Tissue Repair

Question 1

regeneration (and scar formation) occurs where

Answer 1

• occurs with injured tissue and vascular endothelial cells

Question 2

fibroblasts functions

Answer 2

• supply fibrous tissue for scar
• produces growth factors
• responsible for extracellular matrix (ECM)

Question 3

3 proliferative capacities of tissues

Answer 3

labile, stable, and permanent tissues

Question 4

labile tissues capacity and types

Answer 4

• continuously divide
• hematopoietic stem cells and surface epithelial cells

Question 5

stable tissues capacity and types

Answer 5

• minimal replicative abilities
• parenchyma (tissue) of liver, kidney pancreas and endothelial cells, fibroblasts, and smooth muscle cells

Question 6

permanent tissues capacity and types

Answer 6

• nonproliferative
• neurons and cardiac muscle cells, some skeletal muscle cells
• scarring in this tissue

Question 7

growth factors for regeneration are what

Answer 7

• are proteins that promote cell proliferation via binding to specific cellular receptors, and promoting expression of gene products

Question 8

what are growth factors involved with and what can be bad?

Answer 8

• involved with growth control genes termed oncogenes
• oncogene mutations, which can lead to cancer due to uncontrolled cell proliferation

Question 9

VEGF (vascular endothelial growth factor) source and functions

Answer 9

• source: mesenchymal cells
• functions: stimulates proliferation of endothelial cells, increases vascular permeability, and angiogenesis

Question 10

anti-VEGF intravitreal injection names

Answer 10

Avastin, Lucentis, Eylea, Beovu Vabysmo

Question 11

anti-VEGF intravitreal injection treats what

Answer 11

treats many neovascular and edematous ocular retinal conditions
- examples: AMD, diabetic macular edema, PDR (proliferative diabetic retinopathy)
ALSO treats some tumors

Question 12

ECM (extracellular matrix) functions

Answer 12

mechanical support, control of cell proliferation, scaffolding for tissue renewal, and establishment of tissue microenvironments

Question 13

ECM components

Answer 13

• collagen and elastin: fibrous structural proteins (strength and recoil)
• proteoglycans and hyaluronan: resilience and lubrication
• glycoproteins: adhesion of cell and ECM components

Question 14

collagen in ECM

Answer 14

• depends on vit C to function
• genetic defect associated with Ehlers-Danlos syndrome

Question 15

Elastin in ECM

Answer 15

• functions w/ fibrillin glycoproteins to provide elasticity
• associated w/ marfan syndrome due to fibrillin synthesis defect

Question 16

Process of scar formation

Answer 16

1. inflammatory response
2. angiogenesis (formation of new blood vessels)
3. formation of granulation tissue (fibroblasts, CT, vessels, and leukocytes)
4. scar from CT and collagen

Question 17

angiogenesis vs neovascularization

Answer 17

angiogenesis: good new blood vessel regeneration
neovascularization: bad/leaky new blood vessel regeneration

Question 18

2 examples of neovascularization of the eye

Answer 18

1. neovascularization of the disc
2. subretinal hemorrhage (wet AMD)

Question 19

angiogenesis and ECM

Answer 19

ECM proteins participate in angiogenesis, MMP degrade ECM to make room for new vessels

Question 20

fibroblast and CT roles in scar formation

Answer 20

• are recruited to injury site
• proliferate
• make and deposit ECM proteins

Question 21

factors that modify wound healing

Answer 21

1. infection
2. nutrition (protein and Vit C deficiencies)
3. steroids, prevent healing
4. poor perfusion, especially in DM and arteriolosclerosis

Question 22

Fibrosis definition

Answer 22

Extensive deposition of collagen when tissue is incapable of regenerating