Healing And Repair: Inflammation Flashcards
Injury to cells and tissues sets in motion a series of events that contain the damage and initiate the healing process.
This process can be separated broadly into _______ and ______
regeneration and repair .
Regeneration results in the ___________ of lost or damaged tissue
complete restitution
Repair may ___________ but can cause ________
restore some original structures
structural derangements.
Regeneration refers to the ______ of cells and tissues to _______. e.g liver growth after partial resection or necrosis
proliferation
replace lost structures
Repair most often consists of a combination of ________ and _________ by the deposition of ______.
regeneration and scar formation
collagen
The relative contribution of regeneration and scarring in tissue repair depends on the _____________ and __________
ability of the tissue to regenerate and the extent of the injury.
For instance, a superficial skin wound heals through the ________ of the surface epithelium.
regeneration
Scar formation is the predominant healing process that occurs when the —————— is damaged by severe injury .
extracellular matrix (ECM) framework
____________ (ECM)
extracellular matrix
Control of normal cell proliferation and tissue growth
In adult tissues, the size of cell populations is determined by the _____ of cell proliferation, ________ , and ______
rates; differentiation
death by apoptosis.
Cell proliferation can be stimulated by only physiologic conditions.
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can be stimulated by both physiologic and pathologic conditions.
The tissues of the body are divided into three groups on the basis of the proliferative activity of their cells:
___________ (labile tissues),
_______ (stable tissues), and
___________ (permanent tissues).
continuously dividing
quiescent
nondividing
Continuously dividing tissues proliferate throughout life.
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Labile cells
These tissues include :
surface _____, such as ___________________, oral cavity, vagina, and cervix;
the lining ____ of all the ______ of the body; the columnar epithelium of the ______________; the transitional epithelium of the ———-, and cells of the ________ and hematopoietic tissues.
In most of these tissues mature cells are derived from ______ cells.
epithelia; stratified squamous epithelia of the skin
mucosa; excretory ducts of the glands
GI tract and uterus
urinary tract; bone marrow
adult stem
Quiescent tissues normally have a (low or high?) level of replication
The cells can undergo ______ in response to stimuli and are thus capable of reconstituting the tissue of origin. The examples include
Parenchymal cells of _____,_____, and ______;
Mesenchymal cells such as ______ and ______; vascular _______ cells; and ___- and other _________.
Low
rapid division
liver, kidneys, and pancreas
fibroblasts and smooth muscle
endothelial; lymphocytes; leukocytes
Nondividing tissues contain cells that have ______ and cannot undergo _______ in ______ life.
The examples include
______,______, and ________ cells.
left the cell cycle
mitotic division ; postnatal
Neurons, skeletal and cardiac muscle
Wound healing is a (simple or complex?) and (static or dynamic?) process of replacing _____- and ______ cellular structures and tissue layers.
Complex ; dynamic
devitalized
missing
The human adult wound healing process can be divided into 3 or 4 distinct phases. Earlier authors referred to 3 phases denoted as ________,_______ and _______
In the 4-phases concept, there are the _____,______,_______,_______phase.
In the 3-phases approach, the ______ phase is contained within the ______ phase.
inflammatory, proliferative, and remodeling .
hemostasis phase, the inflammatory phase, the proliferative phase, and the remodeling
hemostasis; inflammatory
Types of wound healing
_______ wound healing or healing by first intention.
___________ wound healing
_________ healing or healing by secondary intention
Primary
Delayed primary
secondary
Category 1
Primary wound healing or healing by first intention occurs within ____ of repairing a full-thickness surgical incision.
This surgical insult results in the death of a (minimal or maximal?) number of cellular constituents.
__________ to close the wound occurs with formation of a relatively (thin or thick?) scar.
hours
Minimal
Re-epithelialization
Thin
Category 2
If ________________________________, delayed primary wound healing transpires.
This type of healing is seen in cases of _______
the wound edges are not reapproximated immediately
Category 2
By the ____ day, phagocytosis of contaminated tissues is well underway
There is ongoing ______, _____ deposition, and maturation.
