Repair

Question 1

Refers to the restoration of tissue architecture and function after an
injury.

Answer 1

Repair

Question 2

Repair It occurs by two types of reactions

Answer 2

1. Regeneration

2. Healing

Question 3

Refers to tissues are able to replace the damaged components and
essentially return to a normal state.

Answer 3

Regeneration

Question 4

Refers to When repair occurs by laying down of connective (fibrous) tissue,
which results in scar formation.

Answer 4

Healing

Question 5

Continuously dividing tissue.
Lost cell replaced by maturation from stem cells and by
proliferation of mature cells

Answer 5

1.Labile tissues

Question 6

Cells of these tissues have only minimal replicative activity .
These cells are capable of proliferating in response to injury or
loss of tissue mass .

Answer 6

2.Stable Tissues:

Question 7

Terminally differentiated and nonproliferative in postnatal
life.

Answer 7

3.Permanent Tissues:

Question 8

1.Labile tissues examples ?

Answer 8

hematopoietic cells in the bone

marrow and surface epithelia.

Question 9

2.Stable Tissues eg?

Answer 9

liver, kidney, and pancreas, fibroblasts, and smooth muscle

cells.

Question 10

3.Permanent Tissues eg?

Answer 10

neurons and cardiac muscle cells .

Question 11

The sequence of events that control cell proliferation known as
?

Answer 11

Cell cycle

Question 12

proliferation of cells involve two processes: ?

Answer 12

1. DNA replication. 2. Mitosis.

Question 13

The cycle consists of ?

Answer 13

1.The pre-synthetic growth phase 1 (G1), 2. The DNA synthesis phase (S), 3. The pre-mitotic growth phase 2 (G2), 4. The mitotic phase (M ).

Question 14

Which cells are arrest in G1 or they exit the cycle
and enter a phase called G 0.
?

Answer 14

Non-dividing cells

Question 15

Prevent DNA replication or mitosis of damaged cells and allow for
DNA repair. ?

Answer 15

Checkpoint controls:

Question 16

If repair does not occur the damaged cells eliminate by ?

Answer 16

apoptosis

Question 17

Repair by connective tissue deposition consists of ?

Answer 17

1.Formation of new blood vessels (angiogenesis) 2.Migration and proliferation of fibroblasts 3.Deposition of ECM (scar formation) 4.Maturation and reorganization of the fibrous tissue
(remodeling)

Question 18

Scar Formation): It occurs in two steps which are ?

Answer 18

1) Migration and proliferation of fibroblasts into the site of injury (2) Deposition of ECM by these cells.

Question 19

The recruitment and stimulation of fibroblasts is driven by ?

Answer 19

growth factors.

Question 20

Is the outcome of the repair process, it is a balance between
ECM synthesis and degradation.

Answer 20

Tissue Remodeling

Question 21

Growth factors produced by ?

Answer 21

Leukocytes • Parenchymal cells . • The stromal (connective tissue)

Question 22

Sequence of repair by connective tissue ?

Answer 22

1. Emigration of fibroblasts and induction of fibroblasts and endothelial cells proliferation
2. Granulation tissue begins ( proliferating fibroblasts newly formed thin capillaries and loose ECM

Question 23

What happens if the tissue injury is too severe and regeneration is not possible ?

Answer 23

Scar formation :
Replacement of injured tissues ( dead cells ) with connective tissue ( heavy deposition of collagen ) = lfibrosis or scar formation

Question 24

Scar formation :
Replacing necrotic tissues with connective tissue leading to scar formation or by thr combination of regeneration of some cells and scar formation

In which types of situations?

Answer 24

1. Non dividing cell injury
2. ECM stromatolites cells injury
3. after chronic inflammation response
4. Ostensively ischemic necrosis ( myocardium infarction )

Question 25

Fibrosis replacing purple trim exudates ?

Answer 25

Organization

Question 26

Which type of healing occurs in a clean wound ? And what are the other properties?

Answer 26

Healing by primary intention | No tissue loss / no infection / good blood supply

Question 27

Which type of healing is caused by infection ? And what are the other properties ?

