Repair

Question 1

repair

Answer 1

process by which lost or necrotic cells are replaced by vital cells

Question 2

2 processes of repair

Answer 2

regeneration and scarring/fibrosis

Question 3

regeneration

Answer 3

replacement by cells of the same type

Question 4

scarring or fibrosis

Answer 4

replacement by connective tissue

Question 5

what factors favor fibrosis over regeneration?

Answer 5

• severe/prolonged injury
• loss of BM
• large amts. of exudate
• lack of renewable cells

Question 6

labile cell

Answer 6

cell that multiplies constantly. Ex: epidermis, hematopoietic cells, lymphoid cells. DO NOT enter G0 state

Question 7

stable cell

Answer 7

cell that multiplies only when necessary.

Ex: epithelium in lung, liver, kidney, endocrine glands. Endothelial cells, fibroblasts, smooth m.

Question 8

granulation tissue zones from top to bottom

Answer 8

1) necrotic debris/fibrin
2) macs and ingrowing capillaries
3) proliferating capillaries and fibroblasts
4) maturing fibrous CT

Question 9

healing by 1st vs. 2nd intention

Answer 9

2nd intention involves granulation tissue

Question 10

capacity of a tissue to regenerate is determined by what cell cycle stage?

Answer 10

GO (quiescent stage)

Question 11

phases of cell cycle

Answer 11

GO (quiescent) –> G1 (pre-synthetic) –> S (DNA synthesis) –> G2 (pre-mitotic) –> M (mitosis)

From mitosis, cells either terminally differentiate or undergo stable differentiation in which they can enter back into cell cycle if needed

Question 12

What stimulates GO to go back into G1 phase?

Answer 12

• cytokines, growth factors
• loss of contact
• injury-induced mechs.

Question 13

ex. of non-dividing cells

Answer 13

• cardiac myocytes

- neurons

Question 14

stem cells in intestine

Answer 14

crypt stem cells

Question 15

stem cells in liver

Answer 15

oval cells

Question 16

stem cells in cornea

Answer 16

corneal stem cells

Question 17

stem cells in skin

Answer 17

hair follicle bulge stem cells and interfollicular epidermal stem cells

Question 18

embryonic ectoderm gives rise to:

Answer 18

keratinocyte precursors, neurons, oligodendrocytes, ependymal cells

Question 19

embryonic endoderm gives rise to:

Answer 19

epithelial cells of liver, lungs, GI tract

Question 20

embryonic mesoderm gives rise to:

Answer 20

myocytes, osteoblasts, chondrocytes, adipocytes, endothelial cells, bone marrow cells, RBCs

Question 21

BM can serve as stem cells for ciliated cells in resp. airway

Answer 21

:)

Question 22

stages of epithelial regeneration in resp. airway following injury/damage and necrosis

Answer 22

1) rxn of vascularized living tissue
2) inflamm. and removal of debris
3) regen. of epithelium (dedifferentiation, mitosis, migration)
4) redifferentiation, resolution of inflammation
5) completion of regeneration

Question 23

fibrinous

Answer 23

exudate composed of fibrin

Question 24

fibrous connective tissue refers to

Answer 24

collagenous connective tissue

Question 25

Clicker: Which tissues are highly susceptible to repair by fibrosis or scarring because they lack dividing renewable cell populations?**

Answer 25

myocardial myocytes and cerebral cortical neurons

Question 26

how do macs remove injured tissue and debris?

Answer 26

phagocytosis, collagenase, elastase

Question 27

what factors contribute to mac's antimicrobial activity?

Answer 27

NO, ROS

Question 28

what factors stimulate angiogenesis?***

Answer 28

VEGF, FGF, PDGF | "FPV"

Question 29

what factors control macs deposition and remodeling of ECM?

