Unit 3 - Lecture 1 Flashcards
A couple of days after being wounded, what does the body do in response?
inflammation, clot formation, and chemotaxis occurs
Six to twelve days after wounding, how does the body respond?
proliferation, re-epithelialization, angiogenesis and granulation tissue, and provisional matrix
Twelve days after wounding, how does the body respond?
maturation, collagen deposition, and wound contraction
What are the goals of repair?
reconstiture injured tissue to optimal morphology and if that is not achievable replace injured tissue with viable tissue
If injured tissue needs to be replaced, what type of tissue will replace it?
granulation tissue and then fibrous tissue
What does parenchymal repair depend on?
capacity of residual cells to proliferate and stromal preservation
What two things must be intact for stromal preservation?
the basement membrane and blood supply
What are liable cells?
cells that renew
What are examples of liable cells?
epithelium (especially in the skin and gut) and bone marrow
What are stable cells?
cells that replace themselves as needed
What are the categories for stable cells?
connective tissue cells and epithelial cells
What type of connective tissue cells are stable cells?
fibroblasts, endothelial cells, bone, and cartilage
What type of epithelial cells are stable cells?
liver, kdiney, and exocrine pancreatic acini cells
What are permanent cells?
cells that are not replaced
What are some examples of permanent cells?
myocardiocytes and neurons
What is the most common type of repair?
repair by fibrous connective tissue
What is fibrous connective tissue also known as?
scar tissue
In granulation tissue, what direction do fibroblasts grow?
perpendicular to new blood vessels
What forms the scab in granulation tissue?
neutrophils
What are the two types of wound healing?
primary intention and secondary intention
Characterize healing by first intention.
clean, incised, minimal infection, minimal foreign material
When does second intention healing occur?
when the cut edges of the skin are not brought into appropriate aposition for healing
What is delayed healing in second intention healing caused by?
increased necrotic debris, foreign material, infection, and presence of exuberant granulation tissue
A.
activation of macrophages and lymphocytes
B.
Growth factors - PDGF, FGF, TGF-beta
C.
Cytokines - TNF, IL-1, IL-4, IL-13
D.
decreased metalloproteinase activity
E.
proliferation of fibroblasts, endothelial cells, and specialized fibrogenic cells
F.
increased collagen synthesis
G.
decreased collagen degradation
H.
fibrosis
A.
defect caused by loss or breakdown of epithelium and underlying tissue +/- infection
B.
blood clot
C.
necrotic slough
D.
acute inflammation
A.
slough and scab
B.
epithelial proliferation
C.
vascular granulation tissue
D.
zone of hyperemia
A.
epithelial proliferation across granulation tissue surface before gradually shedding scan
B.
fibrous granulation tissue beginning to contract, pulling wound edges closer together
C.
hyperemia
A.
pale depressed scar with surrounding puckering caused by wound contraction
B.
epidermis thin
C.
dermal fibrous scar devoid of skin appendages
1
injury/agent
2
vascular response and cellular exudation
3
acute exudation
4
agent destroyed
5
little or no necrosis
6
exudate resolved ex. Friction blister
7
resolution of normal
8
exudate organized ex. Surgical incision
9
scarring
10
agent not quickly destroyed
11
necrosis
12
liable or stable cells
13
framework intact ex. Toxic tubular nephrosis
14
regeneration and resolution of normal
15
framework destroyed ex. Gastric ulcer
16
scarring
17
permanent cells ex. Myocardial infarct
18
scarring
A.
epidermis
B.
blood clot
C.
dermis
A.
redness and swelling
B.
zone of acute inflammation, formation of granulation tissue
A.
epithelial proliferation and repair (pinkish-red scar)
B.
maturation fibrous granulation tissue
A.
white scar