Foreign materials are walled off by _______ that may metamorphose into ______ cells, which are encircled by _________, forming ______.
Usually the wound is closed ______ at this juncture.
If the “cleansing” of the wound is incomplete, _______ can ensue, resulting in ________
fourth; epithelization; collagen
macrophages; epithelioid; mononuclear leukocytes; granulomas
surgically; chronic inflammation ; prominent scarring.
Category 3
Secondary healing or healing by secondary intention.
Secondary healing results in _________ that is more intense than with primary wound healing.
In addition, a larger quantity of ________ is formed.
Secondary healing results in pronounced _______ of wounds.
Fibroblastic differentiation into _____ contribute to wound contraction.
an inflammatory response
granulomatous tissue
contraction
myofibroblasts
Formation of Blood Clot.
Wounding causes the rapid activation of coagulation pathways, with formation of a blood clot on the wound surface .
The clot contains ___ cells, ____,_______,_ and ______ components.
The clot serves to stop bleeding and also as a scaffold for migrating cells, which are attracted by growth factors, cytokines and chemokines released into the area.
In large wounds , the fibrin clot is larger, and there is more exudate and necrotic debris in the wounded area.
Within _______, ______ appear at the _____ of the incision. They release proteolytic enzymes that clean out debris and invading bacteria.
red; fibrin, fibronectin, and complement
24 hours; neutrophils; margins
Inflammatory phase commences during the hemostasis phase, the early component of the inflammatory phase is predominated by the influx of the _________
The later component predominated by __________
Within the first 6-8 hours, the next phase of the healing process is underway, __________
.
polymorphonuclear leukocytes (PMNs)
monocytes/macrophages.
PMNs engorging the wound.
TGF-β facilitates _______ from surrounding blood vessels.
PMN migration
The PMNs attain their maximal numbers in _______ hours.
24-48
Monocytes are termed macrophages once they ________
leave the vessel.
Macrophages clear extracellular debris, fibrin, and other foreign material at the site of repair, and promoting _______ and _________ deposition.
angiogenesis and ECM
Formation of Granulation Tissue/Proliferation.
Fibroblasts and vascular endothelial cells proliferate in the first _______ of the repair process to form _____ tissue, which is a hallmark of tissue repair.
It is ____ color and ______ with ______ appearance on the surface of wounds.
It is characterised by the presence of ________ and the proliferation of _______.
24 to 72 hours
granulation
pink and soft with granular
new small blood vessels (angiogenesis)
fibroblasts
Granulation tissue progressively invades the incision space; The amount of granulation tissue that is formed depends on the _______ created by the wound and the ________
Hence, it is much more prominent in healing by _______
By __________, granulation tissue fills the wound area and neovascularization is maximal.
size of the tissue deficit
intensity of inflammation.
secondary intention.
5 to 7 days
Scar formation/ wound contraction
The leukocytic infiltrate, edema, and increased vascularity largely disappear during the _________
There is increased accumulation of _____ within the wound area and regression of _____
The granulation tissue scaffolding is converted into a _____,______ scar, composed of spindle- shaped _____, dense _____, fragments of elastic tissue, and other ECM components.
The dermal appendages that have been destroyed in the _____________ are permanently lost
second week.
collagen; vascular channels.
pale, avascular
fibroblasts; collagen
line of the incision
Scar formation/wound contraction
By the end of the first month, the scar is made up of ______ connective tissue devoid of __________, covered by intact ______
Wound contraction generally occurs in (small or large?) surface wounds.
The contraction helps to close the wound by ____________ and by reducing the wound surface area.
acellular; inflammatory infiltrate
epidermis; large
decreasing the gap between its dermal edges
The initial steps of wound contraction is the formation, of a network of _______ that express smooth muscle ______ and ______
These cells produce (small or large?) amounts of ECM components.
myofibroblasts
α-actin and vimentin
Large
Myofibroblasts are formed from tissue _____ , bone marrow ______, or from _____ cells, through the process of ________ transition.
fibroblasts
fibrocytes
epithelial
epithelial-to-mesenchymal
Connective Tissue Remodeling.
The replacement of granulation tissue with a scar involves changes in the composition of the _______.
