Healing and repair

Question 1

What are the four stages of healing?

Answer 1

Clotting Phase
Inflammation Phase
Proliferative phase
Maturation Phase

Question 2

What are labile cells?

Answer 2

Allow rapid regeneration for cell repair

Question 3

What are stable cells?

Answer 3

Have variable states of regeneration, rapid proliferation in response to injury

Question 4

What are permanent cells?

Answer 4

Unable to divide and regenerate

Question 5

What is an example of permanent cells in oral cavity?

Answer 5

Nerve fibres

Question 6

What is an example of labile cells in the oral cavity?

Answer 6

Oral keratinocytes

Question 7

What is an example of stable cells in the oral cavity?

Answer 7

Oral fibroblasts

Question 8

STAGES IN HEALING

Question 9

What is formed during the proliferative phase?

Answer 9

Granulation tissue

Question 10

What makes up new tissue during the proliferative phase?

Answer 10

Fibroblasts

Question 11

What is meant by angiogenesis?

Answer 11

The formation of new blood vessels

Question 12

What else, other than fibroblasts, is essential in the formation of granulation tissue?

Answer 12

Growth factors

Question 13

What is involved during the first phase of forming granulation tissue?

Answer 13

Mix of proliferating capillaries, fibroblasts and immune cells
These capillaries are very leaky allowing cells and fluid into tissue

Question 14

What does the second phase of the formation of the granulation tissue involve?

Answer 14

Mature fibroblasts lay down collagen

Question 15

What is the growth factor produced by innate immune cells?

Answer 15

Vascular endothelial growth factor (VEGF)

Question 16

What are the two mechanisms of angiogenesis?

Answer 16

Sprouting
Intussusceptive (splitting)

Question 17

What are functions of growth factors?

Answer 17

-Promote cell survival
-Angiogenesis
-Locomotion
-Contractility

Question 18

What is fibrosis?

Answer 18

The deposition of collagen to form of fibrous connective tissue

Question 19

What is fibrosis driven by?

Answer 19

Fibroblasts and macrophages

Question 20

What macrophage subtypes control fibroblast function during fibrosis?

Answer 20

M1 and M2

Question 21

What growth factors do M2 macrophages produce?

Answer 21

Transforming growth factor BETA (TGFB)
Platelet derived growth factor (PDGF)

Question 22

What occurs during the maturation phase?

Answer 22

Tissue remodelling

Question 23

How much of pre injury strength is regained during the maturation phase?

Answer 23

80%

Question 24

What are the three stages of fracture healing?

Answer 24

Inflammatory stage
Repairing stage
Remodelling phase

Question 25

What happens during the inflammatory stage in fracture healing?

Answer 25

A hematoma is formed, bone cells are completely derived of oxygen and blood and die

Question 26

What is a hematoma?

Answer 26

Blood clot formation in hard tissue

Question 27

What happens during stage 1 of the repairing stage in fracture healing?

Answer 27

Capillaries form into the hematoma Fibroblasts produce collagen Osteoblasts form spongy bone Granulation tissue is formed and becomes fibrocartilage callus

Question 28

What happens during stage 2 of the repairing stage in fracture healing?

Answer 28

Chondrocytes and osteoblasts produce cartilage and bone Granulation tissue is ossified Formation of hard bone callus (woven bone)

Question 29

What happens during the remodelling stage during fractured healing?

Answer 29

Osteoclasts and osteoblasts remodel the hard bone callus Cortical bone replaces woven bone Angiogenesis is essential