SlideShare a Scribd company logo
1 of 48
Download to read offline
WOUNDHEALINGWOUNDHEALING
PRESENTEDBY
DRNOBODY
MS RESIDENT
GYNAE & OBS, UNIT 2
XMEDICAL
DEFINITION
 Wound healing refers to the body’s
replacement of destroyed tissue by living
tissue.
 Can be achieved by 2 processes: tissue
regeneration &scar formation.
 Dynamic balance between these 2 is different
in different tissues.
Introduction
 During healing, a complex cascade of cellular
events occur to achieve resurfacing,
reconstitution and restoration of tensile strength
of injured tissue.
 Wound healing occurs in 3 phases
1. Inflammatory phase
2. Proliferative phase
3. Remodeling phase
Stages of wound healing
I. Inflammatory phase
A. Immediate to 2-5 days
B. Hemostasis
1. Vasoconstriction – damaged blood vessels
constrict
2. Hemostasis is achieved by formation of platelet
plug & activation of extrinsic & intrinsic clotting
pathways.
3. Formation of a provisional fibrin matrix
C. Recruitment of inflammatory cells into the
wound by potent chemoattractants
Early Events in Inflammation
 Fibrin and fibronectin form a lattice that
provides scaffold for migration of
inflammatory, endothelial, and mesenchymal
cells.
 Neutrophilic infiltrate appears: removes dead
tissue & prevent infection.
 Monocytes/macrophages follow neutrophils:
orchestrated production of growth factors &
phagocytosis.
Late Events in Inflammation
 Entry of lymphocytes.
 Appearance of mast cell
II. Proliferative phase
A. 2 days to 3 weeks
B. Granulation tissue formation (composed of
fibroblasts,macrophages and endothelial cell)
C. Angiogenesis
D. Contraction
I. Wound edges pull together to reduce the
defect
E. Epithelialization
I. Epithelial cells migrate across the new tissue to
form a barrier between the wound and the
environment
Mesenchymal cell proliferation
 Fibroblasts are the major mesenchymal cells
involved in wound healing, although smooth
muscle cells are also involved.
 Macrophage products are chemotactic for
fibroblasts. PDGF, EGF, TGF, IL-1,
lymphocytes are as well.
 Replacement of provisional fibrin matrix with
type III collagen.
Angiogenesis
 Angiogenesis reconstructs vasculature in
areas damaged by wounding, stimulated by
high lactate levels, acidic pH, decreased O2
tension in tissues.
 Recruitment & assembly of bone marrow
derived progenitor cells by cytokines is the
central theme.
 EGF-1 is most potent angiogenic stimulant
identified. Heparin is also an important as
cofactor, TGF- alpha, beta, prostaglandins
also stimulate.
Wound healing
Epithelialization
 Basal cell layer thickening, elongation,
detachment & migration via interaction with
ECM proteins via integrin mediators.
 Generation of a provisional BM which includes
fibronectin, collagens type 1 and 3
 Epithelial cells proliferation contributes new
cells to the monolayer. Contact inhibition when
edges come together.
III. Remodeling phase
A. 3 weeks to 2 years
B. New collagen forms which increases the
tensile strength of the wound
C. 19 types identified. Type 1(80-90%) most
common, found in all tissue. The primary
collagen in a healed wound.
D. Type 3(10-20%) seen in early phases of
wound healing. Type V smooth muscle,
Types 2,11 cartilage, Type 4 in BM.
Remodelling
 The number of intra and intermolecular cross-
links between collagen fibers increases
dramatically.
 A major contributor to the increase in wound
breaking strength
 Quantity of Type 3 collagen decreases
replaced by Type 1 collagen
 Remodeling continues for 12 months, so scar
revision should not be done prematurely.
Wound Contraction
 Begins approximately 4-5 days after wounding
by action of myofibroblasts.
 Generally occurs in large surface wounds.
 Represents centripetal movement of the
wound edge towards the centre of the wound.
 Maximal contraction occurs for 12-15 days,
although it will continue longer if wound
remains open.
Wound contraction
 The wound edges move toward each other at
an average rate of 0.6 to .75 mm/day.
 Wound contraction depends on laxity of
tissues, so a buttock wound will contract faster
than a wound on the scalp or pretibial area.
 Wound shape also a factor, square is faster
than circular.
Wound Strength
 Skin wounds
 At the end of first week,wound strength is
approximately 10% of unwounded skin
 Wound strength increases rapidly over next 4
weeks and then slows down at approximately
at third month,reaches a plataue at about 70-
80% of the tensile strength of unwounded skin
 Scar tissue is ne ve r as stro ng as the o rig inal
tissue !!
Important Growth factors
responsible for wound healing
 Platelet derived growth factor:
 Promotes migration and proliferation of fibroblasts
 Is chemotactic for monocytes
 Epidermal growth factor
 Promotes growth of endothelial, epithelial cells
and fibroblasts
Growth factors in wound
healing
 Fibroblast growth factor:
 Promotes synthesis of ECM proteins including
fibronectin.
 Chemotactic for fibroblasts and endothelial cells
 Promotes angiogenesis
