WOUND
A break in the continuity of the
tissues
 Physical
 Compromisaed blood flow
 Crushing
 Desiccation
 Incision
 Irraiation
 Overcooling
 Overheating
CAUSES O...
WOUND REPAIR
EPITHELIALIZATION
 Injured epithelium has genetically programmed regenerative ability that allows it
to est...
e.g
 detrimental effect of process of c.inhibition controlling
epithelialization occurs when
o Opening is accidently made...
STAGES OF WOUND
HEALING
TREE BASIC STAGES:
 INFLAMMATORY STAGE (reactive phase)
 PROLIFREATIVE STAGE (regenarative or re...
INFLAMMATOY STAGE
o Tissue injury…lasts for 3-5 days
o TWO PHASES:
i. Vascular phase
ii. Cellular phase
VASCULAR PHASE
initial vasoconstriction of disrupted vessels…..blood coagulation
Histamine , prostaglandins elaborate by...
 Fibrin from plasma causes lymphatic obstruction ..accumulate in the
area of injury ….EDEMA
Signs of inflammation are
Redness
Swelling
Warmth and pain
Functio laesa
(fig)
CELLULAR PHASE
 Triggered by complement products .... act as chemotactic factors and cause
neutrophils…
o Margination ….
...
 Wd time lymphocytes accumulate at site of tissue injury
 B lymphocytes
o able to recognise antigenic material produce a...
 LAG phase
 During ds phase no significant gain in wound strength occurs ..little
collegen deposition
 Fibrin … materia...
PROLIFATIVE STAGE
The combined process of epithelialization , firoplasia and
angiogenesis accur in ordr to replace dead
a...
FIBROPLASTIC PHASE
 Strands of fibrin… form latticework…fibroblast can begin laying down ground
substance and tropocollag...
Fibroblasts deposit tropocollagen….
Collagen produced in xcessive amounts nd laid down in
haphazard manner …. Effectiven...
If Wound is placed under tension
o at the beginning of fibroplasia
o Near the end of fibroplasia
o At the end of fibropla...
REMODELLING STAGE
 Final stage….many of previous randomly laid collagen fibers are
destroyed as they are replaced by new ...
 Wd time … vascularity
…diminishes wound
erythema….Elastin is not replaced in
injured tissue…. loss of flexibility along
...
WOUND CONTRACTION
o Final process….
o edges of wound migrate toward eachothr
o In which edges are not placed in apposition...
FACTORS THAT IMPAIR
WOUND HEALING
 Foreign mateial
3 basic problems
i. Bacteria…..
ii. Nonbacterial foreign material…
iii...
 Necrotic tissue
causes 2 problems
i. serve as a barrier to ingrowth of reparative cells….
ii. Serves as a protected nich...
Ischemia
 Dec blood supply >>> tissue necrosis >>> lessen the delivery to
wound of antibodies, WBCs >>> inc the chances ...
Tension
 If sutures are used to pull tissues together forcefully, >>> ischemia of
tissues
 If sutures are removed too e...
 Edges of wound in which no
tissue loss are placed
 Wound in which edges are
closely reapproximated
 Healing occur more...
 Wound repair lessen amount of
re-epithelialization , collagen
deposition, contraction and remodelling
 Primary closure ...
HEALING BY
THIRD INTENTION
 Delayed closure of wound after a vaiable period of time for which it
been left open
 Healing...
THANK
YOU
ANY
QUESTION
?

OK
NOW UR QUIZ 
R U READY FOR THIS?
?????
 Causes of tissue damage
 Enumerate Stages of healing wd time
 Factors that impair wound healing
Causes of tissue damage and wound repair
Causes of tissue damage and wound repair
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Causes of tissue damage and wound repair

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Causes of tissue damage and wound repair

