Flashcards in MOD8- Repair & Regeneration Deck (28):
what is healing by regeneration?
it is returning tissue to normal function ie restitution of specialised function
what is healing by repair
it is healing by fibrosis and scarring ie loss of specialised function
what are the 3 different cell population theoretically
labile cell population, stable cell population, permanent cell population
what is labile cell population
high normal turnover(excellent regenerative capacity) eg epithelium, active stem cell population, usually heal by regeneration
what is another name for stable cell populatio
quiescent cell population
what is stable/quiescent cell population
low physiological turnover (turnover can massively increase if needed ie has good regenerative capacity) eg liver, renal tubules
what is permanent cell population
they are cells which do not have physiological turnover ie long life cells & no regenerative capacity eg neurons & muscle cells
what is required in order for regeneration to take place properly
previously existed architectural framework
what does regeneration of tissue depends on?
previously existed architectural framework , stem cells
what is a stem cell niches
it is a specific anatomical places where stem cells are stored within the human body
what controls regeneration
proliferation of stem cells/amplifying cell compartment, covering of defect, contact inhibition (proliferating cells will stop proliferating as they come into contact with each other in epithelium), complex control by growth factors, cell-cell & cell-matrix interactions
when will healing by repair take place?
normal structures which can not be replaced
what are the 3 main components of granulation tissue?
new capillary loops (around the dead muscles), phagocytic cells (neutrophils, macrophages), (myo)fibroblast - fibroblast which has muscle filament involved
what locally can inhibit healing by repair
presence of infection, foreign bodies, hematoma (clogged blood stoping physically the healing of the wound especially after surgery), lack of blood supply, mechanical stress
what systemically inhibit the healing by repair
age, drugs - especially those creating a catabolic state (eg steroids), anaemia(restricting blood supply), diabetes (restricting blood supply & causes metabolic deficit in cells) , malnutrition, catabolic states, Vit C deficiency (cofactor for collagen), trace metal deficiency
what is catabolic state
state in which the body is breaking larger molecules into smaller molecules
what is healing by first intention in surgery inflicted wound
it mean a clean, uninfected surgical wound with good haemostasis and edges apposed eg with sutures or staples
what is organisation of a wound
it is turning a granulation tissue into fibrous scar
what is healing by second intention in surgery?
it is wound edges apposed (not toughing side to side) due to extensive loss of tissue etc
what is the process of fracture bone healing?
once fractured - haematoma is formed - haematoma is then organised - osteoblast lay down callus bone - callus bone - remodel according to mechanical stress - replace by lamellar bone eventually
what is callus bone
it is woven bone
what lay down callus bone
what will replace callus bone
lamellar bone wil
what will cause healing by second intention
extensive loss of tissue - apposition not physically possible - large haematoma - infection - present of foreign body
what make healing as a process different in the brain and bone?
neurones are terminally differentiate (not regenerable), supporting tissue = glial cells (rather than collagen and fibroblast)
however the overall healing process is the same really
instead of fibrosis, what process will take place instead?
gliosis - carried out by glial cells within the brain
what does damaged area of the brain is left with a cyst ?
it is because the damaged tissue is removed by glial cells rather than collagen & fibroblast ie no granulation tissues.