Cell Growth, Fibrosis, Wound Healing

Question 1

general timeline for tissue repair

Answer 1

Inflammation (contain injury and agent)

Repair (2 parts) - regeneration and fibrosis or fibroplasia

Question 2

regneration

Answer 2

recovery of original tissue by cell growth, proliferation, migration, and differentiation

Question 3

labile cells

Answer 3

capable of regeneration - continually dividing cells like surface epithelia

Question 4

stable cells

Answer 4

infrequentnly dividing cells - liver and smooth muscle

Question 5

permanent cells

Answer 5

rarely / non-dividing cells like neurons and skeletal muscle cells

Question 6

gliosis

Answer 6

scaring mechanism in the central nervous system

Question 7

fibrosis/fibroplasia

Answer 7

scaring - last means of repair for a tissue

depends on the regenerative capacity of the tissue or the extend of the injury or defect

Question 8

location of adult stem cells

Answer 8

reside permanently in most organs

Question 9

liver adult stem cells

Answer 9

ovalocytes- in the ducts of Hering

become activated following fulminant hepatic failure and chronic liver disease (process will be slowed)

Question 10

stellate cells

Answer 10

skeletal muscle stem cells which have the ability to regnerate

Question 11

3 mechanisms of regeneration in surface epithelium

Answer 11

1. increase number of dividing stem cells
2. expanding the number of cells in the replicating compartment
3. decreasing replication time

Question 12

healing involves combination of..

Answer 12

regeneration and fibroplasia

Question 13

cardiac insufficiency, portal hypertension and liver failure, chronic respiratory failure, joint disability and deformity can be caused from…

Answer 13

diseases that are complicated by fibroplasia

Question 14

steps in tissue repair

Answer 14

1. inflammation
2. cell proliferation and migration
3. synthesis of extracellular matrix (ECM)
4. Remodeling of ECM

Question 15

mainly responsible for the formation and function of granulation tissue

Answer 15

growth factors

Question 16

angiogenesis from pre-existing vessels

Answer 16

1. degradation of basement membrane
2. migration of endothelial cells
3. proliferation of endothelial cells
4. Maturation and tube formation

Question 17

2 domains in ECM structure and properties

Answer 17

1. Basal Membrane- cells can adhere to and move along - necessary for re-epitheliazation of ulcer
   Consist of non -fibrill collagens, laminin, heparan sulfate, proteoglycan and other glycoproteins
2. Interstitial Matrix- prominent element in connective tissue- fibrill collagen and non-fibrill collagen, elastin, hyaluronate - PROMINANT IN LAYER 3 (ecm formation)

Question 18

3 properties of ECM

Answer 18

1. stuff between cells giving tissues the physical characteristics like tugor, elasticity, rigidity
2. reservoir for molecules like growth factors
3. adherence capbilities for the cells

Question 19

ECM structure -3 elements (macromolecules)

Answer 19

fibrous structural proteins
cell adhesion proteins (CAMs)
Gel of protoeglycans and hyalluronan

Question 20

metalloproteinases

Answer 20

remodelling is achieved by this in a process of degradation of collagen and other ECM proteins by this enzyme

Question 21

inflammation (step 1) associated with what layer?

Answer 21

Layer 1

Necrosis and Acute Inflammatory Exudate

Question 22

Tissue elements and molecular elements in Layer 1 - acute inflammation and necrosis

Answer 22

Tissue: Fibrin, neutrophils, macrophages, platalets

Molecular:
Interleukins, Interferons, Tumor Necrosis Factor
Growth Factors: PDGF FGF

Question 23

myeloperoxidase

Answer 23

Neutrophil granulocytes = secrete the myeloperoxidase - carry out their immune function - enzyme
*this digests cells and and signals the second layer

Question 24

Tissue elements and molecular elements in Layer 2- granulation tissue

Answer 24

Cellular : Capillaries, Fibroblasts, Macrophages 
Molecular Elements
EGF/TGF-alpha
PDGF
FGF
VEGF - angiogenisis
TGF-beta
Angiopoietins

Question 25

Step 2 in tissue repair corresponds with what level in ulcer

Answer 25

step 2 = cell proliferation and migration | Layer 2- the granulation tissue layer

Question 26

Step 3 in tissue repair corresponds with what level in ulcer

Answer 26

Step 3 = synthesis of ECM Layer 3 of the ulcer- granulation tissue AND ECM

Question 27

Step 4 in tissue repair corresponds with what level in ulcer

Answer 27

step 4 = remodeling of ECM and layer 4 in ulcer = fibrosis scar

Question 28

Describe Layer 3- synthesis of extracellular matrix

Answer 28

ECM - 2 domains (basal and interstitial) and 3 elements - fibrous structural proteins, CAMs, and Gel of proteoglycans and hyaluronan

Question 29

granulation tissue

Answer 29

capillaries, fibroblasts, macrophages

Question 30

CAMs

Answer 30

one of the elements of the ECM structure | Cadherins, Integrins, Fibronectin, Laminin

Question 31

Fibrous structural proteins

Answer 31

one of the elements of the ECM structure | Collagens, Elastins

Question 32

ECM functions

Answer 32

Tissue Texture- turgor, elasticity, rigidity Resoivoir - growth factors Substratum matrix- cell adherence and migration

Question 33

events in layer IV

Answer 33

Remodeling of ECM and formation of collagen plates Regression of blood vessels Wound contraction

Question 34

Collagenases, Gelatinases, Stromelysins are all?

Answer 34

Matrix metalloproteinases

Question 35

local factors effecting wound healing

Answer 35

Blood supply, denervation, infection, , foreign body, necrotic tissue, mechanical stress, surgical technique, type of tissue

Question 36

Systemic factors affecting wound healing?

Answer 36

diabetes, malnutrition, steroids, uremia, hypoxia, vitamin C defiency, malignant disease

Question 37

ki67?

Answer 37

marker for surface epithelial proliferation

Question 38

paracrine signaling with FGF

Answer 38

derived from macrophages causing fibroblasts to proliferate into granulation tissue