Regeneration And Repair Flashcards Preview

Oral Bio Quiz 4 > Regeneration And Repair > Flashcards

Flashcards in Regeneration And Repair Deck (31):
1

What is regeneration?

What is repair?

Regeneration - Complete restoration of tissue architecture and fx (good as new)

Repair - Restoration of fx, BUT altered architecture (scars)

2

What are the 4 phases of tissue repair?

Hemostasis - Clot formation

Inflammatory - Infiltration of immune cells and initiation of repair

Reparative (Proliferative) phase - Migration of cells and formation of granulation tissue

Wound contraction and scarring (not always though)

3

What is hemostasis?

Liquid blood to fibrillar gel

Primary goal - STOP the bleeding

Secondary goal - INITIATE healing

4

_________ of platelets leads to coagulation cascade.

Disruption

*Clot unites edges of wound, and FIBRIN provides a scaffold for future cell migration

5

T/F - Clot is different in the oral cavity. It is softer and more easily detached.

TRUE

6

What is Von Willebrand disease?

Lack of the Von Willebrand Factor
-This factor causes platelet aggregation by interacting with platelet surface proteins
—*THIS IS PROMINENT IN PRIMARY HEMOSTASIS

7

What is primary hemostasis?

Vascular spasm (constriction) and initial platelet plug in a damaged blood vessel

8

Platelets bind collagen directly via what 2 things?

GPVI
-Glycoprotein VI

Alpha2beta1 integrin

9

When does secondary hemostasis occur?

Simultaneously with primary hemostasis or just after primary

10

Secondary hemostasis has two pathways.

Extrinsic

Intrinsic

11

Tell me about extrinsic.

Factor VII and tissue factor interactions and that initiates the cascade

- Called extrinsic b/c it req’s tissue factor which is normally NOT found in blood

12

Tell me about intrinsic.

Initiated by damaged endothelium (due to collagen exposure)

- Called intrinsic b/c it involves factors found in the blood, not tissue factor

13

What is the main point of both pathways?

Conversion of prothrombin into thrombin, which converts soluble fibrinogen into insoluble fibrin

*Ca2+ is req’d at many steps

**Fibrin cross-links and forms a mesh, trapping RBCs and WBCs, resulting in a blood clot

14

What WBCs are first on the scene?

PMNs

15

What WBCs are second to arrive?

Macrophages

-Clear damaged tissue and foreign material

16

What are the main leukocytes involved?

T cells in particular

17

What happens in the reparative/proliferative phase?

Mobilization of adj cells (epithelium)

Cells migrate under fibrin clot - forming a “granulation tissue”

18

Collagen type IV is found where?

BASAL LAMINA

19

When epithelial cells migrate, what do they form?

New basal lamina

*Also redistribution of integrin receptors and formation of new hemidesmosomes

Then, fibroblast recruitment occurs, and proliferation of fibroblasts in the wound. Collagen fills the defect, forms a scaffold

20

What is angiogenesis?

Regeneration of blood vessels

*TGFbeta, VEGF, FGF-2 are factors important in healing the wound and blood vessels

21

What cells do wound contraction?

Myofibroblasts

22

What do myofibroblasts do?

Align around wound, form cell junctions, and attach to connective tissue fibrin around wound (like a purse string)

Wound is drawn together

23

Oral mucosa is typically not scarred. Why?

No one really knows

24

If the source of inflammation is removed in periodontal disease, the formation of what stimulates reattachment of connective tissues?

Fibrin clot

25

Gingivitis?

Periodontitis?

Gingivitis - Repair will occur once infection is removed

Periodontitis - Involvement of alveolar bone, much less change of successful repair.

26

What are the 3 primary zones of dental caries?

Surface and body - surface zone remineralizes, body is primary zone of demineralization

Dark zone - zone of increasing demineralization

Translucent zone - leading edge - causes by micro-pores which form in the enamel rod boundaries

27

T/F - Caries are dynamic with continual de-mineralization and re-mineralization, but a net loss.

TRUE

28

What is a dentin bridge?

Dentin formed b/t surviving dentin and restorative material, preventing “micro leakage”

-Biomaterials which induce OD differentiation and dentin production = more rapid dentin bridge

29

What are the 3 key components in tissue engineering?

Cell source

Material

Bioactive component

30

What is reactionary dentin?

What is reparative dentin?

Reactionary - Trauma does NOT damage ODs

Reparative - Trauma DOES damage ODs

Tertiary (sclerotic) dentin formation

31

Cellular and acellular approaches to tooth repair.

Advantages and disadvantages to each

Tissues need cells to regenerate, but many contain cells containing the necessary cells

Cellular
-Addition of material containing cells

Acellular
-Materials to existing tissues