Flashcards in Cell Pathology 1 Deck (36):
What are the 8 causes of cell injury?
1. Oxygen Deprivation
2. Chemical Agents
3. Infectious Agents
4. Physical Agents (trauma)
5. Genetic defects
6. Nutritional imbalances
7. Immunological reactions
What could oxygen deprivation in a major part of the body(e.g. coronary arteries) lead to?
What does the cellular response to injury depend on?
1. Type of injury
2. Severity of injury
3. Duration of injury
What do the consequences of cell injury depend on?
1. Type of cell
2. The cell's status
(3. Ability to adapt
4. Genetic makeup)
What is the sequence of cell death?
1. Cell function ceases
2. Cell death occurs
3. Morphological changes seen
What are the 4 vulnerable intracellular systems?
1. Cell membrane integrity
2. ATP production
3. Protein synthesis
4. Integrity of genetic apparatus
What is atrophy?
1. Shrinkage in cell size
2. by loss of cell substance
Give 2 examples of atrophy
2. Pernicious anaemia
1. Increase in size of cells
2. Consequently increase in size of organ
3. Can be physiological or pathological
4. Caused by increased functional demand or hormone stimulation
Give an example of hypertrophy.
Physiological hypertrophy (e.g. uterus or when muscle builds)
1. Increase in number of cells
2. Can be physiological or pathological
3. Physiological hyperplasia can be hormonal or compensatory
4. Pathological Hyperplasia is usually due to excess hormonal/growth factor stimulation.
Give an example of hyperplasia.
Proliferating endometrium (menstrual cycle - pays) or carcinoma (path).
1. Reversible change when one adult cell type is replaced by another.
2. Can be physiological process or pathological.
Give examples of metaplasia.
Physiological - cervix (puberty when cells change)
Barrett's Oesophagus - acid reflux causes cells in oesophagus to change from squamous to columnar.
1. Precancerous cells
2. Show the genetic and cytological features of malignancy
3. NOT invading underlying tissue
Give an example of dysplasia
Retinal dysplasia - abnormal formation of retina in embryo
Barretts Oesophagus - sometimes dysplasia occurs instead of metaplasia.
What are the light microscopic changes visible that are associated with reversible injury?
1. Fatty changes (e.g. alcoholic fatty changes in liver)
2. Cellular swelling
What are the light microscopic changes associated with irreversible injuries?
1. Coagulative necrosis
2. Liquefactive necrosis
3. Caseous necrosis
4. Fat necrosis
What is coagulative necrosis?
When cells die, but are still recognisable as cells (e.g. MI)
What is liquefactive necrosis?
When cells die and become liquid (e.g. brain)
What is caseous necrosis?
Cells look "cheesy"
Dead tissues become granules, unrecognisable as cells (e.g. TB - almost exclusively)
What is fat necrosis?
1. Enzymes become free
2. Fatty autodigestion
3. Fatty acids produced
4. Release of Ca ions causes fat deposition.
(e.g. Acute pancreatitis).
What is apoptosis?
1. Programmed cell death, requires energy
2. No inflammatory response
3. No secondary damage to surrounding tissue
What is necrosis?
1. When lots of cells die together.
2. Uncontrolled and unexpected
3. Inflammatory response occurs, meaning surrounding tissues are damaged.
What are the 3 nuclear changes associated with irreversible cell injury?
1. Karyolysis (nucleus lysed)
2. Pyknosis (nucleus shrunk)
3. Karyorrhexis (nucleus fragmented)
Why is there an inflammation response in necrosis?
1. Cell membrane integrity is lost.
2. Cell contents released to surrounding tissues.
3. Cell contents detected by immune system
4. Causes inflammatory response mediated by T cells.
What are the causes of apoptosis?
2. Deletion of auto-reactive T cells in Thymus
3. Hormone dependent physiological involution (shrinkage of an organ when inactive/old - e.g. uterus)
4. Cell deletion
5. Irreparable DNA damage can trigger apoptosis
What is the hallmark of apoptotic cells?
Pyknotic nuclei (shrunk nuclei).
What happens to apoptosed cells?
They are phagocytksed and disposed of by macrophages.
What 3 things is necrosis more than apoptosis?
1. More toxic
2. More severe
How can cancer occur?
When cancerous cells are not apoptosed.
3 differences between necrosis and apoptosis.
1. Necrosis is not dependent on energy, whereas apoptosis is an active energy dependent process.
2. Apoptosis may be physiological.
3. Apoptosis is not associated with inflammation.
What is another type of programmed cell death?
What is necroptosis?
1. Programmed cell death associated with inflammation.
2. Has many causes (e.g. viral infections).
What is lethal cell injury?
Produces cell death