Cell injury and cell death

Question 1

What are the 3 responses to cellular stress

Answer 1

1. Adaption
2. Reversible cell injury
3. Irreversible cell injury/death

Normal cell function maintained in balance - homeostasis
Exposed to severe stress
Adaption- stress by GAST
Changes into cell - more tolerating to environment
If this level of stress prolonged - cause cell injury
If level not sufficient to irreversible damage -
Expose cell to severe stress or injury - irreversible - cell death

Question 2

describe the heart and an example of repose to stress and injury

Answer 2

• Cardiac Myocytes can adapt as result of increased loads
  HIgh blood pressure - work harder
  Myocyte hypertrophy - heart muscle becomes bigger resulting in thickened myocardium
• If the cells were reversible injured for example or sudden temporary reduction in oxygen supplied to the cell, then the cell can undergo reversible changes, which most often than not visible under the microscope
• However the reversible changes regress once the blood supply or the nutrient supplier returned
• IF the insult is severe , if there is marked reduced blood flow to the heart through,blockage in the coronary arteries , then there is irreversible myocyte injury and cell death
  In this situation this would be an myocardial infarction

Question 3

What are causes of cell injury and death

Answer 3

Oxygen deprivation affects cell to produce ATP
Cause by loss of blood supply
Lung disease or anaemia

Physical ( trauma, heat )
Chemical - poisons , environmental pollutants
Autoimmune reaction -
Nutritional imbalances- calorie deficits
Ageing- slow progressive form of cell injury

Question 4

what are the mechanisms of cell injury

Answer 4

Question 5

describe how the 6 mechanisms of cell injury affect cells

Answer 5

Question 6

describe how ATP depletion affects mechanism of cell injury

Answer 6

Deficient of oxygen - ATP function affected
Hypoxia and cyanide

• ATP is critical for energy dependant functions
• membrane transport
  maintenance of ionic gradients
• protein , DNA, RNA synthesis
• Efficient production of ATP requires oxygen
• Impaired production/depletion can occur in hypoxia and toxins

Question 7

Describe how mitochondrial damage affects mechansims of cell injury

Answer 7

Question 8

how does increased intra cellular calcium affect mechanisms of cell injury

Answer 8

• Increase calcium releases calcium in ER
• Activates harmful intracellular enzymes
• Cell injury can occur

Question 9

Describe how ROS - affects mechanisms of cell injury

Answer 9

Question 10

draw the diagram of ROS and how it affects cell injury

Answer 10

Question 11

How is membrane damage affecting mechanisms of cell injury

Answer 11

Question 12

Describe how DNA damage and protein mis-folding affect mechanisms of cell injury

Answer 12

Question 13

what are the microscopic and ultrastructural features of reversible cell injury

Answer 13

Question 14

what are 2 forms of cell death

Answer 14

Question 15

describe the difference between necrosis vs apoptosis

Answer 15

Question 16

what are the morphological patterns of necrosis

Answer 16

Question 17

what is apoptosis (4)

Answer 17

Question 18

describe physiological examples of apoptosis

Answer 18

Question 19

what are pathological examples of apoptosis

Answer 19

Question 20

what are 2 main pathways of apoptosis

Answer 20

Question 21

what is morphology of apoptosis

Answer 21

Question 22

give summary table of necrosis vs apoptosis

Answer 22

Question 23

describe examples cell death and clinical diagnosis

Answer 23

Question 24

what are cellular adaptions

Answer 24

Question 25

what is hyperplasia

Answer 25

Question 25

what is hypertrophy

Answer 25

Question 26

what is atrophy

Answer 26

Question 27

what is meta plasia

Answer 27

• Lining of cell changes
• Squamous cells - try to adapter be better suited to environment
• Columnar metaplasia in oesophagus