 Vascular Endothelial Growth Factor (VEGF)
 Angiogenesis
 Macrophage derived growth factors
 IL-1 and TNF
 Promote proliferation of fibroblasts and endothelial cells.
Wound healing
 Wound healing is accomplished in one of the
following two ways:
1. Healing by first intention (primary union)
2. Healing by second intention (secondary
union)
Healing by first intention (primary
union)
 Occurs in clean, incised wounds with good
apposition of the edges – particularly planned
surgical incisions
 (clean wounds – no infections or foreign bodies)
 The incision causes only focal disruption of
epithelial basement membrane continuity and
death of a relatively few epithelial and
connective tissue cells.
 As a result, epithelial regeneration
predominates over fibrosis
Healing by first
intention:
Sequence of events
Immediate
 The narrow
incisional space
rapidly fills with
fibrin clotted blood
 Dehydration at the
surface produces a
scab to cover and
protect the healing
repair site
Within 24 hrs
 Movement and
proliferation of
epithelial cells across
the wound resulting
in a thin, but
continuous epithelial
layer
 Early inflammation
close to the edges
(neutrophils)
2-3 days
 Neutrophils
replaced by
macrophages
 Macrophages
remove the blood
clot
 Proliferation of
epithelial cells
 Fibroblastic activity
10-14 days
 Scab loose (aka dry
clot)
 Epithelial covering
complete
 Fibrous union of
edges
 Wound still weak
 vascularization
By the end of the first month
 Scar comprises of a
cellular connective
tissue devoid of
inflammatory infiltrate,
covered by intact
epidermis
 Dermal appendages
destroyed in the line of
incision are
permanently lost
 Tensile strength of the
wound increases and
Healing by second intention
(secondary union)
 This occurs in open wounds, particularly when
there has been significant loss of tissue,
necrosis or large wounds with irregular margins
 Regeneration of parenchymal cells cannot
completely reconstitute the original architecture
 Abundant granulation tissue grows in from the
margin to complete the repair
 Granulation tissues consists of:
 ECM fibroblasts
 Macrophages, neutrophils
 New blood vessels
Healing by second
intention
(secondary union)
sequence of events
Early
A few days
1 week
Epithelial
proliferation
Capillary loops
(granulations)
Scab shed
Loose connective
Tissue formed by
fibroblasts
2 weeks onwards
Months
Full thickness of
Epithelium restored
Varying depth of
Surface depression
Thick collagenous
Scar tissue becoming
Less vascular
Wound healing
Secondary union differs from
primary union in several
respects
1. inflammatory reaction is
more intense
2. larger amounts of
granulation tissue formation
3. larger scar
4. ***wound contraction
 Myofibroblasts: modified
fibroblasts with feature of
SMC
 defect significantly
decreases in size as wound
heals.
Factors that influence healing
 Classified as
A. Systemic
and
B. Local
Systemic Factors that Delay/Retard
Wound Healing
 Nutrition
 Protein deficiency, Vitamin C deficiency
 inhibit collagen synthesis
 Zn deficiency (cofactor in type III collagenase)
 Metabolic status
 diabetes mellitus:
 Susceptibility to infection caused by impaired
circulation and increased glucose.
 Circulatory status
 inadequate blood supply
 atherosclerosis, vascular defects
 Hormones
 glucocorticoids inhibit collagen synthesis, decrease
inflammation
Local Factors that Delay/Retard
Wound Healing
 Infection
 most important cause of delayed wound healing
 Persistent injury and inflammation
 Mechanical factors
 motion early in healing
 Foreign material - like suture material and foreign bodies
 Size, location & type of wound
 wounds in ↑vascularized areas (face) heal faster than
in poorly vasc areas (tendon, feet)
 small wounds heal faster than larger
 incisions faster than blunt trauma (contusions)
Complications of wound healing
1. Deficient scar formation
2. Excessive formation of repair
components
3. Exaggerated contraction
Deficient scar formation
Can lead to two types of complications:
A. Wound Dehiscence (rupture of wound)
 most common after abdominal surgery
coughing, vomiting,
B. Ulceration - defect in the continuity
Wound Dehiscence
Excessive formation of repair
components
1. Keloid / hypertrophic scar (excess collagen)
2. Exuberant granulation or proud flesh
(excessive granulation tissue that protrudes
above the level of the surrounding skin and
impairs the growth of epithelium)
Keloid / hypertrophic scar
 Raised scars due to accumulation of excess
amounts of collagen ( type III – type I)
 Hypertrophic scars do not grow beyond the
boundaries of the original wound
 Keloids grow beyond the boundaries of the
original wound (more serious)
Keloid
Exuberant granulation (proud
flesh)
 Excessive granulation
tissue
 Protrudes above
surrounding skin
 Prevents re
-epithelialization
Exaggerated contraction
 deformation of
surrounding tissue or
wound
 Can compromise the
movement of joints.
 most common on
 palms, soles, anterior
thorax following
severe burns
Wound healing

