Cell Injury And Fate

Question 1

Ischaemia

Answer 1

Where blood flow is restricted or reduced

Question 2

Infarction

Answer 2

Cell death due to ischaemia

Question 3

Lethal

Answer 3

Cell death

Question 4

Sublethal

Answer 4

Produces injury not amounting to cell death

Question 5

8 causes of cell injuries

Answer 5

• Oxygen deprivation
• Chemical agents
• Infectious agents
• Immunological reactions
• Genetic defects
• Nutritional imbalances
• Physical agents
• Ageing

Question 6

What 4 intravenous systems are vulnerable to cell injury

Answer 6

• cell membrane integrity
• ATP generation
• Protein synthesis
• the integrity of the genetic apparatus

Question 7

Atrophy

Answer 7

Shrinkage in size of cell or organ due to loss of cell substance
Dementia

Question 8

Hypertrophy

Answer 8

Increase is size of cell or organ
Can be caused by increased functional demands or specific hormonal situations,disease,muscle may grow due to exercise
Eg uterus

Question 9

Hyperplasia

Answer 9

Increase in number of cells in an organ

Physiological: can be either hormonal or compensatory eg endometrium

Pathological: usually due to excessive hormonal or growth factor stimulation eg carcinoma

Question 10

Metaplasia

Answer 10

A reversible change in which one adult cell type is replaced by another
Pathological-barrets oesophagus where normal oesophagus is lined with non keratinising squamous epithelia and stomach lined with columnar,acid reflux can change squamous cells to columnar
Physiological-cervical expansion during pregnancy results in columnar epithelium

Question 11

Dysplasia

Answer 11

Precancerous cells that show genetic and cytological features of malignancy but not invading underlying tissue

Question 12

Signs cell shows malignancy

Answer 12

Big nuclei and increased mitosis

Question 13

What are the 2 light microscopic changes associated with reversible cell injury?

Answer 13

Fatty change- after drinking lots of alcohol big white spots appear in hepatocytes however when drinking stops spots go away
Cellular swelling-ballooning degeneration where cytoskeleton damage causes proteins to accumulate in cells causing swelling

Question 14

Necrosis

Answer 14

Cell death associated with inflammation

Question 15

Coagulative necrosis

Answer 15

When structure of cells becomes fixed after cell death
Myocardial infarct

Question 16

Liquefactive necrosis

Answer 16

Where tissue becomes liquefied
Usually occurs in brain as brain doesn’t have connective tissue

Question 17

Causeous necrosis

Answer 17

Cells become structure less and oozy
Pulmonary TB

Question 18

Fat necrosis

Answer 18

e.g. in pancreas there are many digestive enzymes- if they become activated there instead of in duodenum they can digest pancreatic tissue- this includes lipases liquefying fat which causes fat necrosis

Question 19

Apoptosis

Answer 19

Programmed cell death of individual cells
Caused by embryogenesis eg fingers and joined together,deletion of auto reactive T cells in thymus to prevent autoimmune disease,hormone dependent physiological involutio. Eg in menstruation once hormones are released you get apoptosis
Cell deletion

Question 20

Necrosis vs apoptosis

Answer 20

• Apoptosis is physiological but may be pathological (e.g. seen in cancers)- necrosis is usually pathological
• Apoptosis is an ACTIVE energy dependent process so cells can maintain membranes and package organelles into apoptotic bodies- necrosis isn’t
• Apoptosis is NOT associated with inflammation unlike the neutrophilic inflammatory response we get from necrosis
• In necrosis usually we see sheets of cells dying (inflammatory response can damage nearby healthy tissue too) whereas apoptosis is usually at an individual cell level
• With necrosis, bits of cell membrane break off so the membrane loses integrity and there’s enzyme leakage- with apoptosis the cell breaks into apoptotic bodies where cell membrane doesn’t lose integrity

Question 21

Necroptosis

Answer 21

Programmed cell death associated with inflammation