Lecture 12 2/22/24

Question 1

What are the options for healing responses in the tissues?

Answer 1

-return to normal structure/function
-healing by replacement fibrosis
-healing by sequestration (abscess/granuloma)

Question 2

What are the characteristics of healing by regeneration?

Answer 2

-supporting connective tissue/basement membrane is intact
-tissue has capacity to regenerate

Question 3

How long does healing by regeneration take?

Answer 3

3-5 days, then tissue returns to “normal”

Question 4

What are the characteristics of healing by repair?

Answer 4

-supporting connective tissue/basement membrane is lost OR
-tissue not capable of proliferating
-triggers more complicated wound healing involving granulation tissue and scarring

Question 5

What are the steps in wound healing?

Answer 5

-hemostasis
-acute inflammation
-proliferation
-remodeling

Question 6

What are the general steps of hemostasis?

Answer 6

-vasospasm
-platelet aggregation
-platelet plug formation
-blood vessel healing

Question 7

What happens during the acute inflammation stage of wound healing?

Answer 7

-phagocytosis of dead cells and bacteria
-breakdown of extracellular matrix due to sloppy phagocytosis

Question 8

Which two components are replaced during the proliferation stage of wound healing?

Answer 8

-epithelial component
-stromal component

Question 9

What are the characteristics of epithelial proliferation?

Answer 9

-similar to healing by regeneration
-must re-establish basement membrane

Question 10

What is granulation tissue?

Answer 10

connective tissue + blood vessels

Question 11

Which growth factor triggers connective tissue/fibrosis development during stromal proliferation?

Answer 11

TGF-B

Question 12

Which growth factor triggers angiogenesis during stromal proliferation?

Answer 12

VEGF

Question 13

What are the characteristics of granulation tissue?

Answer 13

-no overlying epithelium
-often has surface neutrophils
-neovascularization and fibroblasts

Question 14

How does granulomatous inflammation differ from granulation tissue?

Answer 14

granulomatous inflammation: form of chronic inflammation w/ epithelioid macrophages/multi-nucleated giant cells
granulation tissue: form of tissue repair involving capillaries and fibroblasts

Question 15

What causes wound contraction?

Answer 15

myofibroblasts

Question 16

What happens when granulation tissue is replaced with mature fibrous connective tissue?

Answer 16

-decrease in:
–inflammation
–fibroblasts
–blood vessels
-collagen stays but loses cellular component

Question 17

What are the characteristics of mature fibrous connective tissue/scars?

Answer 17

-well-organized
-avascular
-depressed
-pale

Question 18

How does primary vs secondary intention wound healing differ?

Answer 18

-primary intention is very quick healing and less severe
-secondary intention is more severe, with more granulomatous healing

Question 19

How does fibrin/fibrinous inflammation differ from fibrosis/fibrous tissue?

Answer 19

-fibrin/fibrinous inflammation: formed from fibrinogen, forms soft adhesions, component of acute inflammation
-fibrosis/fibrous tissue: collagen produced by fibroblasts, forms tough adhesions, common end stage of chronic inflammation

Question 20

Why does fibrosis appear indented or pitted?

Answer 20

-loss of tissue
-contraction