PATH30001: MECHANISMS OF
HUMAN DISEASE MST 1 EXAM
QUESTIONS WITH CORRECT
ANSWERS
1) what are the hallmark molecular and cellular triggers of cell injury?
-- Answer ✔✔ - reduced ATP synthesis
- mitochondrial damage
- loss of calcium homeostasis
- disrupted membrane permeability
- free radical production
2) what are heat shock response genes and their role? -- Answer ✔✔ -
large group
- up-regulated expression in response to cell stressors
- protect proteins from stress-related damage
- clean up damaged proteins from the cell
- chaperone other proteins that protect the body for damage
3) what is pre-stressing? -- Answer ✔✔ - enabling tissues and organs to
survive significant injury by training/pre-stressing them
- can be done using pharmacological inhibitors that can lead to
sustained biochemical adaptation
- physiological adaptation
, - training cells to withstand injury
4) what are the morphological features of cell necrosis? -- Answer ✔✔
early (reversible):
- blebbing
- increased eosinophilia
- swelling
late (irreversible):
- loss of nuclei
- fragmentation
- leakage
- loss of architecture
5) what is hypoxia? -- Answer ✔✔ - injury caused by insufficient oxygen
supply due to reduced blood supply
- decreases levels of ATP
- limits metabolite substrates
- causes waste accumulation
- time dependent damage > can be repaired if treated early
enough otherwise if injury persists then mitochondria can be
irreversibly damaged and cause tissue death
- cells recover if oxygen and substrates are provided
6) what are the triggers of hypoxia? -- Answer ✔✔ - ischaemia (local or
systemic)
- hypoxaemia (oxygen problems like altitude or haemoglobin
problems like anaemia)
- oxidative phosphorylation inhibition (e.g. cyanide poisoning)
,7) what are effects of hypoxia? -- Answer ✔✔ - decreased oxidative
phosphorylation
- decreased ATP
- increased anaerobic glycolysis > decreased glycogen, increased
lactic acid > decreased pH > clumping of chromatin
- detachment of ribosomes > decreased protein synthesis
- decreased activity of Na+ pump > influx of Ca2+, water and Na+,
efflux of K+ > ER swelling, cellular swelling, loss of microvilli,
blebs
8) what are free radicals? -- Answer ✔✔ - highly reactive molecules
that can bind to and destroy cellular compounds and
macromolecules
9) what are the causes of free radical production? -- Answer ✔✔ -
chemicals and drugs
- reperfusion injury
- inflammation
- irradiation
- oxygen toxicity
- carcinogenesis
10) what are the effects of free radicals? -- Answer ✔✔ - lipid per
oxidation causing membrane damage
- protein modifications causing breakdown and misfolding
- DNA damage causing mutations
11) What is necrosis? -- Answer ✔✔ death of groups of contiguous
cells in tissue or organ that is unprogrammed
, 12) What is coagulative necrosis? -- Answer ✔✔ - most common form
of necrosis
- tissue architecture remains intact
- affect tissue remains solid
- necrotic cells are ultimately removed by inflammatory cells
- dead cell region may be regenerated or replaced by scar (fibrosis)
13) What is liquefactive necrosis? -- Answer ✔✔ - usually due to
massive infiltration by neutrophils causing abscess formation
- characteristic of ischaemic necrosis in the brain
- complete dissolution of necrotic tissue
- tissue architecture destroyed
14) what is caseous necrosis? -- Answer ✔✔ - form of coagulative
necrosis in which a thick, yellowish, cheesy substance forms
- accumulation of unstructured debris within an area of necrosis
- tissue architecture lost
- cells are no longer recognisable
- associated with granulomatous inflammation of TB
15) what is infarction? -- Answer ✔✔ - area of ischaemic necrosis in a
tissue or organ
- red is due to venous occlusion
- white is from arterial occlusion
16) what is apoptosis? -- Answer ✔✔ - mechanism of programmed cell
death
- requires energy
- physiological cell death
- can be triggered by lack of growth stimuli, death signals and DNA
damage
HUMAN DISEASE MST 1 EXAM
QUESTIONS WITH CORRECT
ANSWERS
1) what are the hallmark molecular and cellular triggers of cell injury?