More Related Content

What's hot (20)

Inflammation
InflammationInflammation
Inflammation
 
Wounds
WoundsWounds
Wounds
 
Haemorrhage
Haemorrhage   Haemorrhage
Haemorrhage
 
Wound healing
Wound healingWound healing
Wound healing
 
Hemorrhage
HemorrhageHemorrhage
Hemorrhage
 
Wound healing
Wound healingWound healing
Wound healing
 
Fracture
FractureFracture
Fracture
 
Hernia
HerniaHernia
Hernia
 
Bone healing
Bone healingBone healing
Bone healing
 
Wound ppt
Wound pptWound ppt
Wound ppt
 
wound healing PPT
wound healing PPTwound healing PPT
wound healing PPT
 
Benign and malignant tumor comparison
Benign and malignant tumor comparisonBenign and malignant tumor comparison
Benign and malignant tumor comparison
 
Necrosis
NecrosisNecrosis
Necrosis
 
Anesthesia ppt
Anesthesia pptAnesthesia ppt
Anesthesia ppt
 
Inflammatory process
Inflammatory processInflammatory process
Inflammatory process
 
Neoplasia
NeoplasiaNeoplasia
Neoplasia
 
Atherosclerosis ppt
Atherosclerosis pptAtherosclerosis ppt
Atherosclerosis ppt
 
Wound healing dr sumer
Wound healing   dr sumerWound healing   dr sumer
Wound healing dr sumer
 
Myocardial infarction
Myocardial infarctionMyocardial infarction
Myocardial infarction
 
Gangrene
GangreneGangrene
Gangrene
 

Similar to Wound healing

Woundhealing drneerajjain
Woundhealing drneerajjainWoundhealing drneerajjain
Woundhealing drneerajjainDr. Neeraj Jain
 
Wound healing [including healing after periodontal therapy]
Wound healing [including healing after periodontal therapy]Wound healing [including healing after periodontal therapy]
Wound healing [including healing after periodontal therapy]Jignesh Patel
 
Inflammatory Principles & Athletic Rehab
Inflammatory Principles & Athletic RehabInflammatory Principles & Athletic Rehab
Inflammatory Principles & Athletic RehabJLS10
 
Wound healing
Wound healingWound healing
Wound healingUCMS
 
wound healing [Autosaved].pptx
wound healing [Autosaved].pptxwound healing [Autosaved].pptx
wound healing [Autosaved].pptxJiyaMuhammad1
 
Dentist in pune.(BDS. MDS) - Dr. Amit T. Suryawanshi. Wound healing in Dentis...
Dentist in pune.(BDS. MDS) - Dr. Amit T. Suryawanshi. Wound healing in Dentis...Dentist in pune.(BDS. MDS) - Dr. Amit T. Suryawanshi. Wound healing in Dentis...
Dentist in pune.(BDS. MDS) - Dr. Amit T. Suryawanshi. Wound healing in Dentis...All Good Things
 
Healing and wound contraction in inflammation
Healing and wound contraction in inflammationHealing and wound contraction in inflammation
Healing and wound contraction in inflammationArchana Mandava
 

Similar to Wound healing (20)

Woundhealing drneerajjain
Woundhealing drneerajjainWoundhealing drneerajjain
Woundhealing drneerajjain
 
Lect 6-wound healing
Lect 6-wound healingLect 6-wound healing
Lect 6-wound healing
 
Presentation1
Presentation1Presentation1
Presentation1
 
4.Wound Healing.pptx
4.Wound Healing.pptx4.Wound Healing.pptx
4.Wound Healing.pptx
 
Wound healing [including healing after periodontal therapy]
Wound healing [including healing after periodontal therapy]Wound healing [including healing after periodontal therapy]
Wound healing [including healing after periodontal therapy]
 
Wound healings
Wound healingsWound healings
Wound healings
 
Healing
HealingHealing
Healing
 
Wound healing
Wound healing Wound healing
Wound healing
 
TISSUE REPAIR.pptx
TISSUE REPAIR.pptxTISSUE REPAIR.pptx
TISSUE REPAIR.pptx
 
Inflammatory Principles & Athletic Rehab
Inflammatory Principles & Athletic RehabInflammatory Principles & Athletic Rehab
Inflammatory Principles & Athletic Rehab
 
