Wound healing Flashcards
used spiritual and physical
methods of wound care
2000 B.C: Sumerians
they were the ones
who first documented the process of
wound healing mostly based on spiritual
concepts
Babylonian time
– first to differentiate infected and non-infected wounds
Egyptians
1650 B.C. – Use of ______ as antibacterial, _____ as
absorbent, and _____ as barrier
honey; lint; grease
Edwin Smith Surgical Papyrus, a copy of
a much older document, describes at
least___ different types of wounds.
48
classified Acute vs Chronic wounds
Greeks
shown importance of moisture
to wound healing
200 A.D. - Galen
T or F
epithelialization rate increases by 50% in
a moist wound environment when
compared to a dry wound environment
T
Discovery of Antiseptics (Soap &
Hypochlorite)
o Ignaz Philipp Semmelweis, a Hungarian
obstetrician, noted that the incidence of
puerperal fever was much lower if
medical
1818-1865
Germs introduced
to wound cause infections
Louis Pasteur
Discovery of phenol for soaking instruments
Joseph Lister
antiseptic
dressings using gauze + iodoforms
Robert Wood Johnson
led to the development of polymeric
dressings.
1960-1970
any break in the integrity of the epithelial lining
e.g. skin or mucosal linings will start cascade of
events that will repair damage (does not occur
one after the other, they overlap)
WOUND
PHASES OF WOUND HEALING
o Hemostasis & Inflammation
o Proliferative Phase
o Maturation & Remodeling
o Epithelialization & Wound Contraction
The exposure of factors underneath the
epithelium, usually fibrin that triggers the
migration of platelets there and trigger the
coagulation cascade – and that part is the first
part of wound healing which is called
_______
“HEMOSTASIS”
first thing you can do to stop the bleeding
is to apply direct pressure because hemostasis
which is the normal function of the body would
attempt to stop the bleeding by platelet
aggregation and formation of what you called
__________
fibrin clot
the platelet secretes some co-factors
leading to the migration of the inflammatory cells
into the site of injury. And usually this are heralded
first with your neutrophils, white blood cells which
secretes further other factors that leads to the
migration of macrophages and later on
lymphocytes. This is what you call now the
________________
“INFLAMMATORY PHASE”
The macrophages that have migrated there will
secrete factors that will attract now your fibroblast
which heralds now the next part of the wound
healing: ________
PROLIFERATION
First action is to stop bleeding by formation of clot and
activation of
coagulation cascade
serves as the scaffolding of or cellular
infiltration
Fibrin Clot
In first two phases which are the hemostasis and
inflammation, this happens relatively fast, they
usually overlap with each other in first ___ hours
24 to 48
causes the migration of your white
blood cells, PMN’s
PDGF
• First infiltrating cells (24-48 hrs.)
• Phagocytes for bacteria and debris (initial
protectors)
• Major source of cytokines and collagenases
• TNF-α3 which may have a significant influence on
subsequent angiogenesis and collagen synthesis
• As the aforementioned cells appear, what they
secrete also increase.
• Collagen I ® Fibronectin ® Collagen III
Polymorphonuclear Leukocytes (PMNs )
• Second group of inflammatory cells (48-96 hrs. post
injury) infiltrating cells
• They produce most of the factors for wound
healing
• Phagocytes (more efficient) synthesize O2 (free)
radicals and nitric oxide
• Recruits and activates other cells via cytokines
and growth factors
• Regulate cell proliferation, matrix synthesis and
angiogenesis
Macrophages
• Less numerous than macrophages (1 week
post injury)
• Their presence is not fully understood because no
significant function has been identified
• Effects on modulation of wound environment
• Bridge the transition from inflammatory to
proliferative phase (modulate the wound
environment)
• They act like a marker that this wound is now going
to proliferative phase from inflammatory phase
• Role not fully defined possible effects on
modulation of wound environment.
T Lymphocytes
are the first collagen fibers
that are being deposited. They do not provide tensile
strength but they provide the lattice work or the
deposition of the mix group of collagen which is your
collagen I
Collagen III and fibronectin
It is only when the deposition of _____that the
wound starts to have the tensile strength
collagen I
leads to the migration of endothelial cell to
trigger angiogenesis which is an important phase to
herald now the start of the proliferative phase
VEGF
• Early phase of healing
• Collagen synthesis (function of fibroblasts) and
Angiogenesis (function of endothelial cells)
• From 4th to 12th day post injury (during this time,
wound tensile strength starts to occur and
increase with time).
• Fibroblast migration due to PDGF (from
macrophage)
• Endothelial cells migrate, replicate and form new
capillary tubules due to cytokines. TNF, TGF, &
VEGF
PROLIFERATIVE PHASE
•___ are the last cell
populations to infiltrate the healing wound, and
the strongest chemotactic factor for fibroblasts is
_____
Fibroblasts and endothelial cells
PDGF.
the most abundant protein in
the body, plays a critical role in the
successful completion of adult wound
healing.
Collagen
KNOWN FACTORS THAT HINDERS WOUND
HEALING
o Infection
o Foreign bodies
is the major component
of extracellular matrix in skin
Collagen type 1
which is also normally present in
skin, becomes more prominent and
important during the repair process
Collagen type 3
comprise a large portion
of the “ground substance” that makes up
granulation tissue
Glycosaminoglycan