Answer 29

TGF-beta, PDGF, TNF, IL-1, collagenase, MMP's

Question 30

what factors promote monocyte/macrophage chemotaxis?***

Answer 30

``` chemokines PDGF FGF TGF-beta TNF "CFPTT" ```

Question 31

what factors promote fibroblast migration/replication and collagen synthesis?*

Answer 31

``` PDGF EGF FGF TGY-beta TNF IL-1 "EFIPTT" ```

Question 32

what factors promote epithelial proliferation/migration?*

Answer 32

EGF HGF KGF "EHK"

Question 33

what factors promote connective tissue myofibroblast contraction and remodeling?*

Answer 33

``` Collagenase MMP's PDGF TGF-beta "CMPT" ```

Question 34

what does EGF promote?

Answer 34

(epidermal growth factor) promotes epidermal growth

Question 35

what does PDGF promote

Answer 35

(platelet-derived growth factor) - promotes angiogenesis and fibrosis - increases chemotaxis - increases wound contraction - mitogenic - released by many cells

Question 36

effects of TNF-alpha

Answer 36

(tumor necrosis factor) - activate macs - inc. fibroblast proliferation and synthesis of collagen

Question 37

effects of TGF-beta

Answer 37

(transforming growth factor) | -promotes fibrosis

Question 38

effects of FGF

Answer 38

(fibroblast growth factor) - promotes fibrosis and angiogenesis - released by many cells

Question 39

VEGF

Answer 39

(vascular endothelial growth factor) | potent inducer of angiogenesis

Question 40

Which of the following are potent inducers of angiogenesis? VEGF, B-FGF, HGF, or combination***

Answer 40

VEGF and B-FGF

Question 41

common neutrophil chemotactic organism

Answer 41

Trueperella

Question 42

mechs. of tissue injury in inflammation

Answer 42

1) leukocyte mediated damage w/o abnormal immune response | 2) immune mediated damage due to hypersensitivity or autoimmune mechs (include allergic and autoimmune diseases)

Question 43

allergic (hypersensitivity) disease

Answer 43

dz mediated by Ab or cells directed at EXTRINSIC Ag

Question 44

autoimmune dz

Answer 44

dz mediated by Ab or cells directed at INTRINSIC Ag

Question 45

Ex. of Type I hypersensitivity

Answer 45

``` ANAPHYLAXIS allergic dermatitis drug rxn parasite feline asthma COPD in horses ```

Question 46

What do granules of neuts, mac, eos contain?

Answer 46

``` proteases phospholipases defensins cationic peptides major basic protein (eos) ```

Question 47

examples of Type III hypersensitivity**

Answer 47

(IMMUNE COMPLEX TYPE) - immune complex vasculitis/arteritis - immune complex glomerulonephritis

Question 48

immune complex diseases in dogs/cats that result in vasculitis or glomerulonephritis

Answer 48

Dogs: - hepatitis - pyometra - lupus - heartworm - Lyme dz Cats: -Peritonitis, leukemia virus

Question 49

immune complex diseases in horse/cow/pig that result in vasculitis or glomerulonephritis

Answer 49

Horse: - infectious anemia - Strep. equi Cow: diarrhea virus Pig: swine fever, cholera

Question 50

Phases of Type III hypersensitivity rxn

Answer 50

1) immune complex (Ag-Ab) form. in Ag excess 2) immune complex deposition - leukocytes interact with complexes and activated complement - leukocytes release mediators (vasoactive amines, leukotrienes, PAF) - incr. permeability of endothelial cells 3) immune complex-mediated inflamm.

Question 51

immune complex glomerulonephritis pathogenesis

Answer 51

- form. of immune complexes in circulation in Ag excess - deposition in glomerular BM - complement/Neut activation - chronic: mesangial cell proliferation, collagen deposition - decreased renal fx due to increased permeability to protein and dec. perfusion of the nephron

Question 52

renal failure in chronic glomerulonephritis char. by

Answer 52

- protein losing nephropathy | - dec. renal perfusion

Question 53

mech. of Type IV hypersensitivity rxn

Answer 53

- cell mediated immunity w/lymphokine mediated indirect effects - CD8-mediated cytotoxicity antigen-sensitized cytotoxic CD8 T-cells --> Ag-altered epithelial cells --> Cell lysis/Necrosis/apoptosis