Flashcards in Regeneration and repair Deck (53):
What are the 4 phases of tissue repair?
3. Reparative (proliferative)
4. Wound contraction and scarring (not always)
What is Hemostasis?
What is involved in the inflammatory step of tissue repair?
Infiltration of immune cells, initiation of repair
What is involved in the reparative phase of tissue regeneration?
Migration of cells, Formation of granulation tissue
What phase of tissue repair involves the transition of blood from a liquid to a fibrillar gel?
What is the primary goal of hemostasis?
Stop the bleeding
What is the secondary goal of hemostasis?
Initiation of healing
What leads to the coagulation cascade?
Disruption of platelets
In hemostasis the _____ unites the edges of wound, and ________ provides a scaffold for future cell migration and repair
How is a clot in the oral cavity different than the rest of the body?
Softer, more easily detached
What type of Hemostasis is described as the "Platelet Plug"?
Vascular spasm (constriction) and initial platelet plug in a damaged blood vessel happens in which type of hemostasis?
In primary Hemostasis, initiation of it occurs by exposure of collagen in _______ to circulating _______ factor
2. Von Willebrand factor
What does Von Willebrand factor do?
Causes platelet aggregation by interacting with platelet surface proteins
What receptor complex is associated with the function of von Willebrand factor?
How would platelets bind collagen directly?
via GPVI (Glycoprotein VI) and a2B1 integrin
In Primary hemostasis, Platelets activate and dump out tons of preformed cytoplasmic vesicles containing more _____, _____, and _______, and _____
3. Coagulation factors V and XIII
4. Platelet agonists serotonin and ADP
What anchors platelets together?
When does Secondary Hemostasis happen?
Simultaneously with or just after primary hemostasis
What is the main feature of secondary hemostasis?
T/F The cascade of Secondary hemostasis is a very simple one
False, it is fairly complex
What are the two pathways of secondary hemostasis?
What is the Extrinsic pathway of secondary hemostasis?
1. Factor VII and tissue factor interactions (found around, often on fibroblasts), initiating cascade
*It is called extrinsic because it requires tissue factor which isnormally not found in blood
In secondary hemostasis, what is the intrinsic pathway?
1. Initiated by damaged endothelium (collagen exposure)
*Called intrinsic because it involves factors found in the blood (i.e. not tissue factor)
The main point of hemostasisis the conversion of ______ into ______
What does thrombin do?
Converts soluble fibrinogen into insoluble fibrin
Many of the steps in clotting require what?
How does fibrin form a blood clot?
Cross-links and form a mesh, trapping red an white cells, resulting in blood clot
What are the first cells on the scene in an inflammatory response?
How are neutrophils activated?
Antibody-antigen interactions, LPS, complement system
What cells arrive second in inflammation?
What phase of tissue repair involves cell migration under fibrin clot and creates a highly cellular granulation tissue?
*Mobilization of adjacent cells
What does Epithelial cell migration do in reparative/proliferative phase?
1. Formation of new basal lamina
2. redistribution of integrin receptors
3. Formation of new hemidesmososmes (cells form their own track)
*Eventually forms a thin cover around the wound
In reparative phase, ____ recruitment occurs, with proliferation of _______ in the wound
The fibroblasts recruited to the wound are both resident and new ones from mesenchymal progenitor cells T/F
In what phase do we get Endothelial cell proliferation andangiogenesis and what factors are involved in this?
2. TGFB, VEGF, FGF-2
What are the specialized fibroblasts involved in wound crontraction?
How do myofibroblastsperform wound contraction?
Align around the wound, form cell junctions and attach to connective tissue fibrin around wound (purse string)
T/F the initial collagen deposis by fibroblasts is very mobile.
False, immobile scar tissue and can be remodeled
T/F Generally there is no scarring of the oral mucosa
What can arrest the spread of infection into periodontal tissues?
In periodontal disease, if the source of inflammation is removed what may happen?
It may be the formation of a fibrin clot that stimulates reattachment of connective tissues
Repair mechanism of PDL is broadly the same as in what organ?
What is different in PDL repair as opposed to skin repair?
Immediate remodeling of collagen by ligament fibroblasts = no scar
What can we add to PDL repair to encourage ligament reattachment?
What are the 3 primary zones in Dental Caries?
1. Surface and Body
2. Dark Zone
3. Translucent Zone
Describe the surface and body zone in dental caries?
Surface zone re-mineralizes, body is the primary zone of demineralization
Describe the dark zone of dental caries
Zone of increasing demineralization
Describe the transluscent zone of dental caries
Leading edge, caused by micro-pores which form in the enamel rod boundaries
How are caries dynamic?
Continual de-mineralization and re-mineralization, but a net loss
What are the 3 key components of Tissue Engineering?
1. Cell source
3. Bioactive Component
Define Bioactive materials
Materials which are designed to drive repair/regeneration through the use of bioactive factors