Regeneration and repair Flashcards Preview

**Oral Biology > Regeneration and repair > Flashcards

Flashcards in Regeneration and repair Deck (53):
1

What are the 4 phases of tissue repair?

1. Hemostasis
2. Inflammatory
3. Reparative (proliferative)
4. Wound contraction and scarring (not always)

2

What is Hemostasis?

Clot formation

3

What is involved in the inflammatory step of tissue repair?

Infiltration of immune cells, initiation of repair

4

What is involved in the reparative phase of tissue regeneration?

Migration of cells, Formation of granulation tissue

5

What phase of tissue repair involves the transition of blood from a liquid to a fibrillar gel?

Hemostasis

6

What is the primary goal of hemostasis?

Stop the bleeding

7

What is the secondary goal of hemostasis?

Initiation of healing

8

What leads to the coagulation cascade?

Disruption of platelets

9

In hemostasis the _____ unites the edges of wound, and ________ provides a scaffold for future cell migration and repair

1. Clot
2. Fibrin

10

How is a clot in the oral cavity different than the rest of the body?

Softer, more easily detached

11

What type of Hemostasis is described as the "Platelet Plug"?

Primary

12

Vascular spasm (constriction) and initial platelet plug in a damaged blood vessel happens in which type of hemostasis?

Primary

13

In primary Hemostasis, initiation of it occurs by exposure of collagen in _______ to circulating _______ factor

1. Subendothelium
2. Von Willebrand factor

14

What does Von Willebrand factor do?

Causes platelet aggregation by interacting with platelet surface proteins

15

What receptor complex is associated with the function of von Willebrand factor?

GP1b-IX-V

16

How would platelets bind collagen directly?

via GPVI (Glycoprotein VI) and a2B1 integrin

17

In Primary hemostasis, Platelets activate and dump out tons of preformed cytoplasmic vesicles containing more _____, _____, and _______, and _____

1. vWF
2. Fibrinogen
3. Coagulation factors V and XIII
4. Platelet agonists serotonin and ADP

18

What anchors platelets together?

Fibrinogen

19

When does Secondary Hemostasis happen?

Simultaneously with or just after primary hemostasis

20

What is the main feature of secondary hemostasis?

Blood coagulation

21

T/F The cascade of Secondary hemostasis is a very simple one

False, it is fairly complex

22

What are the two pathways of secondary hemostasis?

1. Extrinsic
2. Intrinsic

23

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

24

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)

25

The main point of hemostasisis the conversion of ______ into ______

1. Prothrombin
2. Thrombin

26

What does thrombin do?

Converts soluble fibrinogen into insoluble fibrin

27

Many of the steps in clotting require what?

Calcium

28

How does fibrin form a blood clot?

Cross-links and form a mesh, trapping red an white cells, resulting in blood clot

29

What are the first cells on the scene in an inflammatory response?

Neutrophils

30

How are neutrophils activated?

Antibody-antigen interactions, LPS, complement system

31

What cells arrive second in inflammation?

Macrophages

32

What phase of tissue repair involves cell migration under fibrin clot and creates a highly cellular granulation tissue?

Reparative/Proliferative

*Mobilization of adjacent cells

33

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

34

In reparative phase, ____ recruitment occurs, with proliferation of _______ in the wound

1. fibroblast
2. fibroblast

35

The fibroblasts recruited to the wound are both resident and new ones from mesenchymal progenitor cells T/F

True

36

In what phase do we get Endothelial cell proliferation andangiogenesis and what factors are involved in this?

1. Reparative/Proliferative
2. TGFB, VEGF, FGF-2

37

What are the specialized fibroblasts involved in wound crontraction?

Myofibroblasts

*increased actin/myosin

38

How do myofibroblastsperform wound contraction?

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

39

T/F the initial collagen deposis by fibroblasts is very mobile.

False, immobile scar tissue and can be remodeled

40

T/F Generally there is no scarring of the oral mucosa

True

41

What can arrest the spread of infection into periodontal tissues?

Fibrosis

42

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

43

Repair mechanism of PDL is broadly the same as in what organ?

Skin

44

What is different in PDL repair as opposed to skin repair?

Immediate remodeling of collagen by ligament fibroblasts = no scar

45

What can we add to PDL repair to encourage ligament reattachment?

Growth factors

46

What are the 3 primary zones in Dental Caries?

1. Surface and Body
2. Dark Zone
3. Translucent Zone

47

Describe the surface and body zone in dental caries?

Surface zone re-mineralizes, body is the primary zone of demineralization

48

Describe the dark zone of dental caries

Zone of increasing demineralization

49

Describe the transluscent zone of dental caries

Leading edge, caused by micro-pores which form in the enamel rod boundaries

50

How are caries dynamic?

Continual de-mineralization and re-mineralization, but a net loss

51

What are the 3 key components of Tissue Engineering?

1. Cell source
2. Material
3. Bioactive Component

52

Define Bioactive materials

Materials which are designed to drive repair/regeneration through the use of bioactive factors

53

T/F even after damage the pulp remains partially vital which leaves a reservoir of tissue to work with

True