Wound
WoundWound
Wound
 
Wound healing
Wound healingWound healing
Wound healing
 
wound healing [Autosaved].pptx
wound healing [Autosaved].pptxwound healing [Autosaved].pptx
wound healing [Autosaved].pptx
 
Dentist in pune.(BDS. MDS) - Dr. Amit T. Suryawanshi. Wound healing in Dentis...
Dentist in pune.(BDS. MDS) - Dr. Amit T. Suryawanshi. Wound healing in Dentis...Dentist in pune.(BDS. MDS) - Dr. Amit T. Suryawanshi. Wound healing in Dentis...
Dentist in pune.(BDS. MDS) - Dr. Amit T. Suryawanshi. Wound healing in Dentis...
 
Wound Healing & Wound Care
Wound Healing & Wound CareWound Healing & Wound Care
Wound Healing & Wound Care
 
woundhealing-2.pdf
woundhealing-2.pdfwoundhealing-2.pdf
woundhealing-2.pdf
 
WOUND HEALING AND ENDODONTICS
WOUND HEALING AND ENDODONTICSWOUND HEALING AND ENDODONTICS
WOUND HEALING AND ENDODONTICS
 
Wound healing
Wound healingWound healing
Wound healing
 
Healing and wound contraction in inflammation
Healing and wound contraction in inflammationHealing and wound contraction in inflammation
Healing and wound contraction in inflammation
 
Wound healing
Wound healingWound healing
Wound healing
 

More from Sakkar Chowdhury

Urinary Stress Incontinence
Urinary Stress IncontinenceUrinary Stress Incontinence
Urinary Stress IncontinenceSakkar Chowdhury
 
Traffic Engineering Fault Tolerance Using MPLS Routing - Optical Fiber Commun...
Traffic Engineering Fault Tolerance Using MPLS Routing - Optical Fiber Commun...Traffic Engineering Fault Tolerance Using MPLS Routing - Optical Fiber Commun...
Traffic Engineering Fault Tolerance Using MPLS Routing - Optical Fiber Commun...Sakkar Chowdhury
 
Pregnancy Related Dermatoses
Pregnancy Related DermatosesPregnancy Related Dermatoses
Pregnancy Related DermatosesSakkar Chowdhury
 
Grand Round (Medicine Unit)
Grand Round (Medicine Unit)Grand Round (Medicine Unit)
Grand Round (Medicine Unit)Sakkar Chowdhury
 
Simple Presentation On Raspberry pi
Simple Presentation On Raspberry piSimple Presentation On Raspberry pi
Simple Presentation On Raspberry piSakkar Chowdhury
 
Perioperative Management of Diabetes Mellitus
Perioperative Management  of Diabetes MellitusPerioperative Management  of Diabetes Mellitus
Perioperative Management of Diabetes MellitusSakkar Chowdhury
 

More from Sakkar Chowdhury (6)

Urinary Stress Incontinence
Urinary Stress IncontinenceUrinary Stress Incontinence
Urinary Stress Incontinence
 
Traffic Engineering Fault Tolerance Using MPLS Routing - Optical Fiber Commun...
Traffic Engineering Fault Tolerance Using MPLS Routing - Optical Fiber Commun...Traffic Engineering Fault Tolerance Using MPLS Routing - Optical Fiber Commun...
Traffic Engineering Fault Tolerance Using MPLS Routing - Optical Fiber Commun...
 
Pregnancy Related Dermatoses
Pregnancy Related DermatosesPregnancy Related Dermatoses
Pregnancy Related Dermatoses
 
Grand Round (Medicine Unit)
Grand Round (Medicine Unit)Grand Round (Medicine Unit)
Grand Round (Medicine Unit)
 
Simple Presentation On Raspberry pi
Simple Presentation On Raspberry piSimple Presentation On Raspberry pi
Simple Presentation On Raspberry pi
 
Perioperative Management of Diabetes Mellitus
Perioperative Management  of Diabetes MellitusPerioperative Management  of Diabetes Mellitus
Perioperative Management of Diabetes Mellitus
 

Recently uploaded

ANATOMICAL FAETURES OF BONES FOR NURSING STUDENTS .pptx
ANATOMICAL FAETURES OF BONES  FOR NURSING STUDENTS .pptxANATOMICAL FAETURES OF BONES  FOR NURSING STUDENTS .pptx
ANATOMICAL FAETURES OF BONES FOR NURSING STUDENTS .pptxWINCY THIRUMURUGAN
 
Clinical Research Informatics Year-in-Review 2024
Clinical Research Informatics Year-in-Review 2024Clinical Research Informatics Year-in-Review 2024
Clinical Research Informatics Year-in-Review 2024Peter Embi
 
