Injuries To Cells

Question 0

What three things are cells lost or changed by during irreversible cell damage?

Answer 0

Apoptosis - cell suicide
Necrosis - cell death
Neoplasia - cancer

Question 1

What four things do cells adapt by during reversible cellular repair and recovery?

Answer 1

Hyperplasia
Hypertrophy
Metaplasia
Atrophy

Question 2

What is hypertrophy?

Answer 2

Increase in the size of cells

Question 3

Hypertrophy can be….

Answer 3

Physiological or pathological

Question 4

What type of drug can cause hypertrophy?

Answer 4

Steroids

Question 5

What is hyperplasia?

Answer 5

Increase in cell number resulting in larger organ

Question 6

What can hyperplasia occur along side by?

Answer 6

Hypertrophy

Question 7

Hyperplasia can be

Answer 7

Physiological

Pathological

Question 8

What is atrophy?

Answer 8

Shrinkage of the size of the cell by loss of cell substance

Question 9

Atrophy is due to what 5 things?

Answer 9

Decreased workload, reduced blood supply, inadequate nutrition, loss of hormonal stimulation, ageing.

Question 10

What is metaplasia?

Answer 10

One adult cell type is replaced by another adult cell type.

Question 11

Is metaplasia reversible?

Answer 11

Yes

Question 12

In metaplasia what might the new type of cell be more able to withstand?

Answer 12

Stress

Question 13

Give an example of metaplasia

Answer 13

Chronic gastro - oesophageal reflux

Question 14

List 8 causes of cell injury

Answer 14

Hypoxia
Ischaemia 
Chemical exposure eg cigarette smoke, alcohol...
Infection
Radiation
Lack of nutrients
Immunologic reactions
Ageing

Question 15

Give three features of cell necrosis

Answer 15

Damage to membranes allows enzymes to digest cell.
Local inflammation.
Always pathological.

Question 16

Give three features of apoptosis

Answer 16

Programmed cell death.
Irreparable damage to cells protein/DNA. Deprived of growth factors.
Can be pathological or physiological

Question 17

Describe the three stages of apoptosis

Answer 17

Cells activate enzymes that degrade the cells own DNA and proteins resulting in death.
Fragments of the apotopic cell break off.
Dead cell rapidly removed by phagocytosis.

Question 18

Describe four features of physiological apoptosis

Answer 18

Embryogenesis
Involution of hormone dependent tissues upon hormone deprivation.
Elimination of cells which have served their purpose.
Elimination of potentially harmful self reactive lymphocytes.

Question 19

List five pathological conditions of apoptosis

Answer 19

DNA damage.
Accumulation of misfolded proteins eg prions in Alzheimer’s.
Infections eg hepatitis
Pathological atrophy in parenchymal organs after duct obstruction.
Cell death induced by cytotoxic T cells.

Question 20

What does apoptosis result from?

Answer 20

The activation of enzymes called caspases - mitochondrial (intrinsic) pathway and fas receptor (extrinsic) pathway.

Question 21

What are the 4 types of necrosis?

Answer 21

Coagulation necrosis
Liquefactive necrosis
Caseous necrosis
Fat necrosis

Question 22

Causeous necrosis is caused by what illness?

Answer 22

TB

Question 23

Liquifactive necrosis is caused by..

Answer 23

Stroke

Question 24

Fat necrosis happens when

Answer 24

Fat is damaged by lipases due to trauma, released by damaged pancreas, fat is released into the blood stream causing a generalised septic response that damages other tissues

Question 25

List the 6 mechanisms of cell injury

Answer 25

``` Depletion of ATP Mitochondrial damage Influx of calcium Oxidative stress Damage to the cell membrane DNA damage ```

Question 26

Why is there a depletion of ATP in cell damage?

Answer 26

Reduced oxygen and nutrient supply, leads to mitochondrial damage, cells can't regain sodium content and lactic acid and toxins are released into the blood stream.