Healing and Repair Flashcards
What is regeneration?
replacement with functional, differentiated cells
What is meant by repair?
production of fibrous scar and changes in tissue structure/architechture
How do you tell between regeneration or repair?
depends on severity and location of damage- some tissues have better regenerative capacities than others
Can epithelial tissue regenerate?
if destruction isnt too deep
what are three cell types in regeneration/ repair?
Labile cells- normal state is active cell division, rapid regeneration
stable cells(continual renewal cells)- variable rates of regeneration, rapid proliferation in response to injury
Permanent cels- unable to divide, unable to regenerate
Where are labile cells common?
epithelial cells and hematopoietic stem cells
where are stable cells commonly found?
liver and kidney
where are permanent cells usually found?
heart and muscle
What are the 4 stages of healing?
coagulation phase- clotting , inflammation phase-inflammatory cells migrate, proliferation phase-fibroblast migration, activation, maturation phase, tissue remodling/resolution
What stage of healing are growth factors essential?
Proliferation phase
What tissue is formed in proliferative phase?
formation of granulation tissue- eventually a new connective tissue rich in collagen
Summarise the 2 phases of granulation tissue?
1- vascular granulation tissue, mix of capillaries, fibroblasts, immune cells. new capillaries- leaky- cells and fluid into tissue
2- fibrous granulation tissue- over time capillaries regress and immune return to blood, lay down collagen
What is angiogenesis?
formation of new capillaries (blood vessels)
formed by sprouting, intussusceptive(splitting)
What process do Vascular endothelial growth factors drive?
angiogenesis
What key roles do growth factors play?
cytokines, hormones
promote or inhibit cell growth and differentiation
bind receptor on cell surface
homeostatic production- balance in health