Female Reproductive Physiology Before Pregnancy
Female Reproductive Physiology Before PregnancyFemale Reproductive Physiology Before Pregnancy
Female Reproductive Physiology Before PregnancyMedicoseAcademics
 
Different drug regularity bodies in different countries.
Different drug regularity bodies in different countries.Different drug regularity bodies in different countries.
Different drug regularity bodies in different countries.kishan singh tomar
 
Adenomyosis or Fibroid- making right diagnosis
Adenomyosis or Fibroid- making right diagnosisAdenomyosis or Fibroid- making right diagnosis
Adenomyosis or Fibroid- making right diagnosisSujoy Dasgupta
 
Trustworthiness of AI based predictions Aachen 2024
Trustworthiness of AI based predictions Aachen 2024Trustworthiness of AI based predictions Aachen 2024
Trustworthiness of AI based predictions Aachen 2024EwoutSteyerberg1
 
SGK RỐI LOẠN KALI MÁU CỰC KỲ QUAN TRỌNG.pdf
SGK RỐI LOẠN KALI MÁU CỰC KỲ QUAN TRỌNG.pdfSGK RỐI LOẠN KALI MÁU CỰC KỲ QUAN TRỌNG.pdf
SGK RỐI LOẠN KALI MÁU CỰC KỲ QUAN TRỌNG.pdfHongBiThi1
 
BENIGN BREAST DISEASE
BENIGN BREAST DISEASE BENIGN BREAST DISEASE
BENIGN BREAST DISEASE Mamatha Lakka
 
AORTIC DISSECTION and management of aortic dissection
AORTIC DISSECTION and management of aortic dissectionAORTIC DISSECTION and management of aortic dissection
AORTIC DISSECTION and management of aortic dissectiondrhanifmohdali
 
CPR.nursingoutlook.pdf , Bsc nursing student
CPR.nursingoutlook.pdf , Bsc nursing studentCPR.nursingoutlook.pdf , Bsc nursing student
CPR.nursingoutlook.pdf , Bsc nursing studentsaileshpanda05
 
Generative AI in Health Care a scoping review and a persoanl experience.
Generative AI in Health Care a scoping review and a persoanl experience.Generative AI in Health Care a scoping review and a persoanl experience.
Generative AI in Health Care a scoping review and a persoanl experience.Vaikunthan Rajaratnam
 
CONNECTIVE TISSUE (ANATOMY AND PHYSIOLOGY).pdf
CONNECTIVE TISSUE (ANATOMY AND PHYSIOLOGY).pdfCONNECTIVE TISSUE (ANATOMY AND PHYSIOLOGY).pdf
CONNECTIVE TISSUE (ANATOMY AND PHYSIOLOGY).pdfDolisha Warbi
 
Basic structure of hair and hair growth cycle.pptx
Basic structure of hair and hair growth cycle.pptxBasic structure of hair and hair growth cycle.pptx
Basic structure of hair and hair growth cycle.pptxkomalt2001
 
How to cure cirrhosis and chronic hepatitis naturally
How to cure cirrhosis and chronic hepatitis naturallyHow to cure cirrhosis and chronic hepatitis naturally
How to cure cirrhosis and chronic hepatitis naturallyZurück zum Ursprung
 
Red Blood Cells_anemia & polycythemia.pdf
Red Blood Cells_anemia & polycythemia.pdfRed Blood Cells_anemia & polycythemia.pdf
Red Blood Cells_anemia & polycythemia.pdfMedicoseAcademics
 
FDMA FLAP - The first dorsal metacarpal artery (FDMA) flap is used mainly for...
FDMA FLAP - The first dorsal metacarpal artery (FDMA) flap is used mainly for...FDMA FLAP - The first dorsal metacarpal artery (FDMA) flap is used mainly for...
FDMA FLAP - The first dorsal metacarpal artery (FDMA) flap is used mainly for...Shubhanshu Gaurav
 

Recently uploaded (20)

ANATOMICAL FAETURES OF BONES FOR NURSING STUDENTS .pptx
ANATOMICAL FAETURES OF BONES  FOR NURSING STUDENTS .pptxANATOMICAL FAETURES OF BONES  FOR NURSING STUDENTS .pptx
ANATOMICAL FAETURES OF BONES FOR NURSING STUDENTS .pptx
 
Clinical Research Informatics Year-in-Review 2024
Clinical Research Informatics Year-in-Review 2024Clinical Research Informatics Year-in-Review 2024
Clinical Research Informatics Year-in-Review 2024
 
Female Reproductive Physiology Before Pregnancy
Female Reproductive Physiology Before PregnancyFemale Reproductive Physiology Before Pregnancy
Female Reproductive Physiology Before Pregnancy
 
Different drug regularity bodies in different countries.
Different drug regularity bodies in different countries.Different drug regularity bodies in different countries.
Different drug regularity bodies in different countries.
 
