Trigger 6: Wound Healing Flashcards
tissue repair definition
the regeneration of damage tissue by parenchymal cells of the same type or replacement by connective tissue (scar)
parenchymal cells
the functional parts of an organ
connective tissue is
scaring
causes of damage
trauma, infection, physical or chemical agents tissue necrosis, immune reactions
immune reactions e.g.
hypersensitivity reaction - asthma or anaphylaxis
what are the four phase of tissue repair (in order)
- Haemostasis
- Inflammation
- Proliferation
- Remodelling
- Haemostasis
platelet aggregation and clotting which leads to the release of pro-infllamtory mediated
when does haemostats occur
within hours of damage
platelets during haemostats causes
a fibrin plug to form- prevent bleeding
platelets recruit
inflammatory cells using cytokines and growth factor
what occurs after haemostasis
inflammation
- Inflammation causes
diapedesis
diapedesis
the passage of white blood cells through the intact walls of the lung capillaries, typically accompanying inflammation.
inflammation occurs within
hours
role of inflammation
recruitment of neutrophils, monocytes and macrophages
- wound debridement
wound debridement
removal of dead, damaged, or infected tissue to improve the healing potential of the remaining healthy tissue.
what happens after inflammation
proliferation
- Proliferation
alterations to cell-cell and cell-matrix interactions
proliferation involved
cross talks between MMPs, interns, cytokines/GF and ECM production which cause migration of cells
when does proliferation occur
within days
proliferation causes what to happen (4)
- re-epithelialisation
- angiogenesis
- fibroplasia
- ECM deposition
fibroplasia
process of forming fibrous tissue (fibroblasts)
extra cellular matrix
a three-dimensional network of extracellular macromolecules:
1) collagen
2) enzymes
3) glycoproteins
provide structural and biochemical support of surrounding cells
what happens after proliferation
remodelling
- Remodelling
involves fibroblasto to myofibroblast differentiation
when does remodelling occur
within weeks/ months
remodelling involves
ECM remodelling and degradation, contraction and scar formation
which cells are important during aberrant wound healing in lung fibrosis?
- epithelial
- macrophage
- fibroblast
- myofibroblast
- endothelial cells
aberrant wound healing
abnormal wound healing
haemostats simple
Is a process which causes bleeding to stop, meaning to keep blood within a damaged blood vessel. It is the first stage of wound healing. This involves coagulation, blood changing from a liquid to a gel.
fibroblast
Involved in formation of extracellular matrix (ECM). Differentiate into myofibroblasts
fibroblast differentiate into
myofibroblasts
myofibroblasts
a cell that is in between a fibroblast and a smooth muscle cell in phenotype
extracellular matrix provides
- structural support
- regulates movement and growth of cells
what is the ECM made up of
collagen- structural support
elastin- elastic stretch and recoil
proteoglycan- regulate ECM structure and permeability
adhesive glycoproteins
interns
collagen
tensile strength
elastin
elastic stretch and recoil
proteoglycan
regulates ECM structure and permeability, binds GFs
which adhesive glycoproteins
fibronectin and laminin
integrins
major cell surface receptor family- mediating cell adhesion to ECM
