Healing/Repair

Question 1

Labile tissues

Answer 1

Hematopoietic cells of bone marrow
Squamous epithelium of skin, oral cavity, cervix, vagina
Columnar epithelium of GI tract

Cells that continuously divide

Question 2

Stable tissues

Answer 2

Kidney
Liver
Smooth muscle

Low to no replication(G0), but can enter G1 and replicate rapidly if required

Question 3

Permanent tissues

Answer 3

Heart, neural tissue, skeletal muscle

Cells that don’t divide

Question 4

Epidermal Growth Factor - what does it do?

Answer 4

Stimulates fibroblasts and keratinocytes to divide. Stimulates keratinocytes to migrate

Question 5

TGFa - what does it do?

Answer 5

Stimulates proiferation of hepatocytes and other epithelial cells

Question 6

VEGF - what does it do?

Answer 6

Endothelial cells

Angiogenesis, increased permeability

Question 7

PDGF - what does it do?

Answer 7

Chemotactic, stimulates ECM protein synthesis

Question 8

FGFs - what does it do?

Answer 8

Chemotactic, mitogenic for fibroblasts

Question 9

TGFb- and what does it do?

Answer 9

Chemotactic for leukocytes, suppresses acute inflammation

Question 10

Give two reasons why a scar would form

Answer 10

The injured tissue doesn’t reproduce (muscle, not neurons)

Question 11

Which 3 nutrients are associated with improved wound healing?

Answer 11

Vitamin C
Copper
Zinc

Question 12

What is the von Hippel Lindau gene, and how does it relate to VEGF?

Answer 12

It is a tumor suppressor gene that binds the transcription factor HIF1a, limiting VEGF expression. This checks angiogenesis.

Question 13

How does von Hippel Lindau syndrome affect VEGF expression?

Answer 13

HIF1a is constitutively activated. Unchecked VEGF expression. This leads to more angiogenesis in the pigment epithelium of the eye as well as the kidney.

Question 14

Which type of collagen is found in granulation tissue?

Answer 14

Collagen III

Question 15

Which type of collagen is found in scar tissue?

Answer 15

Collagen I

Question 16

When does cell repair happen in relation to inflammation?

Answer 16

Cell repair is initiated when cell repair begins

Question 17

How do glucocorticoids affect wound healing?

Answer 17

Glucocorticoids are anti-inflammatory and inhibit TGF-beta production

Question 18

How does diabetes mellitus affect would healing?

Answer 18

DM can result in a poor vasculature, nutrition and immune system

Question 19

What aspects make up granulation tissue?

Answer 19

1. Proliferation fibroblasts laying down type III collagen

2. Proliferating new blood vessels

Question 20

What does the migration and proliferation of fibroblasts require?

Answer 20

1. Fibroblasts synthesize CT proteins

2. Recruitment and activation driven by many growth factors (PDGF, FGF, TGF-beta)