Immune labs basics part 1 acute phase reactants ESR, CRP Ahmed Yehia Ismaeel,...
Immune labs basics part 1 acute phase reactants ESR, CRP Ahmed Yehia Ismaeel,...Immune labs basics part 1 acute phase reactants ESR, CRP Ahmed Yehia Ismaeel,...
Immune labs basics part 1 acute phase reactants ESR, CRP Ahmed Yehia Ismaeel,...
 
Adenomyosis or Fibroid- making right diagnosis
Adenomyosis or Fibroid- making right diagnosisAdenomyosis or Fibroid- making right diagnosis
Adenomyosis or Fibroid- making right diagnosis
 
Trustworthiness of AI based predictions Aachen 2024
Trustworthiness of AI based predictions Aachen 2024Trustworthiness of AI based predictions Aachen 2024
Trustworthiness of AI based predictions Aachen 2024
 
SGK RỐI LOẠN KALI MÁU CỰC KỲ QUAN TRỌNG.pdf
SGK RỐI LOẠN KALI MÁU CỰC KỲ QUAN TRỌNG.pdfSGK RỐI LOẠN KALI MÁU CỰC KỲ QUAN TRỌNG.pdf
SGK RỐI LOẠN KALI MÁU CỰC KỲ QUAN TRỌNG.pdf
 
BENIGN BREAST DISEASE
BENIGN BREAST DISEASE BENIGN BREAST DISEASE
BENIGN BREAST DISEASE
 
AORTIC DISSECTION and management of aortic dissection
AORTIC DISSECTION and management of aortic dissectionAORTIC DISSECTION and management of aortic dissection
AORTIC DISSECTION and management of aortic dissection
 
Biologic therapy ice breaking in rheumatology, Case based approach with appli...
Biologic therapy ice breaking in rheumatology, Case based approach with appli...Biologic therapy ice breaking in rheumatology, Case based approach with appli...
Biologic therapy ice breaking in rheumatology, Case based approach with appli...
 
CPR.nursingoutlook.pdf , Bsc nursing student
CPR.nursingoutlook.pdf , Bsc nursing studentCPR.nursingoutlook.pdf , Bsc nursing student
CPR.nursingoutlook.pdf , Bsc nursing student
 
Generative AI in Health Care a scoping review and a persoanl experience.
Generative AI in Health Care a scoping review and a persoanl experience.Generative AI in Health Care a scoping review and a persoanl experience.
Generative AI in Health Care a scoping review and a persoanl experience.
 
CONNECTIVE TISSUE (ANATOMY AND PHYSIOLOGY).pdf
CONNECTIVE TISSUE (ANATOMY AND PHYSIOLOGY).pdfCONNECTIVE TISSUE (ANATOMY AND PHYSIOLOGY).pdf
CONNECTIVE TISSUE (ANATOMY AND PHYSIOLOGY).pdf
 
GOUT UPDATE AHMED YEHIA 2024, case based approach with application of the lat...
GOUT UPDATE AHMED YEHIA 2024, case based approach with application of the lat...GOUT UPDATE AHMED YEHIA 2024, case based approach with application of the lat...
GOUT UPDATE AHMED YEHIA 2024, case based approach with application of the lat...
 
Basic structure of hair and hair growth cycle.pptx
Basic structure of hair and hair growth cycle.pptxBasic structure of hair and hair growth cycle.pptx
Basic structure of hair and hair growth cycle.pptx
 
How to cure cirrhosis and chronic hepatitis naturally
How to cure cirrhosis and chronic hepatitis naturallyHow to cure cirrhosis and chronic hepatitis naturally
How to cure cirrhosis and chronic hepatitis naturally
 
Red Blood Cells_anemia & polycythemia.pdf
Red Blood Cells_anemia & polycythemia.pdfRed Blood Cells_anemia & polycythemia.pdf
Red Blood Cells_anemia & polycythemia.pdf
 
Rheumatoid arthritis Part 1, case based approach with application of the late...
Rheumatoid arthritis Part 1, case based approach with application of the late...Rheumatoid arthritis Part 1, case based approach with application of the late...
Rheumatoid arthritis Part 1, case based approach with application of the late...
 
FDMA FLAP - The first dorsal metacarpal artery (FDMA) flap is used mainly for...
FDMA FLAP - The first dorsal metacarpal artery (FDMA) flap is used mainly for...FDMA FLAP - The first dorsal metacarpal artery (FDMA) flap is used mainly for...
FDMA FLAP - The first dorsal metacarpal artery (FDMA) flap is used mainly for...
 

