?

Answer 7

decreased ATP as cell cannot aerobically respire, cell still capable of anaerobic respiration

Question 8

what is ischaemia?

Answer 8

decreased blood flow to tissues

Question 9

what is more severe, hypoxia or ischaemia?

Answer 9

ischaemia

Question 10

give an example of a condition caused as a result of ischaemia

Answer 10

atherosclerosis

Question 11

what effect does iscghaemia have on cell respiration?

Answer 11

no aerobic or anaerobic respiration

Question 12

give examples of physical agents which may cause cell injury

Answer 12

• mechanical trauma (affect cell structure)
• temp (affect proteins, chemical reaction)
• ionising radiation (DNA damage)
• electric shock

Question 13

give examples of infectious agents which may cause cell injury

Answer 13

bacteria, fungi, parasite, virus, proton

Question 14

give examples of chemical agents which may cause cell injury

Answer 14

• simple chemical (i.e glucose in excess may cause osmotic imbalance)
• poison
• asbestos (inflammation)
• alcohol, smoking, recreational drugs

Question 15

reversible injury may cause disruption to ?

Answer 15

• respiration
• plasma membrane integrity
• protein synthesis
• DNA maintenance

Question 16

what morphological changes may occur as a result of reversible cell injury?

Answer 16

• cloudy swelling

- fatty changes

Question 17

what happens to a cloudy swollen cell?

Answer 17

• incapable of maintaining ionic and fluid homeostasis
• failure of energy dependant ion pumps leading to influx of Na and water
• build up of intracellular metabolites

Question 18

how does fatty change occur in an injured cell ?

Answer 18

accumulation of lipid vacuoles in cytoplasm by disruption to fatty acid metabolism

Question 19

what type of cell injury causes fatty changes?

Answer 19

toxic and hypoxic

Question 20

what systemic effect does fatty changes to a cell have?

Answer 20

enlarged and pale liver

Question 21

what is the definition of necrosis?

Answer 21

cell death due to pathology

Question 22

what happens during necrosis?

Answer 22

• intracellular protein denaturation & lysosomal digestion of cell
• cell membrane disputed so contents leak

Question 23

which cell death, apoptosis or necrosis, always involves an inflammatory response?

Answer 23

necrosis

Question 24

which cell death, apoptosis or necrosis, never involves an inflammatory response?

Answer 24

apoptosis

Question 25

what microscopical changes occur as a result of necrosis?

Answer 25

- pyknosis (nucleus shrinks) | - karyorrhexis (nucleus fragments)

Question 26

if necrotic remains are not removed, what occurs?

Answer 26

Ca salts deposited in necrotic tissue

Question 27

which cell death, apoptosis or necrosis, requires energy?

Answer 27

apoptosis

Question 28

what is apoptosis?

Answer 28

programmed cell death

Question 29

what are the pathological triggers of apoptosis?

Answer 29

- hypoxia/ischaemia - viral infection - DNA damage (unrepeatable p53) - caspases trigger it

Question 30

give some physiological roles of apoptosis

Answer 30

- deletion of self reactive lymphocytes in thymus - maintain constant number of cells - delete inflammatory cells after inflammation

Question 31

describe some morphological feature of apoptosis

Answer 31

- cell shrinkage - chromatin condenses - membrane intact

Question 32

which cell death, apoptosis or necrosis results in enlarged cell size?

Answer 32

necrosis

Question 33

which cell death, apoptosis or necrosis results in reduced cell size?

Answer 33

apoptosis

Question 34

which cell death, apoptosis or necrosis results in disrupted membrane?

Answer 34

necrosis

Question 35

which cell death, apoptosis or necrosis results in intact contents?

Answer 35

apoptosis

Question 36

which cell death, apoptosis or necrosis has a physiological role?

Answer 36

apoptosis

Question 37

what is amyloid?

Answer 37

fibrillar protein that is deposited in the liver, kidneys, spleen, or other tissues due to pathology

Question 38

name the 3 types of amyloid protein

Answer 38

- AL (amyloid light chain) - AA (amyloid associated) - ABeta ( alzheimers disease)

Question 39

what is pathological pigmentation?

Answer 39

build up of pigmented substances in cytoplasm

Question 40

give examples of endogenous pigmentation

Answer 40

- haemosiderin (bruise) | - melanin

Question 41

give examples of exogenous pigmentation

Answer 41

- carbons deposits in macrophages of alveoli (anthracosis) - tattoo - heavy metal salts - intravascular drug use

Question 42

what is pathological calcification?

Answer 42

a lesion in which calcium salts, usually in the form of calcium phosphate, are deposited abnormally in soft tissues

Question 43

what are the the 2 forms of pathological calcification?

Answer 43

- dystrophic | - metastatic

Question 44

what is is dystropic pathological calcification?

Answer 44

Ca phosphate in necrotic tissue

Question 45

what is metastatic pathological calcification?

Answer 45

Ca salts in vital tissue (connective, BV)

Question 46

what causes pathological calcification?

Answer 46

- increased parathyroid hormone, parathyroid tumour - destruction bone tissue - excess vit D - renal failure

Question 47

state the differences between apoptosis and necrosis

Answer 47

apoptosis - no inflammation, requires energy, cell shrinks, plasma membrane necrosis - inflammation, no energy, plasma membrane disrupted

Question 48

state 2 microscopical characteristics of cellular reversible injury?

Answer 48

- fatty changes | - cloudy swelling