Lecture 3 Flashcards
What is atrophy?
Decrease/shrinkage in cell size.
What 3 changes can cells undergo in order to adapt?
Size, number and form.
What is hypertrophy?
Increase in cell size.
What is hyperplasia?
Increase in the number of cells in a tissue or organ.
What is metaplasia?
A differentiated cell of a certain type is replaced by another cell type, which may be less differentiated.
List and describe the 2 forms of hypoxic injury.
Ischemia - reduced blood supply.
Anoxia - total loss of oxygen.
What is a reperfusion injury?
When there is a sudden increase in oxygen which results in the production of free radicals.
List the 3 major effects of free radicals and reactive oxygen species.
- Lipid peroxidation.
- Alterations in proteins resulting in fragmentation of polypeptide chains.
- Alterations to DNA including breakage of single strands.
What is oxidative stress?
Disturbance in the balance between the production of reactive oxygen species and antioxidant defences.
What is necrosis?
The premature death of cells and living tissue.
How many forms of necrosis are there, and what are they?
- 5
- Coagulative
- liquefactive
- Caseous
- Fatty
- Gangrenous
How does coagulative necrosis occur and what happens to the intercellular proteins?
- Commonly results from hypoxia due to ishemia or chemical injury.
- Proteins are denatured and coagulated.
How does liquefactive necrosis occur and what role do neutrophils play?
- Ishemic injury to neurons and cell.
- Neutrophils release hydrolysed to kill bacteria resulting in liquefaction of bacteria and neighbouring cells (pus)
Caseous necrosis is caused by what?
And what 2 forms of necrosis is it a combination of?
- Typically caused by myobacteria fungi and some foreign substances.
- Combination of coagulative and liquefactive.
What is gangrenous necrosis?
Severe hypoxic injury.