Answer 27

Healing by secondary intention | Excessive trauma / tissue loss / imprecise approximation of tissue

Question 28

End result of healing primary ?

Answer 28

``` Rapid healing and epitheliazation less granulation tissue Less fibrosis Minimal scar Epithelial regeneration predominate over fibrosis ```

Question 29

End result of healing secondary | ?

Answer 29

Slower / more inflammation and granulation tissue formation and more scaring

Question 30

Example or secondary healing ?

Answer 30

Large burns and ulcer / pressure sore / infarction

Question 31

The main bulk od secondary healing is ?

Answer 31

Granulation tissue

Question 32

Granulation tissue is formed by proliferation of?

Answer 32

Fibroblasts and neovascularization

Question 33

Important feature of wound healing second ?

Answer 33

Contraction of wound

Question 34

More collagen ?

Answer 34

Gives scar

Question 35

Diff of prim and sec healing ?

Answer 35

Second : more inflammation / more granu tissue / wound contraction

Question 36

Wound contraction ?

Answer 36

Dec. wound size / myofibroblast / cell fish gran tissue to cell pops scar tissue

Question 37

Factors affect healing ?

Answer 37

1.Infections and diabetes. 2.Nutrition , protein deficiency, vitamin C deficiency, inhibits collagen synthesis and retards healing. 3.Glucocorticoids (steroids) result in poor wound strength due to diminished fibrosis. 4.Mechanical variables such as increased local pressure or torsion. 5. Poor perfusion 6. Foreign bodies such as fragments of glass, or even bone impede healing. 7.The type (and volume) of tissue injured is critical.

Question 38

excessive scars composed of irregularly deposite thick hyalinized collagen bands. They may appear as bulging masses are?>

Answer 38

Keloids

Question 39

result of an overgrowth | of dense fibrous tissue?

Answer 39

Keloids

Question 40

``` tissue extends beyond the borders of the original wound, does not usually regress spontaneously, and tends to recur after excision. ? ```

Answer 40

Keloids

Question 41

characterized by erythematous, pruritic, raised fibrous lesions ?

Answer 41

hypertrophic

Question 42

do not expand beyond the boundaries of the initial injury and may undergo partial spontaneous resolution?

Answer 42

hypertrophic

Question 43

develops after healing of a skin injury. | ?

Answer 43

Keloids

Question 44

common after thermal injuries. ?

Answer 44

Hypertrophic

Question 45

HEALING OF BONE FRACTURE ?

Answer 45

A. Bleeding stage and formation of procallus. B. Endochondral ossification. C. Formation of bony callus.

Question 46

Rupture of blood vessels results in a hematoma, which : ?

Answer 46

fills the fracture gap and B- surrounds the area of bone injury.

Question 47

The clotted blood provides a fibrin mesh, which ?

Answer 47

helps seal off the fracture site and at the same time B- creates a framework for the influx of inflammatory cells and ingrowth of fibroblasts and new capillary vessels

Question 48

Which cells release : • PDGF, • TGF-β, • FGF, and • Interleukins?

Answer 48

degranulated platelets and migrating inflammatory

Question 49

activate the osteoprogenitor cells which stimulate ?

Answer 49

osteoclastic and osteoblastic activity

Question 50

fusiform and predominantly uncalcified tissue is called?

Answer 50

soft- tissue callus or procallus

Question 51

The activated osteoprogenitor cells deposit?

Answer 51

subperiosteal trabeculae | of woven bone within the medullary cavity.

Question 52

activated mesenchymal cells in the soft tissues and bone surrounding the fracture line also differentiate into ?

Answer 52

chondroblasts that make fibrocartilage and hyaline cartilage

Question 53

ossification, the fractured ends are bridged by?

Answer 53

bony | callus.

Question 54

restores the original size and shape of the bone, ?

Answer 54

callus remodeling

Question 55

Factors affecting bone healing?

Answer 55

1- Displaced and comminuted fractures frequently result in some deformity; 2- Inadequate immobilization 3- Infection 4- others: Bone repair will obviously be impaired by • Inadequate levels of calcium or phosphorus • Vitamin deficiencies, • Systemic infection, • Diabetes, and • Vascular insufficiency