Tissue Repair

Question 1

Chronic inflammation heals how?

Answer 1

Fibrosis.

Question 2

How is Regeneration of stable tissue achieved?

Answer 2

Compensatory growth.

Question 3

How is Regeneration of renewing tissue achieved?

Answer 3

Regrowing.

Question 4

What leads to commitment of stem cells to differentiate into specific cells?

Answer 4

Activation of key regulatory proteins by growth factors and cytokines.

Question 5

What does the Transduciton systems require to function?

Answer 5

Cell-surface receptors

Question 6

Transduction system that has tyrosine kinase receptors bind to what?

Answer 6

Growth factor.

Question 7

What happens when growth factor binds to a tyrosine kinase receptor?

Answer 7

Dimerization and autophosphorylation of tyrosine residue.

Question 8

With a partial hepatectomy what happens during DNA replication?

Answer 8

incorporation of tritiated thymidine.

Question 9

What does an activated RAS from a bridging potein activate?

Answer 9

RAF or MAP kinase kinase kinase

Question 10

What does RAF phophorylate?

Answer 10

MEK or MAP kinase kinase

Question 11

What does MEK phosphrylate?

Answer 11

ERK or Map Kinase

Question 12

What does ERK phosphorylate?

Answer 12

Cytoplasmic proteins and nuclear transcription factors

Question 13

With a partial hepatectomy what happens during DNA replication?

Answer 13

incorporation of tritiated thymidine.

Question 14

What happens with a partial hepatectomy?

Answer 14

Remaining part enlarges. The missing part is not replaced.

Question 15

What are the 3 stages of activating something to undergo enlargment?

Answer 15

1. Priming.
2. Proliferation.
3. Growth inhibition.

Question 16

What signals the priming stage of tissue regeneration?

Answer 16

Cytokines: TNF, IL-6, others ( to cause the cells to enter the cell cycle.)

Question 17

What will activate the proliferation stage of tissue regeneration?

Answer 17

Growth factors: HGF, TGF-alpha, others. (to make the cells progress through the cell cycle and undergo DNA replication)

Question 18

What will inhibit growth?

Answer 18

TGF-Beta, Activin, others.

Question 19

What are the adjuvants (helpers) of the proliferation phase?

Answer 19

Norepinephrine, insulin, thyroid hormone, growth hormone.

Question 20

What are the major components of the ECM?

Answer 20

Collagen, proteoglycans, and adhesive glycoproteins.

Question 21

What vitamin is needed for HO-ization?

Answer 21

Ascorbic acid. (Vitamin C)

Question 22

What is fibronectin?

Answer 22

2 glycoprotein chains held by disulfide bonds.

Question 23

What binds ECM components and interacts with the cytoskeleton at focal adhesions complexes?

Answer 23

Integrin.

Question 24

What induces Angiogenesis from the bone marrow and pre-existing vessels?

Answer 24

Mobilization of the Endothelial precursor cells (EPC)

Question 25

EPC's from the bone marrow migrate to where?

Answer 25

Site of injury or tumor growth.

Question 26

What do EPC's do at sites of injury?

Answer 26

They differentiate and form a mature network of vessels.

Question 27

What are MMP's?

Answer 27

Matrix metalloproteinase. They help degrade collagen and other ECM proteins.

Question 28

MMP's are dependent on what mineral?

Answer 28

Zinc.

Question 29

What are the 4 mechanisms of MMP regulation?

Answer 29

1. regulation of synthesis by growth factors or cytokines. 2. Inhibition of synthsis by corticosteroids or TGF-beta. 3. secreted in inactive form. 4. Blockage of the enzymes by specific tissue inhibitors of metalloproteinase.

Question 30

The inflammation phase of wound healing lasts how long?

Answer 30

3 days.

Question 31

The granulation tissue phase of the healing process takes place when?

Answer 31

0.3 days until 10 days.

Question 32

The wound contraction phase of the healing process takes place when?

Answer 32

3 days to 30 days.

Question 33

What will clean up an injured site after the healing process?

Answer 33

Macrophages.

Question 34

What type of scaring occurs with primary intention healing?

Answer 34

Minimal scarring

Question 35

What type of scaring occurs with secondary intention healing?

Answer 35

Broader scar result of granulation

Question 36

What type of scaring occurs with tertiary intention healing?

Answer 36

Wound is purposely left open

Question 37

What type of injury is primary intention healing?

Answer 37

Little tissue loss.

Question 38

Most surgical wounds heal by which intention?

Answer 38

Primary intention healing. (wound edges are directly next to each other)

Question 39

How is a primary intention wound is closed?

Answer 39

By sutures, staples or adhesive.

Question 40

What is allowed to happen to the wound with secondary intention healing?

Answer 40

It is allowed to granulate.

Question 41

Why can the healing process be slower with secondary intention healing?

Answer 41

Due to the presence of drainage from infection and surgeons may pack the wound with gauze or use a drainage system.

Question 42

How long will a tertiary intention scar be left open?

Answer 42

4-5 days.(where the wound is initially cleaned, debrided and observed before closure)

Question 43

What is Keloid?

Answer 43

Excess collagen deposition in the skin forming a raised scar.

Question 44

What does stimulus from chronic inflammation activate?

Answer 44

Macrophages and lymphocytes.

Question 45

What do Activated macrohages and lymphocytes in chronic inflammation areas do?

Answer 45

Production of growth factors, cytokines.

Question 46

What do Growth factors cytokines in a chronic inflammation areas do?

Answer 46

Increased collagen synthesis.

Question 47

What does Increased collagen synthesis in a chronic inflammation areas do?

Answer 47

Fibrosis.

Question 48

What do Activated macrophages and lymphocytes in chronic inflammation do to MMP's?

Answer 48

They decrease their activity.

Question 49

What happens in chronic inflammation when MMP's have decreased activities?

Answer 49

IT will decrease the collagen degradation.

Question 50

When collagen is not degraded or is allowed to be synthesised in chronic inflammation what happens?

Answer 50

Fibrosis.

Question 51

What happens with an injury when the stimulus that caused the acute injury is removed?

Answer 51

Parenchymal cell death.

Question 52

What does Parenchymal cell death with deep wounds leads to?

Answer 52

Healing- scar formation organization of exudate.

Question 53

What does Parenchymal cell death within superficial wounds leads to?

Answer 53

Regeneration and restitution of normal sturcture

Question 54

What does persistent tissue damage lead to?

Answer 54

Fibrosis (tissue scar)