Skin System Wound Healing

Front 1

Wound Q:

List the 4 phases of wound healing

Back 1

1.Inflammatory Phase (2-5 days)
2. Migratory Phase (2-3 days after cut)
3. Proliferative Phase (5 days after wounding)
4. Late Phase Scar remodeling (3 weeks)

I Make People Laugh

Front 2

Wound Q:

You get cut...
Inflammatory Vascular Phase

Back 2

Inflamm. Vascular Phase:

HEMOSTASIS (stop the bleeding)
-VASOCONSTRICTION

then...Vasodilation
-increased permeability
-swelling from rush of fluid
signs: erythema, edema, heat, pain

Front 3

Wound Q:

Inflammatory Cellular Phase

Back 3

PHAGOCYTOSIS
-Macrophages and Neutrophils

Polymorphonuclear leukocytes
-Phagocytic
-Die within days

Monocyte
-Phagocytic (may transform into macrophages)
-Important in chronic inflammation-- engulf damaged tissues and digest them (lysosomes)

Front 4

Wound Q:

Migratory Phase

Back 4

ANGIOGENESIS is initiated
-Neovascularization

Epithelialization begins
-mitosis, daughter cells flatten, wound covered/repaired

Front 5

Wound Q:

Proliferative Phase

Back 5

FIBROPLASIA
-Undifferentiated, extravascular mesenchymal cells transform to fibroblasts stimulated by injury

-CONTRACTION

Front 6

Wound Q:

What makes collagen?

Back 6

-Manufactured by fibroblast

-Derives strength from cross-linking of strands

-Synthesis requires oxygen, ascorbic acid, and ferrous iron

Front 7

Wound Q:

What does the wound contraction?

Back 7

MYOFIBROBLASTS appear in the wound and contribute to the contraction. –resemble fibroblasts and may be derived from them.

Collagen has no contractile properties

Front 8

Wound Q:

Late Phase Scar Remodeling

Back 8

Continued turnover of collagen

Continues for 3weeks to two years
– but rate gain of tensile strength plateaus at 6 weeks after injury

(“no heavy lifting for 6 weeks”)

Front 9

Wound Q:

Goal of Wound Healing

Back 9

Goal is to provide adequate collagen for wound strength and integrity without excessive scarring—never reaches the tensile strength of unwounded tissue

Front 10

Wound Q:

Primary Intention for Wound Closure

Back 10

-Surgically clean wound.

-Sutured in period immediately after wounding

-Granulation tissue minimal

-Scarring minimal.

Front 11

Wound Q:

Examples of wounds that can be closed by primary intention

Back 11

Simple lacerations

Surgical incisions

Most dog bites

Kitchen knife wounds

Front 12

Wound Q:

Secondary Intention

Back 12

Loss of soft tissue.

Contaminated wound left open

Let the body heal itself

Considerable granulation tissue

Epithelialization and contraction.

Front 13

Wound Q:

Examples of wounds that can be closed by secondary intention

Back 13

Puncture wounds

Superficial abrasions

Most ulcers

Snake bites

Front 14

Wound Q:

Tertiary Intention

Back 14

Grossly contaminated wound

Left open for 4-5 days

Delayed primary closure

Front 15

Wound Q:

Examples of wounds that can be closed by tertiary intention

Back 15

Uncontrollable hemorrhage (Pack and pressure)

Acute wounds with questionably viable tissue or with foreign bodies
Wounds imbedded with road tar
Severely contused tissue

Human Bites!

Front 16

Wound Q:

Factors Affecting Wound Healing

Back 16

Nutrition- hard to affect
Vitamin deficiencies- vit C.
Trace element deficiencies- Zinc (balance)
Anemia and hemorrhage- need blood, yo.
Hypoxia- need o2 for proline/lysine hydroxylation
Steroids- Adrenocortical steroids inhibit ALL aspects of healing.
Anti-inflammatory drugs- inhibit prostaglandin synth, but normal doses are ok for wound healing.
Radiation- acute, intermediate, late; slows down healing.
Cytotoxic drugs- impairs wound healing
Diabetes

Front 17

Wound Q:

How does adrenocortical steroids inhibit all aspects of healing?

Back 17

-Moderates normal inflammatory response by inhibiting Fibroplasia and neovascularity

-Impairs epithelization and contraction

-can reverse by giving vit. A
-Ameliorates hypertrophic scars and keloids

Front 18

Wound Q:

Diabetes and wound healing

Back 18

Infection 5 times normal population

Impaired circulation due to vascular OCCLUSIVE disease

Hyperglycemia inhibits the inflammatory response

NEUROPATHY decreases sensation which exacerbates traumatic injuries

Need Antibiotics

Front 19

Wound Q:

Wound Closure

Back 19

Lidocaine (with/without epinepherine)

Control Bleeding

Flush wounds with normal saline (don’t use peroxide!, Don’t use iodine or povodine [betadine] in the wound!

Apply Betadine around the skin surface

Front 20

Wound Q:

2 types of sutures

Back 20

Absorbable:
-used internally (ex sew up tendons) where you can't take it out
-produces more inflammatory rxn (foreign body in the system)

Non-Absorbable:
-on the skin; less reactive, will have to eventually cut them out.