There are two main types of wound healing: primary and secondary. Primary healing occurs when the wound edges are close together and heal within 2-3 weeks. Secondary healing occurs when the wound edges cannot be approximated, resulting in more extensive granulation tissue formation and wound contraction over a longer period. The healing process involves hemostasis, inflammation, granulation, and remodeling phases across inflammation, proliferation, and maturation stages. Factors like infection, foreign bodies, nutrition, age, and diseases can impact wound healing.

2. WOUND
- is a type of physical trauma wherein the
skin is torn, cut or punctured (open
wound), or where blunt force trauma
causes a contusion (closed wound).
- a break in the continuity of any bodily
tissue due to violence is understood to
encompass any action of external
agency, including for example surgery.

3. HEALING
- act or process of curing or restoring the
wound.
- prevents the egress of irritants may
result in continued tissue disruption
and/or infection

4. WOUND HEALING
- comprises a fundamental biological
activity that involves both regenerative
and reparative activities.
- functions to restore the disrupted or
dead tissues to its normal state.

5.  * An ideal repair can be achieved in
tissues undergoing constant renewal
but is least effective in nerve &
muscle tissue.
 * Nerve undergo repair only when cell
bodies are intact.
 * Muscle tissue is repaired by fibrous
connective (scar) tissue, with
permanent loss of function.

6.  TYPES OF WOUND HEALING:
1. PRIMARY UNION
- healing by first intention
- there is narrow space between the
two cut surfaces of a wound
- healing is completed in 2-3 weeks

7. 2. SECONDARY UNION
- healing by second intention
- the two cut surfaces cannot be
appointed
- granulation tissue tend to heal the
wound from the base of wound
contraction.

8. 3. DELAYED UNION
- there is movement between the two
fractured surfaces
- infection
- poor blood supply
- pathogenic fractures

9. PHASES:
1. Hemostasis
2. Inflammation
3. Granulation
4. Remodelling
STAGES:
1. Inflammation
2. Proliferative
(Regeneration)
3. Maturation

10. Factors Affecting Wound Healing:
1. Infection – promotes further
inflammation & tissue destruction.
2. Foreign Bodies – stimulates
inflammation, thereby impending
the process of healing.

11. 3. Old Age – due to nutritional &
vascular deficiencies and
deteriorating immune system.
4. Nutritional Status – Vitamin C
deficiency has been associated
with impaired healing

12. 5. Concurrent Disease:
a. Vascular Disease – any disturbance
to the blood supply of a tissue
will result in delayed or impaired
wound healing.

13. b. Diabetes Mellitus – impaired blood
supply, impaired PMN
leukocytes function &
increased susceptibility to
microbial agents.

14. c. Uremia – because of disturbance
in inflammation response.
d. Blood Disease – hemorrhage at
the site of tissue damage,
resulting in large hematomas
that predispose secondary
microbial infection.

15.  PRIMARY
UNION
- Narrow space
between the 2 cut
surfaces.
- Undergoes
hemorrhage prior to
clotting.
 SECONDARY
UNION
- Large gap between
the 2 cut surfaces
that cannot be
appointed.
- Initial degree of
hemorrhage followed
by blood clot
formation.

16. PRIMARY
UNION
- Margins of wound
subsequently
undergo mild
inflammatory
reactions releasing
plasma and
polymorphonuclear
leukocytes into
incised space.
SECONDARY
UNION
- Mild short-lived acute
inflammatory
reactions occur in the
wound margins at the
same time.

17. PRIMARY
UNION
- After approximately 24
hours, capillary blood
vessels from wound
margins begin to bud
into the wound space
& then are followed
by both macrophages
and fibroblasts.
SECONDARY
UNION
- Granulation tissue
subsequently begins
to move into the
wound base & sides.
(These tissue
comprising capillary
buds, fibroblasts,
macrophages,
plasma cells &
lymphocytes.

18. PRIMARY
UNION
- Macrophages are
primarily associated
with phagocytosis of
the wound debris &
haemosiderin from
hemoglobin
breakdown.
SECONDARY
UNION
- Component cells
ensure the removal
of tissue debris,
these cells include
macrophages,
fibroblasts &
polymorphonuclear
leukocytes.

19. PRIMARY
UNION
- Fibroblasts begin to
form ground
substances.
SECONDARY
UNION
- Fibrous tissue is laid
down in the deeper
layers of the wound.
Granulation tissue
tends to heal the
wound from the base.

20. PRIMARY
UNION
- At the same time or a
little earlier, epithelial
cells from wound
margins undergo
mitosis & migrate
toward center of
wound thereby
forming a complete
but thin epithelial
covering. (SCAB)
SECONDARY
UNION
- Wound undergoes
contraction, primarily
reflecting fibroblastic
activity. Thus edges
of the wound is
closed by granulation
tissue & wound
contraction thereby
facilitating epithelial
migration & mitosis.
(SCAB)

21. PRIMARY
UNION
- Epithelium undergoes
progressive
maturation to regain
its full thickness.
SECONDARY
UNION
- Excessive granulation
is formed so that
recently healed
wound may appear
proud of the adjacent
tissue usually
resolved in a few
weeks.

22. PRIMARY
UNION
- Healing is usually
complete by 2-3
weeks.
- A longer period may
be required before
there is complete
restoration of the
tissue architecture.
SECONDARY
UNION
- Complex interactions
occur between
epithelia &
connective tissues:
CT formation – initially is essential
for the restoration of normal
epithelial continuity.
ET – subsequently may be
responsible for the formation of
connective tissue scar growth.

23. Secondary Healing differs from Primary
Healing in several aspects:
1. Large tissue defects initially have
more fibrin & more necrotic debris &
exudates that must be removed.
Inflammation reaction is more
intense.

24. 2. Much larger amount of granulation
tissue is formed.
3. Phenomenon of wound contraction.
That is, the defect is markedly
reduced from its original size.