-- Answer ✔✔ - reduced ATP synthesis
- mitochondrial damage
- loss of calcium homeostasis
- disrupted membrane permeability
- free radical production
2) what are heat shock response genes and their role? -- Answer ✔✔ -
large group
- up-regulated expression in response to cell stressors
- protect proteins from stress-related damage
- clean up damaged proteins from the cell
- chaperone other proteins that protect the body for damage
3) what is pre-stressing? -- Answer ✔✔ - enabling tissues and organs to
survive significant injury by training/pre-stressing them
- can be done using pharmacological inhibitors that can lead to
sustained biochemical adaptation
- physiological adaptation
, - training cells to withstand injury
4) what are the morphological features of cell necrosis? -- Answer ✔✔
early (reversible):
- blebbing
- increased eosinophilia
- swelling
late (irreversible):
- loss of nuclei
- fragmentation
- leakage
- loss of architecture
5) what is hypoxia? -- Answer ✔✔ - injury caused by insufficient oxygen
supply due to reduced blood supply
- decreases levels of ATP
- limits metabolite substrates
- causes waste accumulation
- time dependent damage > can be repaired if treated early
enough otherwise if injury persists then mitochondria can be
irreversibly damaged and cause tissue death
- cells recover if oxygen and substrates are provided
6) what are the triggers of hypoxia? -- Answer ✔✔ - ischaemia (local or
systemic)
- hypoxaemia (oxygen problems like altitude or haemoglobin
problems like anaemia)
- oxidative phosphorylation inhibition (e.g. cyanide poisoning)
,7) what are effects of hypoxia? -- Answer ✔✔ - decreased oxidative
phosphorylation
- decreased ATP
- increased anaerobic glycolysis > decreased glycogen, increased
lactic acid > decreased pH > clumping of chromatin
- detachment of ribosomes > decreased protein synthesis
- decreased activity of Na+ pump > influx of Ca2+, water and Na+,
efflux of K+ > ER swelling, cellular swelling, loss of microvilli,
blebs
8) what are free radicals? -- Answer ✔✔ - highly reactive molecules
that can bind to and destroy cellular compounds and
macromolecules
9) what are the causes of free radical production? -- Answer ✔✔ -
chemicals and drugs
- reperfusion injury
- inflammation
- irradiation
- oxygen toxicity
- carcinogenesis
10) what are the effects of free radicals? -- Answer ✔✔ - lipid per
oxidation causing membrane damage
- protein modifications causing breakdown and misfolding
- DNA damage causing mutations
11) What is necrosis? -- Answer ✔✔ death of groups of contiguous
cells in tissue or organ that is unprogrammed
, 12) What is coagulative necrosis? -- Answer ✔✔ - most common form
of necrosis
- tissue architecture remains intact
- affect tissue remains solid
- necrotic cells are ultimately removed by inflammatory cells
- dead cell region may be regenerated or replaced by scar (fibrosis)
13) What is liquefactive necrosis? -- Answer ✔✔ - usually due to
massive infiltration by neutrophils causing abscess formation
- characteristic of ischaemic necrosis in the brain
- complete dissolution of necrotic tissue
- tissue architecture destroyed
14) what is caseous necrosis? -- Answer ✔✔ - form of coagulative
necrosis in which a thick, yellowish, cheesy substance forms
- accumulation of unstructured debris within an area of necrosis
- tissue architecture lost
- cells are no longer recognisable
- associated with granulomatous inflammation of TB
15) what is infarction? -- Answer ✔✔ - area of ischaemic necrosis in a
tissue or organ
- red is due to venous occlusion
- white is from arterial occlusion
16) what is apoptosis? -- Answer ✔✔ - mechanism of programmed cell
death
- requires energy
- physiological cell death
- can be triggered by lack of growth stimuli, death signals and DNA
damage