The balance between _______ and ___________ results in remodeling of the connective tissue framework .
ECM
ECM synthesis and degradation
Degradation of collagen and other ECM proteins is achieved by _____________
matrix metalloproteinases (MMPs).
______ collagens (mostly _____ collagen) form a major portion of the connective tissue in repair sites and are essential for the development of _____ in healing wounds.
Fibrillar
type I
strength
By the end of the first week, wound strength is approximately ____% that of unwounded skin.
Wound strength increases rapidly over the next ________, slows down at approximately the ______ after the original incision, and reaches a plateau at about ___% to __% of the tensile strength of unwounded skin.
10
4 weeks
third month
70; 80
Lower tensile strength in the healed wound area may persist for life.
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Systemic factors that influence wound healing
Nutrition deficiency inhibit ______ synthesis and retard healing. ______ and ________ deficiency are common examples.
Metabolic status -________ for example, is associated with delayed healing.
Circulatory status - Inadequate blood supply impairs wound healing. E.g ________ or venous abnormalities (e.g., ________)
Hormones such as ______ have anti- inflammatory effects that influence various components of inflammation. They also inhibit collagen synthesis.
collagen; Protein and vitamin C
Diabetes mellitus
arteriosclerosis; varicose veins
glucocorticoids
Local factors that influence wound healing
Local factors include :
______ - is the single most important cause of delay in healing, because it results in persistent tissue injury and inflammation.
Mechanical factors, such as ___________ delay healing, by compressing ______ and separating the ______ of the wound.
Foreign bodies, such as unnecessary sutures or fragments of steel, glass, or even bone, constitute impediments to healing.
Size, location, and type of wound.
Infection
early motion of wounds; blood vessels; edges
Wounds in richly vascularized areas, such as the ____, heal (slower or faster?) than those in poorly vascularized ones, such as the _____.
face
Faster
foot
small incisional injuries heal (slower or faster?) and with (more or less?) scar formation than large excisional wounds or wounds caused by blunt trauma.
Faster
Less
Complications of wound healing
Inadequate formation of granulation tissue or scar :
wound ______ and _______
Excessive formation of the components of the repair process:
______ scars
______.
exuberant _______.
exuberant proliferation of _____ and other connective tissue elements called _____, or aggressive _____.
dehiscence; ulceration
hypertrophic; keloids; granulation
fibroblasts; desmoids; fibromatoses
Exaggerated contraction :
Contracture - Contractures are commonly seen after ______ and can compromise the __________
serious burns
movement of joints
Future and controversies
_____ techniques, _____ techniques, and other modalities are being explored to enhance the proliferation of cells, the migration of cells, and the acceleration of the healing of wounds.
Human ___________ developed in ________-like conditions has been shown to improve healing times in _____ facial skin.
Laser; nonlaser
cell–conditioned media
embryologic; postlaser
Fetal tissue can heal _____ due to the unique characteristics of ________ and _________ cells and the functioning of the _________ system.
scarless
fetal epithelial and mesenchymal
fetal immune
The inclusion of transforming growth factor (TGF)–β3 during the healing of wounds in adults can be beneficial.
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___________________ (TGF)
transforming growth factor
________ oxygen has also been used to promote healing.
Hyperbaric
Agents such as _____________ (PRP) and _______ (EPO) are modulators that have a positive effect on tissue regeneration and have been used successfully to enhance the healing of wounds.
platelet-rich plasma
erythropoietin
Nutritional aspects are also critical for proper wound healing.
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Improvement in the nutritional status of adults correlates with enhanced wound healing.
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Honey was been shown to be (more or less?) beneficial,
Less
In a rat model, _____ from the ____ pine (Pinus _____) increased the rate of wound healing.
pine bark; Turkish
brutia
Aloe ______ has enhanced healing properties when compared to Aloe _____.
arborescens
vera
Appropriate neurological stimulation is also important in the healing of wounds.
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Reparative strategies involving engineered tissue matrices, either exogenous or endogenous, have also been used in healing
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______ cells continue to be a new frontier of research in the armamentarium of wound healing strategies.
Stem
