Tissue Repair and Wound Healing Flashcards Preview

Block 6 > Tissue Repair and Wound Healing > Flashcards

Flashcards in Tissue Repair and Wound Healing Deck (35):
1

Restoration of tissue architecture and function after an injury is called what?

Repair

2

What is the replacement of the damaged cells and essentially return to a normal state? Occurs by ____ of residual or uninsured cells and by _____ from tissue stem cells. Usual response in what?

Regeneration

Residual cells, replacement

Usual response in rapidly dividing epithelia of the skin, intestines, liver

3

What is injured tissues that are incapable of regeneration, or supporting structures of the tissue are severely damaged?

Scar formation- repair occurs by the laying down of CT-->scar formation

Scar cannot perform the function of lost parenchyma cells, but provides structural stability that the injured tissue is usually able to function

4

What is extensive deposition of collagen that occurs as a consequence of chronic inflammation or ischemic necrosis (infarction)?

Fibrosis- if fibrosis develops in a tissue space occupied by an inflammatory exudate, it is called organization (such as PNA in lung)

5

Cell and tissue regeneration involves cell ____ driven by ____ ______ and is critically dependent on the integrity of the _____ ______.

Proliferation
Growth factors
Extracellular matrix

6

There are several types of cells that proliferate during tissue repair. What are they?

-remnants of the injured tissue
-vascular endothelial cells
-fibroblasts

7

Non dividing cells (cell cycle arrest)

G1

8

Exited the cycle (growth factors stimulate cells to transition from this phase to another phase)

G0

G0 to G1 -- S, G2, and M phases

9

What are hematopoietic cells, surface epithelia, and GI tract epithelium?

Labile (continuously dividing) tissues

These readily regenerate after injury as long as the pool of stem cells is preserved

10

What tissues are quiescent and have only minimal replicating activity in their nml state but are capable of proliferating in response to injury or loss of tissue mass?

Stable tissues

Liver, kidney, and pancreas

11

What tissue is terminally differentiated and non-proliferative?

Permanent tissues

Neurons, skeletal muscle, cardiac muscle

Results in a scar

12

What has self-renewal capacity and asymmetric replication?

Stem cells

13

The most undifferentiated stem cells

Embryonic stem cells

Inner cell mass of the blastocyst with extensive cell renewal capacity

14

Tissue stem cells are less undifferentiated and are found among differentiated cells within an organ or tissue with limited self-renewal capacity

Adult stem cells

15

Hematopoietic stem cells can be isolated from ____ _____ and peripheral blood after mobilization by administration of certain cytokines such as G-CSF.

Bone marrow

Can give rise to all blood cell lineages and continuously replenish the formed elements of the blood

Used for treatment of leukemia and lymphomas

16

These are proteins that stimulate the survival and proliferation of particular cells and may also promote migration, differentiation, and other cellular responses.

Growth factors

17

Growth factors induce cell proliferation by binding to specific receptors and affecting the expression of genes whose products typically have what functions?

-Promote entry of cells into the cell cycle
-stimulate the function of growth control genes

18

Signaling may occur directing in the same cell that produces the factor (____ signaling), between adjacent cells (_____ signaling), or over greater distances (______ signaling).

Autocrine
Paracrine
Endocrine

19

What is present in the spaces between cells in CT and between epithelium and supportive vascular and smooth muscle structures?

Interstitial matrix

Synthesized by mesenchymal cells (fibroblasts)

20

What lies beneath the epithelium and is synthesized by overlying epithelium and underlying mesenchymal cells?

Basement membrane

21

Genetic defect in collagen?

Ehlers-Danlos
Osteogenesis imperfecta

22

Defect in Elastin?

Marfan syndrome - skeletal abnormalities and weak ended aortic walls

23

What are hydrated compressible gels conferring resilience and lubrication?

Proteoglycans

24

What are important constituents of the ECM that binds water?

Hyaluronan

25

What is involved in cell-to-cell adhesion with linkage of cells to ECM and binding between ECM components?

Adhesive glycoproteins and adhesion receptors
-includes fibronectin (interstitial ECM) and laminitin (basement membrane)

26

ECM provides mechanical support for cell _____ and cell ______, and maintenance of cell _____. Control of cell _____ by binding and displaying growth factors. Scaffolding for tissue _____.

Anchorage
Migration
Polarity
Proliferation
Renewal

27

What are the steps in scar formation? (3)

1. Formation of new blood vessels (angiogenesis)
2. Migration and proliferation of fibroblasts and deposition of CT called granulation tissue
3. Maturation and reorganization of fibrous tissue (remodeling) to produce stable fibrous scar

28

Repair beings within ____ hours of injury by the emigration of ____ and the induction of ____ and endothelial cell proliferation.

24
Fibroblasts
Fibroblasts

29

After ___ to ____ days specialized granulation tissue will appear. Scar remodel will occur over time.

3 to 5 days

30

What is the most important cause for delay in healing?

Infection

31

What are the factors that influence tissue repair? (6)

-infection
-nutrition
-glucocorticoids (steroids)
-mechanical variables (increased local pressure or torsion causing wound to pull apart called dehisce)
-poor perfusion (arteriosclerosis and diabetes, obstructed venous drainage)
-foreign bodies (steel, glass, bone)

32

What is an aberration of cell growth where there is accumulation of exuberant amounts of collagen that can give rise to prominent raised scars?

Keloid- more common in Africa-Americans

33

Healing wounds may generate exuberant granulation tissue called what?

"Proud flesh"- restoration of epithelial continuity requires cautery or surgical resection of the granulation tissue

34

Clean,, uninflected surgical incision approximated by surgical sutures.

Healing by first intention

35

Cell or tissue loss is more extensive at sites of abscess formation, ulceration, and ischemic necrosis in parenchymal organs.

Healing by second intention