Week 4: Tissue Repair

Question 1

two ways tissues can be repaired

Answer 1

regeneration, scar formation

Question 2

repair in which tissue is returned to its normal state

Answer 2

regeneration

Question 3

repair in which connective tissue fills in gaps and mends the tissue

Answer 3

scar formation (“fibrosis”)

Question 4

tissues are divided into three groups

Answer 4

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

Question 5

examples of continuously dividing tissues

Answer 5

bone marrow, skin, GI epithelium

Question 6

continuously dividing tissue:
cells continuously ______
can easily _____ after ____
contain pool of _______

Answer 6

• proliferating
• regenerate, injury
• stem cells

Question 7

stable tissues:

• cells have ____ to _____
• can _____, though, if injured

Answer 7

• limited ability, proliferate

- regenerate

Question 8

examples of stable tissues

Answer 8

liver, kidney

Question 9

permanent tissues:

• cells ____ ______
• can’t ______ (so injury always leads to ___)

Answer 9

• can’t proliferate

- can’t regenerate, scar

Question 10

examples of permanent tissue

Answer 10

neurons, cardiac muscle

Question 11

network that surrounds cells

Answer 11

extracellular matrix (ECM)

Question 12

two forms of ECM

Answer 12

interstitial matrix, basement membrane

Question 13

ECM functions

Answer 13

sequesters water/minerals, gives cells scaffold to adhere to, stores growth factor

Question 14

what cells make collagen?

Answer 14

fibroblasts

Question 15

____ regulates proliferation, movement, and differentiation of the cells living in it

Answer 15

ECM

Question 16

if you screw up the ECM, you (can/can not) regenerate

Answer 16

can not

Question 17

regeneration occurs ____ in labile tissues and occurs _____ in stable tissues

Answer 17

all the time, in limited form

Question 18

what happens when you remove one kidney?

Answer 18

the other undergoes hypertrophy and hyperplasia

Question 19

what happens when you remove half of a liver?

Answer 19

it will grow back

Question 20

in labile tissues, if demand increases, supply ____ _____

Answer 20

increases easily

Question 21

4 components to scarring procces

Answer 21

• new vessel formation
• fibroblast proliferation
• formation of a collagen scar
• remodeling of scar

Question 22

term for new vessel formation

Answer 22

angiogenesis

Question 23

scarring within the first 24 hours

Answer 23

• endothelial cells start proliferating

- fibroblasts arrive

Question 24

scarring process: 24 hours to few days

Answer 24

granulation tissue is formed

Question 25

scarring process: weeks later

Answer 25

- dense fibrosis (scar) | - scar is remodeled over time

Question 26

overview process of scarring (simplified version)

Answer 26

- make granulation tissue | - turn it into a chunk of collagen

Question 27

granulation tissues is made up of 3 things. what are they?

Answer 27

- new blood vessels - fibroblasts - loose connective tissue

Question 28

true/false, granulation tissue is the same thing as a granuloma

Answer 28

false, it is NOT

Question 29

type of healing in which wounds closes easily

Answer 29

first intention healing

Question 30

first intention healing - ___ wounds - ____ _____ predominates over _____ - healing is ____

Answer 30

- small - epithelial regeneration, fibrosis - fast

Question 31

examples of first intention healing

Answer 31

paper cuts, well-approximated surgical incisions, replaced periodontal flaps

Question 32

did you study the "healing by first intention " timeline slide?

Answer 32

I hope you did! It's probably going to be exam material!

Question 33

healing that occurs in larger wounds that have gaps between margins

Answer 33

second intention healing

Question 34

second intention healing - ___ predominates over _______ - healing is ____

Answer 34

- fibrosis over epithelial regeneration | - slower

Question 35

examples of second intention healing

Answer 35

infarction, large burns/ulcers, extraction sockets, gingivectomies

Question 36

second intention healing has...

Answer 36

- more inflammation - more granulation tissue - wound contraction

Question 37

did you study the "healing by second intention " timeline slide?

Answer 37

I hope you did!!

Question 38

wound strength 3 months after suture removal; does it get back to normal?

Answer 38

70-80%, NO

Question 39

there is a ____ ___ in wound strength in the ___ ___ after suture removal

Answer 39

rapid increase, four weeks

Question 40

extrinsic factors that lead to bad wound healing?

Answer 40

infection, diabetes, steroids; aberrant cell growth

Question 41

aberrant cell growth leads to...

Answer 41

keloid scars, proud flesh