Tissue Repair

Question 1

the two types of reactions in repair are

Answer 1

• regeneration

- scar formation

Question 2

tissue replaces damaged components and returns to a normal state is called

Answer 2

regeneration

Question 3

damaged tissues incapable of complete restitution and/or supporting structures of tissue are severely damaged is called

Answer 3

scar formation

Question 4

what is fibrosis

Answer 4

the extensive deposition of collagen in lungs, liver, kidney, and other organs due to chronic inflammation

Question 5

cell types that repair injured tissue

Answer 5

• remnants of injured tissue
• vascular endothelial cells
• fibroblasts

Question 6

function of remnants of injured tissues

Answer 6

attempt to restore normal structure

Question 7

function of vascular endothelial cells

Answer 7

create new vessels that provide nutrients for the repair process

Question 8

function of fibroblasts

Answer 8

source of fibrous tissue forming the scar to fill in defects that cannot be corrected by regeneration

Question 9

key processes of cell proliferation

Answer 9

DNA replication and mitosis

Question 10

G1 phase=

Answer 10

pre synthetic growth phase

Question 11

S phase=

Answer 11

DNA synthesis phase

Question 12

G2 phase=

Answer 12

premitotic growth phase 2

Question 13

M phase=

Answer 13

mitotic phase

Question 14

non dividing cells are either in:

Answer 14

• cell cycle arrest (G1) or

- they exit the cycle to enter a phase (G0)

Question 15

physiologic cell proliferation is caused by:

Answer 15

repair

Question 16

pathologic proliferation is caused by:

Answer 16

cancer

Question 17

ability of tissue to repair themselves is influenced by their:

Answer 17

intrinsic proliferative capacity

Question 18

3 types of tissues involved in proliferation capacity

Answer 18

1. labile (continuously dividing) tissues
2. stable tissues
3. permanent tissues

Question 19

examples of labile (continuously diving) cells that have a short life span

Answer 19

-bone marrow, skin, oral mucosa, GI tract, ducts draining exocrine glands

Question 20

stable tissue quiescent cells (in G0 stage) have what kind of proliferation capacity?

Answer 20

have minimal replicative activity (can proliferate in response to injury and loss of tissue mass)

Question 21

stable cells constitute what aspect of most solid tissues?

Answer 21

the parenchyma of most solid tissues (kidney, liver, pancreas, endothelial cells, fibroblasts, smooth muscle cells)

Question 22

what is unique about permanent tissues?

Answer 22

terminally differentiated and non proliferative in postnatal life

Question 23

examples of permanent tissues with long life spans

Answer 23

neurons, cardiac, and skeletal muscle

Question 24

2 characteristic properties of stem cells

Answer 24

1. self renewal capacity

2. asymmetric replication

Question 25

what is asymmetric replication of stem cells mean?

Answer 25

- some differentiate to a specific cell type | - some remain undifferentiated (these maintain their self-renewal capacity

Question 26

embryonic stem cell characteristics

Answer 26

most undifferentiated stem cells | -capacity to generate multiple cell lineages (neurons, cardiac muscle, liver cells)

Question 27

adult stem cells (tissue stem cells) are:

Answer 27

less undifferentiated than embryonic stem cells and found among differentiated cells with an organ or tissue

Question 28

what are growth factors?

Answer 28

proteins that stimulate the survival and proliferation of particular cells that can promote migration, differentiation, and other cellular responses

Question 29

what are growth factors produced by?

Answer 29

by macrophages and lymphocytes, parenchymal cells or stream cells (connective tissue)

Question 30

growth factors can affect cell proliferation by promoting:

Answer 30

- cell entry into cell cycle - replication (mitosis) - prevention of apoptotic death (survival) - function of growth control genes

Question 31

other things that growth factor can stimulate are:

Answer 31

angiogenesis, contractility, and fibrogenesis

Question 32

3 types of signaling mechanisms of growth factor

Answer 32

- autocrine - paracrine - endocrine

Question 33

type of signaling mechanism where a substance acts on cell that secretes it (ex: lymphocyte proliferation, liver regeneration)

Answer 33

autocrine

Question 34

type of signaling mechanisms that affects cell in the vicinity and recruits inflammatory cells in wound healing

Answer 34

paracrine

Question 35

type of signaling mechanisms that acts on target cells at a distance (ex: hormones)

Answer 35

endocrine

Question 36

examples of lipid based signaling mechanisms that can affect receptors inside the cell

Answer 36

vitamin D, steroid, thyroid hormones

Question 37

how does tissue repair depend on interactions between cells and ECM

Answer 37

regulates proliferation, movement, and differentiation of cells within it

Question 38

what are the 2 forms of the ECM

Answer 38

- interstitial matrix | - basement membrane

Question 39

part of ECM that is located in spaces between cells in connective tissue, and between epithelium and vascular/ smooth muscle structures

Answer 39

interstitial matrix

Question 40

part of ECM that is a matrix of connective tissues that is highly organized around epithelial, endothelial, and smooth muscle cells (found between epithelium and mesenchymal cells)

Answer 40

basement membrane

Question 41

components of ECM can include

Answer 41

- collagens and elastin - proteoglycans and hyaluronan - adhesive glycoproteins

Question 42

collagens and elastin contribute to

Answer 42

tensile strength and recoil of ECM

Question 43

proteoglycans and hyaluronan contribute to

Answer 43

water-hydrated gels for resilience and lubrication of ECM

Question 44

how can ECM help control cell proliferation

Answer 44

signals through cellular receptors of the intern family

Question 45

what is needed for renewal of structure (stroma of the parenchymal cells)

Answer 45

basement membrane

Question 46

what cells depend on ECM to reestablish normal structure

Answer 46

labile and stable cells

Question 47

regeneration cannot be accomplished if there is severe or chronic damage to:

Answer 47

parenchymal cells, stroma, or non-dividing cells

Question 48

in scar formation, what begins within 24 hours of injury

Answer 48

fibroblasts and endothelial cells proliferate

Question 49

in scar formation, what occurs in 3-5 days

Answer 49

granulation tissue (seen beneath a scab) with delicate capillaries

Question 50

process of new blood vessel development from existing cells is called

Answer 50

angiogenesis

Question 51

angiogenesis is primarily in

Answer 51

venules

Question 52

3 main phases of wound healing

Answer 52

- inflammation - formation of granulation tissue - ECM deposition and remodeling

Question 53

what can occur in wound healing for larger wounds

Answer 53

contraction (wound dimples in a little)

Question 54

primary example of healing by first intention

Answer 54

surgical scar

Question 55

in first intention healing, what regeneration predominates

Answer 55

epithelial regeneration predominates over fibrosis

Question 56

most important cause of delayed healing

Answer 56

infection