Wound healing

  • 2. DEFINITION  Wound healing refers to the body’s replacement of destroyed tissue by living tissue.  Can be achieved by 2 processes: tissue regeneration &scar formation.  Dynamic balance between these 2 is different in different tissues.
  • 3. Introduction  During healing, a complex cascade of cellular events occur to achieve resurfacing, reconstitution and restoration of tensile strength of injured tissue.  Wound healing occurs in 3 phases 1. Inflammatory phase 2. Proliferative phase 3. Remodeling phase
  • 4. Stages of wound healing
  • 5. I. Inflammatory phase A. Immediate to 2-5 days B. Hemostasis 1. Vasoconstriction – damaged blood vessels constrict 2. Hemostasis is achieved by formation of platelet plug & activation of extrinsic & intrinsic clotting pathways. 3. Formation of a provisional fibrin matrix C. Recruitment of inflammatory cells into the wound by potent chemoattractants
  • 6. Early Events in Inflammation  Fibrin and fibronectin form a lattice that provides scaffold for migration of inflammatory, endothelial, and mesenchymal cells.  Neutrophilic infiltrate appears: removes dead tissue & prevent infection.  Monocytes/macrophages follow neutrophils: orchestrated production of growth factors & phagocytosis.
  • 7. Late Events in Inflammation  Entry of lymphocytes.  Appearance of mast cell
  • 8. II. Proliferative phase A. 2 days to 3 weeks B. Granulation tissue formation (composed of fibroblasts,macrophages and endothelial cell) C. Angiogenesis D. Contraction I. Wound edges pull together to reduce the defect E. Epithelialization I. Epithelial cells migrate across the new tissue to form a barrier between the wound and the environment
  • 9. Mesenchymal cell proliferation  Fibroblasts are the major mesenchymal cells involved in wound healing, although smooth muscle cells are also involved.  Macrophage products are chemotactic for fibroblasts. PDGF, EGF, TGF, IL-1, lymphocytes are as well.  Replacement of provisional fibrin matrix with type III collagen.
  • 10. Angiogenesis  Angiogenesis reconstructs vasculature in areas damaged by wounding, stimulated by high lactate levels, acidic pH, decreased O2 tension in tissues.  Recruitment & assembly of bone marrow derived progenitor cells by cytokines is the central theme.  EGF-1 is most potent angiogenic stimulant identified. Heparin is also an important as cofactor, TGF- alpha, beta, prostaglandins also stimulate.
  • 12. Epithelialization  Basal cell layer thickening, elongation, detachment & migration via interaction with ECM proteins via integrin mediators.  Generation of a provisional BM which includes fibronectin, collagens type 1 and 3  Epithelial cells proliferation contributes new cells to the monolayer. Contact inhibition when edges come together.
  • 13. III. Remodeling phase A. 3 weeks to 2 years B. New collagen forms which increases the tensile strength of the wound C. 19 types identified. Type 1(80-90%) most common, found in all tissue. The primary collagen in a healed wound. D. Type 3(10-20%) seen in early phases of wound healing. Type V smooth muscle, Types 2,11 cartilage, Type 4 in BM.
  • 14. Remodelling  The number of intra and intermolecular cross- links between collagen fibers increases dramatically.  A major contributor to the increase in wound breaking strength  Quantity of Type 3 collagen decreases replaced by Type 1 collagen  Remodeling continues for 12 months, so scar revision should not be done prematurely.
  • 15. Wound Contraction  Begins approximately 4-5 days after wounding by action of myofibroblasts.  Generally occurs in large surface wounds.  Represents centripetal movement of the wound edge towards the centre of the wound.  Maximal contraction occurs for 12-15 days, although it will continue longer if wound remains open.
  • 16. Wound contraction  The wound edges move toward each other at an average rate of 0.6 to .75 mm/day.  Wound contraction depends on laxity of tissues, so a buttock wound will contract faster than a wound on the scalp or pretibial area.  Wound shape also a factor, square is faster than circular.
  • 17. Wound Strength  Skin wounds  At the end of first week,wound strength is approximately 10% of unwounded skin  Wound strength increases rapidly over next 4 weeks and then slows down at approximately at third month,reaches a plataue at about 70- 80% of the tensile strength of unwounded skin  Scar tissue is ne ve r as stro ng as the o rig inal tissue !!
  • 18. Important Growth factors responsible for wound healing  Platelet derived growth factor:  Promotes migration and proliferation of fibroblasts  Is chemotactic for monocytes  Epidermal growth factor  Promotes growth of endothelial, epithelial cells and fibroblasts
  • 19. Growth factors in wound healing  Fibroblast growth factor:  Promotes synthesis of ECM proteins including fibronectin.  Chemotactic for fibroblasts and endothelial cells  Promotes angiogenesis  Vascular Endothelial Growth Factor (VEGF)  Angiogenesis  Macrophage derived growth factors  IL-1 and TNF  Promote proliferation of fibroblasts and endothelial cells.
