Flashcards in 8. Repair and Regeneration Deck (58)
Regenration occurs when?
After acute inflammation, if the cells can regrow
Repair occurs when?
After acute inflammation, if the cells cannot regrow
After regeneration, are the tissues normal or scarred?
Damaged cells replaced by like
Tissue returns to normal
After repair, are the tissues normal or scarred?
Damaged cells cannot be replaced by like
Fibrosis and scarring
After regeneration, do the tissues still have specialised function?
Yes, tissue restores specialised function
After repair, do the tissues still have specialised function?
No, loss of specialised function
Name 3 types of kinetic cell populations
What are the main characteristics of labile cell populations?
- high normal turnover
- active stem cell population
- excellent regenerative capacity
Give an example of a labile cell population
What does 'high turnover rate' mean in terms of tissues?
Constantly producing and shredding off old cells. Do this to maintain integrity
In which zone of the tissue do active stem cells sit?
In the basal zone
What does 'regenerative capacity' mean?
Capacity to heal by regeneration
What are the main characteristics of stable (quiescent) cell populations?
- low physiological turnover
- turnover can massively increase if needed
- good regenerative capacity
Give examples of stable (quiescent) cell populations
- renal tubules
What are the main characteristics of permanent cell populations?
- no physiological turnover
- long life cells
- no regenerative capacity
Give examples of permanent cell populations
- muscle cells
Cell types which are very specialised eg. neurones tend to be which type of cell population? (kinetics)
Permanent cell populations
Which cell populations are at the end of the differentiation capacity and have lost the ability to divide?
Permanent cell populations
Which type of cell population is good at switching on turnover when the need arises?
Which type of cell population constantly goes round the cell cycle?
Stable cell populations can come and go out of the cell cycle. At which stage do the go back in?
Why does a cirrhotic liver consist of regenerative nodules divided by fibrous septa?
There is a collapse of the reticulin (connective tissue) framework of the liver so that the regeneration of liver cells cannot repopulate the normal architecture
What noxious agents may cause long term persistent long term damage to the liver (cirrhosis)?
- some hepatitis viruses
- autoimmune damage
What are the stages from stem cells to terminal differentiation?
- stem cell compartment
- amplifying cell compartment
- differentiating compartment
- terminal differentiation
Name some features of stem cells
- prolonged self-renewal
- asymmetric replication
- reservoirs present in many adult tissues
- when a stem cell divides, it produces another stem cell as well as a cell that goes up in the diagram
What is crucial for regeneration to be able to take place?
Survival of stem cells
What can damage stem cells?
- full thickness burn
What controls regeneration?
- proliferation of stem cell/amplifying cell compartments
- covering of defect
- contact inhibition
- complex control by growth factors, cell-cell and cell-matrix interactions
Why might a cell population be incapable of cell renewal?
- may be a permanent cell population
- may be loss of stem cells