Cellular Response To Stress And Injury Flashcards
(41 cards)
How can you tell the difference between an alive or dead cell under a microscpe
Alive cell has nucleus stained
Dead cell has nucleus gone
What ar the 5 processes that occur in cell injury
- Adaptation
- Cell injury
- Reversible injury
- Irreversible injury
- Cell death
What occurs in adaptation
The cells respond to stress
What causes cell injury to occur
Failure of the cell to adapt to a particular stress
When does reversible injury occur
When the cell injur is mild or transient so it can go back to being a normal cell
What causes irreversible injury to occur
When the cell injury is severe or progressive so the injury becomes irreversible
What occurs in cell death
This occurs after irreversible injury, the cell with die by necrosis or apoptosis
What are the 4 main ways of adaptation
- Hyerplasia
- Hypertrophy
- Atrophy
- Metaplasia
What is hyperplasia
Increase in number of cells by hormonal and chemical stimnulus
How do we get hyperplasia
Increasing number of cells entering the cell cycle
How does bening prostatic hyperplasia occur
- DHT (andorgen derived from testosterone) is the stimulus
- This results in hyperplasia of epithelail and stromal cells
- This causes the compression of the urethra
- Urine therefore cant drain freely
What is the treatment for BPH
5 alpha reductase
What is the mechanism of action of 5 alpha reductase
Inhibit the production of DHT
What is hypertrohy
Increase in the size of the cell due to a mechanical stimulus
What is the mechanism of hypertrophy
- Mechanical stimulus acitvates signal transduction pathway
- This increases the synthesis of contractile protein in the cell which increases the mechanical performance of the cell
Name a pathological event of hypertrophy
Left ventricular hypertrophy
What occurs in left ventricular hypertrophy
- This occurs as a result ot mechnial pressue of sytemic hypertension
- Ventricular hypertrophy occurs so the left ventricles have more power to work against pressue
- Overtime left ventricular hypertrophy is too great which impairs the heart as it becomes stiff
- This impairs the diastolic filling
What is atrophy
This is the decrease in the size of tissue or number (opposite of hypeplasia and hypertrophy)
Name a physiological example of atrophy
Post pubertal atrophy of the thymus gland which is part of the ageing process
Name a pathological example of atrophy
Brain atrophy
What is metaplasia
Replacement of one differentiated cell type by another differitated cell type which occurs as a result of unfavourable environmental
Name an example of metaplasia in the bronchus due to smoking
Ciliated columnar epithelium become squamous epithelium (this is resistant to the damaging effects of smoking)
Name an example of metaplasia that occurs in the lower oesphagus due to acid reflux
Squamous epithelum becomes gastric columnar type epithelum
Name an example of metaplasia that occurs in the stomach due to chornic inflammation
Gastric columnar epithelium becomes intestinal type columnar epithelium
