Lecture 7 Wound Healing Flashcards
Labiales cells
Continually divide and replicate throughout life, replacing cells (skin, hair, nails, mucosal cells)
Cancer cells are consider led because they are constantly dividing
Stable cells
Cells that are in resting stage until stimulated when they then enter the cell cycle
Ex: bone cells and hepatocytes (liver cells)
Permanent cells
Cells cannot regenerate and don’t enter cell cycle
Ex: neurons and cardiac myocytes
Adult “stem cells” can be stimulated to regenerate permanent cells
Stages of found healing (in order)
Hemostatis: initial respond
Inflammation: last up to 5 days
Proliferation: new tissue formation and may involve regeneration/repair with cat tissue but loss of fnc
Wound contraction and remodeling: up to 2 years
Factors affecting healing
Oxygenation-red. In COPD, atherosclerosis
Circulation- red. In elderly, CHF,DM, MI
Hydration status: red. In illness
Nutrition
Age: accelerated in young but red. In elderly
Immunity: red. In Im Unicom promised patients, infection, stress
Meds- cortisone, chemotherapy
Wound healing processes
1) Macrophages- dissolve clots, debris, add
2) collagen lattice forms
3) granulation tissue fills the wound
4) hypertrophic scar tissue overfills the wound
5) cicatrización (maturation) of wound may take 1-2 years. Collagen contracts and scar becomes lighter and smoother
Resolution
Returning injured tissues to the original structure and function
Repair
Replacement of destroyed tissues with scar tissue until they can be replaced with normal tissue
Scar tissue
Composed primary of collagen to restore the tensile strength of a tissue
Debridement
Cleaning up the dissolve the clots, microorganisms, ethrocytes and dead tissue cells
Types of wound healing
Primary, secondary, and tertiary intention
Primary intention
Wounds that heal under conditions of minimal tissue loss
A clean laceration that requires simple re-epithelialization when edges are approximated
Ex: surgical laceration
Secondary intention
Ones that require a great deal more tissue replacement
A wound with a large gap in tissue, some of the tissue has been gouged out
Ex: open wound, decubitus ulcer
Tertiary intention
Require more connective tissue (scar tissue) than one and two wounds
A wound with a large gap of missing tissue that has been contaminated and needs a drainage tube while healing
(Also called delayed primary intention)
Ex: abdominal wound left open to allow for drainage then later closed
Dysfunctional healing
Wounds may fail to close or may be open due to poor wound healing conditions
Nonunion, dehiscence, evisceration
Nonunion
Failure of adherence
Dehiscence
Wound edges separate exposing underlying tissues
Opening a wound’s suture line
Evisceration
Underlying for viscera are expose
Opening of wound with extrusion of tissue and organs
What else happens in Dysfunctional healing
Wounds may become infected and more tissue damage may result Abscess (walled off pocket of infection) sinus tract (narrow tunnel forms cellulitis (infection) Necrosis and gangrene may occur
Keloid
Hyperplasia of scar tissue
Contactares
Inflexible shrinkage of wound tissue that pulls the edges towards the center of the wound
Structure
And abnormal narrowing of tubular body passage from the formation of scar tissue
Fístulas
Abnormal connection between two epithelium-lined organs or vessels
Adhesions
Internal scar tissue between tissues or organs
Dysfunction during inflammation
Hemorrhage Fibrous adhesions Decreased blood volume Lack of nutrients Infection
Dysfunction during reconstructive phase
Impaired collage matrix assembly (keloid or hypertrophic scar)
Impaired epithelialization (anti inflammatory steroids, hypoxemia, nutritional def.
Wound disruption (dehiscence w/inc risk on infection)
Impaired contraction (contracture)
