cell injury

Question 1

what is reversible cell injury?

Answer 1

cells adapt to change in environment and return to normal once stimulus removed

Question 2

what is irreversible cell injury?

Answer 2

permanent and results in cell death

Question 3

what does whether cell injury is reversible or irreversible depend on?

Answer 3

type, duration, severity and adaptability/ susceptibility of cell

Question 4

what are some causes of cell injury?

Answer 4

hypoxia
physical agents eg. radiation
chemicals
drugs
infection
genetics
nutritional imbalance

Question 5

what is hypoxia and what does it cause?

Answer 5

deficiency of oxygen
causes anaemia and respiratory failure

Question 6

how do cells still release energy in hypoxia?

Answer 6

anaerobic mechanisms

Question 7

what is ischaemia? what causes it?

Answer 7

reduction in blood supply to tissue
caused by blockage of arterial supply or venous drainage

Question 8

what does ischaemia lead to a depletion of?

Answer 8

oxygen nutrients

Question 9

do cells produce energy in ischaemia?

Answer 9

no its more rapid and serve than hypoxia

Question 10

give examples of physical agents that cause cell injury?

Answer 10

ionising radiation
mechanical trauma
electric shock
temperature extremes

Question 11

what are examples of infectious agents that cause cell injury?

Answer 11

bacteria
viruses
fungi
parasites

Question 12

what are immunological reactions that cause cell injury?

Answer 12

hypersensitivity
anaphylaxis
inflammation

Question 13

what happens when you have too many and too little nutrients in general?

Answer 13

anorexia and obesity

Question 14

what happens to the cell in reversible cell injury?

Answer 14

cloudy swelling and fatty change

Question 15

what is cloudy swelling?

Answer 15

cells can maintain fluid and ionic homeostasis
failure of pumps

Question 16

what is fatty change’?

Answer 16

accumulation of lipid vacuoles
liver enlarged and pale

Question 17

what type of cell injury is necrosis?

Answer 17

irreversible

Question 18

what happens in necrosis?

Answer 18

cell membrane disrupted therefor cell contents leak
inflammatory response
phagocytosis

Question 19

name some microscopic changes of necrosis?

Answer 19

pyknosis
karyorhexis
karyolysis

Question 20

what is pyknosis?

Answer 20

nucleus stinks and stains darker

Question 21

what is karyorrhexis?

Answer 21

nucleus fragments

Question 22

what is karyolysis?

Answer 22

blue staining nucleus is digested by endonuclease

Question 23

how would you identify necrotic cell on histological image?

Answer 23

blue nucleus fades away and if its still there its smaller and darker

Question 24

name 3 types of necrosis?

Answer 24

coagulative
liquefactive
caseous

Question 25

what happens in coagulative necrosis?

Answer 25

no proteolysis of cell death due to denaturation of enzymes

Question 26

what happens in liquidate necrosis?

Answer 26

dead tissues digested so tissue on liquid viscous state

Question 27

what happens in gaseous necrosis?

Answer 27

looks like cheese seen in tuberculous infection

Question 28

what is gangrenous necrosis?

Answer 28

coagulative necrosis to liquefactive necrosis

Question 29

what is fat necrosis?

Answer 29

focal areas of fat destruction - liquefied

Question 30

what is fribrinoid necrosis?

Answer 30

special type of necrosis seen in immune reactions of blood vessels antigen antibody complexes in artery walls

Question 31

what does necrosis cause?

Answer 31

inflammation phagocytosis scar formation

Question 32

how do you know if a cell is dead?

Answer 32

alive nuclei is blue and red dead nuclei is black

Question 33

what is apoptosis?

Answer 33

genetically programmed cell death

Question 34

how are apoptosis and necrosis different?

Answer 34

apoptosis doesn't cause inflammation necrosis = swell apoptosis = shrink necrosis plasma membrane is disrupted but in apoptosis its intact

Question 35

what triggers apoptosis

Answer 35

hypoxia/ischaemia viral infections DNA damage cascade enzymes

Question 36

what does apoptosis do in thymus?

Answer 36

deletes self reactive lymphocytes

Question 37

what does apoptosis do in epithelium?

Answer 37

deletes proliferating cells

Question 38

what does apoptosis do after an inflammatory response?

Answer 38

deletes the inflammatory cells

Question 39

stages of apoptosis?

Answer 39

1. cells shrinks 2. chromatin condenses 3. cytoplasmic blebs form 4. break off and form apoptotic bodies 5. phagocytoses

Question 40

what is atherosclerosis?

Answer 40

accumulation of cholesterol in macrophage and sm cells in BV walls

Question 41

what causes deposits of amyloid?

Answer 41

axing drugs chronic inflammation

Question 42

what is endogenous pigmentations?

Answer 42

melanin bilirubin BROWN

Question 43

what is exogenous pigment?

Answer 43

tattoo carbon smoke

Question 44

what is dystrophic pathogenic calcification?

Answer 44

deposits of calcium phosphate in necrotic tissue serum calcium is normal

Question 45

what is metaplastic pathogenic calcification?

Answer 45

deposits of calcium salt in normal tissue raised serum calcium levels

Question 46

what effects does raised serum calcium have?

Answer 46

- hyperparathyroidism and parathyroid gland tumour - excess vit d - destruction of bone tissue - renal failure