  1. 1. WOUND A break in the continuity of the tissues
  2. 2.  Physical  Compromisaed blood flow  Crushing  Desiccation  Incision  Irraiation  Overcooling  Overheating CAUSES OF TISSUE DAMAGE  Chemical  Agents wd inphysiologic pH  Agents wd unphysiologic tonicity  Proteases  Vasoconstrictors  Thrombogenic agents
  3. 3. WOUND REPAIR EPITHELIALIZATION  Injured epithelium has genetically programmed regenerative ability that allows it to establish its integrity  Free edges of epith cont. to migrate until it comes into contact with another free edge of epith  Abrasions (surface epith)
  4. 4. e.g  detrimental effect of process of c.inhibition controlling epithelialization occurs when o Opening is accidently made into maxillary sinus during tooth xtraction. o If epith of sinus wall and oral mucosa is injured ..it begins to proliferate in both areas….. creating OROANTRAL FISTULA
  5. 5. STAGES OF WOUND HEALING TREE BASIC STAGES:  INFLAMMATORY STAGE (reactive phase)  PROLIFREATIVE STAGE (regenarative or reparative) fibroplastic phase  REMODELLING STAGE (maturational phase)
  6. 6. INFLAMMATOY STAGE o Tissue injury…lasts for 3-5 days o TWO PHASES: i. Vascular phase ii. Cellular phase
  7. 7. VASCULAR PHASE initial vasoconstriction of disrupted vessels…..blood coagulation Histamine , prostaglandins elaborate by WBCs …vasodilation…which allows plasma to leak and leukocytes to migrate into interstitial tissues
  8. 8.  Fibrin from plasma causes lymphatic obstruction ..accumulate in the area of injury ….EDEMA
  9. 9. Signs of inflammation are Redness Swelling Warmth and pain Functio laesa (fig)
  10. 10. CELLULAR PHASE  Triggered by complement products .... act as chemotactic factors and cause neutrophils… o Margination …. o Diapedesis o Contact wd foreign material …. Degranulation o Lysosomal enzymes …destroy foreign materials ..digest necrotic tissue also aided by monocytes..macrophages
  11. 11.  Wd time lymphocytes accumulate at site of tissue injury  B lymphocytes o able to recognise antigenic material produce antibodies that assist in identifying foreign materials and interact wd complements to lyse foreign cells  T lymphocytes o Helper T cells o Suppressor T cells o Cytotoxic T cells
  12. 12.  LAG phase  During ds phase no significant gain in wound strength occurs ..little collegen deposition  Fibrin … material holding wound…..little tensile strength
  13. 13. PROLIFATIVE STAGE The combined process of epithelialization , firoplasia and angiogenesis accur in ordr to replace dead and missing tissue Lasts for 2 days to 3 weeks
  14. 14. FIBROPLASTIC PHASE  Strands of fibrin… form latticework…fibroblast can begin laying down ground substance and tropocollagen  Ground substance (mucopolysaccharides )…. Cement collagen fibers  Fibroblasts secrete fibronectin…helps  Stabilize fibrin  Assist in recognizing foreign material  Act as chemotactic factor for fibroblasts  Helps to guide macrophages along fibrin strands for phagocytosis of fibrin
  15. 15. Fibroblasts deposit tropocollagen…. Collagen produced in xcessive amounts nd laid down in haphazard manner …. Effectiveness of collagen to produce wound strength….rapidly inc during fibroplastic stage , which normally lasts for 2-3 weeks.
  16. 16. If Wound is placed under tension o at the beginning of fibroplasia o Near the end of fibroplasia o At the end of fibroplastic stage……stiff…..erythematous…able to wdstand 70-80% tension
  17. 17. REMODELLING STAGE  Final stage….many of previous randomly laid collagen fibers are destroyed as they are replaced by new collagen fibers, which are oriented to better resist tensile forces of wound  Slowly wound strength ..80-85%  Allows the Scar to soften…  Loss of edema…
  18. 18.  Wd time … vascularity …diminishes wound erythema….Elastin is not replaced in injured tissue…. loss of flexibility along scarred area(fig5)  Take 3 weeks to 2 years to complete
  19. 19. WOUND CONTRACTION o Final process…. o edges of wound migrate toward eachothr o In which edges are not placed in apposition , wound contracrion diminishes size of wound  Problems  third-degree …develop deforming nd debilitating contractures, if wounds are not replaced wd skin grafts  Can b lessened by placement of a layer of epith between d free edges of wound
  20. 20. FACTORS THAT IMPAIR WOUND HEALING  Foreign mateial 3 basic problems i. Bacteria….. ii. Nonbacterial foreign material… iii. Foeign material is often antigenic… That decreases fibroplasia  Infection
  21. 21.  Necrotic tissue causes 2 problems i. serve as a barrier to ingrowth of reparative cells…. ii. Serves as a protected niche for bacteria…. Include blood…..haematoma…….  Drugs  Nutritional problems  Low temp Distal aspect of xtremities (reduction of 1-1.5 C 2-3F)
  22. 22. Ischemia  Dec blood supply >>> tissue necrosis >>> lessen the delivery to wound of antibodies, WBCs >>> inc the chances of wound infection  dec delivery of O2 ….nutrients….  Caused by  Tight or incorrectly located sutures, improperly designed flaps, excessive external or internal pressure on wound, systemic hypotension, peripheral vascular disease and anaemia
  23. 23. Tension  If sutures are used to pull tissues together forcefully, >>> ischemia of tissues  If sutures are removed too early >>> reopen >>> heal with scar…w-contraction  If sutures are left in too long in attempt to overcome wound tension…spread open during remodelling stage…and tract into epith through which sutures ran will epithelialize and leave permanent disfiguring marks
  24. 24.  Edges of wound in which no tissue loss are placed  Wound in which edges are closely reapproximated  Healing occur more rapidly wd low risk of infection  wound repair wd minimum scar tissue  Tissue loss has occurred so A gap is left between edges of incision or laceration  Tissue loss prevents approximation of wound edges  Healing is slower  Produces more scar formation HEALING Primary Intention 2ndy Intention
  25. 25.  Wound repair lessen amount of re-epithelialization , collagen deposition, contraction and remodelling  Primary closure should b performed in 6-8 hr of trauma but vascular areas may b closed upto 24 hrs  e.g Well repaired lacerations or incisions, well-reduced bone fracture  A large amount of epithelial migration, collagen deposition, contraction and remodelling  Wound is left open and heals by formation of granulation tissue and contraction  e.g Extraction sockets, poorly reduced fractures, deep ulcers, large avulsive injuries of any soft tissue Primay Intention 2ndy Intention
  26. 26. HEALING BY THIRD INTENTION  Delayed closure of wound after a vaiable period of time for which it been left open  Healing of wounds through the use of tissue grafts to cover large wounds and bridge the gap between wound edges
  27. 27. THANK YOU
  28. 28. ANY QUESTION ? 
  29. 29. OK NOW UR QUIZ  R U READY FOR THIS? ?????
  30. 30.  Causes of tissue damage  Enumerate Stages of healing wd time  Factors that impair wound healing

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