Healing And Repair Flashcards
Define Repair
Involves regeneration and scar formation and therefore the associated fibrosis
What are the three parts of the wound healing process
Heamostasis, inflammation and regeneration
What are the three different types of tissues
Labile, Stable and Permemant
What type of cell division do stem cells display?
Asymmetric division
What do growth factors do?
Promote proliferation in the cell population
What are two of the factors controlling regeneration?
Contact between basement membrane and adajecent cells
How does contact with the basement membrane affect cell regeneration
Loss of contact inhibition between cells encourages the proliferation of different cell types, and there is often signalling throughout he different adhesion moelcules involved
what factors determine whether aa tissue wil resolve after injury or not.
Whether the necrosis was of labile, stabile or permenant cell popultions, and whether the collagen framework remains intact
What are the key components of fibrous repair?
Angiogenesis, cell migration, extracellular matrix production and remodelling
What are the different stages of angiogenesis?
Endothelial proteolysis of the basement membrane, migration of Endotheial cells via chemotaxis, migration of endotehail cells via chemotaxis, endotheial proliferation, endothaiel maturation and tubular remofdeelin and recruitment of periendotheiel cells.
What are some disorders of collagen syntehsis?
Vitamin C deficeincy, Ehlers Danos Syndrome, Scurvy
What are the 3 overarching stages of the mechanism of fibrous clot repair?
The inflammatory cell infiltrate, the clot replacement by granulation tissue, Maturation of the clot.
What is involved in the inflammatory cell infillrate stage of fibrous clot repair?
Blood clot forms, there is the development of chronic inflammation, macrophages and lymphocytes migrate into the clot.
What are the details of the granulation tissue stage of fibrous repair?
Angiogenesis, Myofibroblasts migrating and differentiating, extracellular matrix is produced by Myofibroblasts.
What are the details of the maturation stage of fibrous clot repair>
Comparitley long lasting, the cell population falls, collagen increases, matures nd remodes, vessels differentiate and are reduced and you are left with a fibrous scar.
What are the two mechanisms of repair of skin?
Healing by primary intention and healing by secondary intention.
What are the features of a wound which heals by primary intention?
Clean wounds that have opposed edges, icisionol, closed, and non infected wounds
What are the features of a wound that heals by secondary intetnion?
Excisional wounds with tissue loss and unopposed edges.
What are some stages of the process of wound healing by secondary intention?
Open wound filled with abundant granulation tissue from the edges, considerable wound contraction is needed to close the defect, which is firstly caused by the contraction and shrinkage of the scab, and after a week the Myofibroblasts invade and contract.
What are the stages of healing a bone fracture?
Formation of a heamotoma, formation of a firbin mesh and then graunlation tissue, formation of a soft callus, then a hard callus or a bony callus, formation of lamellar bone, remodelling based on Mechinal stresses
Name some of the local factors that influence healing and repair?
Size, location and type of wound, blood supply, denervation, locl infection, foreign bodies, heamotoma, mechinal stress, necrotic tissue
What re the systemic factors that influence healing and repair?
Anemia, Hpoxyi, hypovalvima, obesity, diabetes, malgiancy, genetic disorders, malnution.
What are some of the possible complications of fibrous repair?
Formation of firbos adhesions, loss of function(due to loss of specialised parenchymal tissue), disruption of complex tissue , obstruction to tubes (Contractures)
What are the healing features of cardiac tissue?
Limited if any regenerative capcity, therefore a myocardial infraction is often followed by the formation of scar tissue