  • 20. Wound healing  Wound healing is accomplished in one of the following two ways: 1. Healing by first intention (primary union) 2. Healing by second intention (secondary union)
  • 21. Healing by first intention (primary union)  Occurs in clean, incised wounds with good apposition of the edges – particularly planned surgical incisions  (clean wounds – no infections or foreign bodies)  The incision causes only focal disruption of epithelial basement membrane continuity and death of a relatively few epithelial and connective tissue cells.  As a result, epithelial regeneration predominates over fibrosis
  • 23. Immediate  The narrow incisional space rapidly fills with fibrin clotted blood  Dehydration at the surface produces a scab to cover and protect the healing repair site
  • 24. Within 24 hrs  Movement and proliferation of epithelial cells across the wound resulting in a thin, but continuous epithelial layer  Early inflammation close to the edges (neutrophils)
  • 25. 2-3 days  Neutrophils replaced by macrophages  Macrophages remove the blood clot  Proliferation of epithelial cells  Fibroblastic activity
  • 26. 10-14 days  Scab loose (aka dry clot)  Epithelial covering complete  Fibrous union of edges  Wound still weak  vascularization
  • 27. By the end of the first month  Scar comprises of a cellular connective tissue devoid of inflammatory infiltrate, covered by intact epidermis  Dermal appendages destroyed in the line of incision are permanently lost  Tensile strength of the wound increases and
  • 28. Healing by second intention (secondary union)  This occurs in open wounds, particularly when there has been significant loss of tissue, necrosis or large wounds with irregular margins  Regeneration of parenchymal cells cannot completely reconstitute the original architecture  Abundant granulation tissue grows in from the margin to complete the repair  Granulation tissues consists of:  ECM fibroblasts  Macrophages, neutrophils  New blood vessels
  • 29. Healing by second intention (secondary union) sequence of events
  • 30. Early
  • 32. 1 week Epithelial proliferation Capillary loops (granulations) Scab shed Loose connective Tissue formed by fibroblasts
  • 34. Months Full thickness of Epithelium restored Varying depth of Surface depression Thick collagenous Scar tissue becoming Less vascular
  • 36. Secondary union differs from primary union in several respects 1. inflammatory reaction is more intense 2. larger amounts of granulation tissue formation 3. larger scar 4. ***wound contraction  Myofibroblasts: modified fibroblasts with feature of SMC  defect significantly decreases in size as wound heals.
  • 37. Factors that influence healing  Classified as A. Systemic and B. Local
  • 38. Systemic Factors that Delay/Retard Wound Healing  Nutrition  Protein deficiency, Vitamin C deficiency  inhibit collagen synthesis  Zn deficiency (cofactor in type III collagenase)  Metabolic status  diabetes mellitus:  Susceptibility to infection caused by impaired circulation and increased glucose.  Circulatory status  inadequate blood supply  atherosclerosis, vascular defects  Hormones  glucocorticoids inhibit collagen synthesis, decrease inflammation
  • 39. Local Factors that Delay/Retard Wound Healing  Infection  most important cause of delayed wound healing  Persistent injury and inflammation  Mechanical factors  motion early in healing  Foreign material - like suture material and foreign bodies  Size, location & type of wound  wounds in ↑vascularized areas (face) heal faster than in poorly vasc areas (tendon, feet)  small wounds heal faster than larger  incisions faster than blunt trauma (contusions)
  • 40. Complications of wound healing 1. Deficient scar formation 2. Excessive formation of repair components 3. Exaggerated contraction
  • 41. Deficient scar formation Can lead to two types of complications: A. Wound Dehiscence (rupture of wound)  most common after abdominal surgery coughing, vomiting, B. Ulceration - defect in the continuity
  • 43. Excessive formation of repair components 1. Keloid / hypertrophic scar (excess collagen) 2. Exuberant granulation or proud flesh (excessive granulation tissue that protrudes above the level of the surrounding skin and impairs the growth of epithelium)
  • 44. Keloid / hypertrophic scar  Raised scars due to accumulation of excess amounts of collagen ( type III – type I)  Hypertrophic scars do not grow beyond the boundaries of the original wound  Keloids grow beyond the boundaries of the original wound (more serious)
  • 46. Exuberant granulation (proud flesh)  Excessive granulation tissue  Protrudes above surrounding skin  Prevents re -epithelialization
  • 47. Exaggerated contraction  deformation of surrounding tissue or wound  Can compromise the movement of joints.  most common on  palms, soles, anterior thorax following severe burns