Inflammation and Wound Healing Quiz

Inflammation

• Acute inflammation is the body's initial response to injury or infection and is characterized by a short duration.
• Chronic inflammation occurs after a delay and is characterized by a longer duration.
• The main inflammatory cells in acute inflammation are neutrophils, in contrast to chronic inflammation where lymphocytes dominate.
• Chronic inflammation is likely to lead to more tissue damage and may have a fibrotic appearance.

Granulomas

• Chronic inflammation can lead to granuloma formation, which are areas of inflammation encased in a fibrous wall.
• Granuloma formation is the body's way of isolating and containing the irritant to prevent further spread.
• Granulomas can cause symptoms depending on their size and location, and may require further investigation.

Wound Healing

• Surgical incisions, trauma, pressure, friction, poor circulation, medical therapies, age, disease processes, heredity and nutrition can all lead to the development of wounds.
• Wounds can be intentional, unintentional, open, closed, clean, contaminated, or infected.

Describing Wounds

• Abrasion - a scrape
• Contusion - a bruise
• Incision - a clean cut
• Laceration - a jagged tear
• Penetrating wound - a wound where an object enters the body
• Puncture wound - a wound from a pointed object entering the body

Factors Influencing Tissue Healing

• The presence of foreign bodies and pathogens, the extent of damage, the body's response, and the health status of the individual all influence tissue healing.

Stages of Wound Healing

• Primary healing (first intention) refers to wounds with minimal tissue loss and edges that are close together.
• Secondary healing (second intention) refers to wounds with extensive tissue loss, often requiring a longer healing timeframe.
• Tertiary intention involves delayed closure of a wound that has been open for a period of time.

Wound Healing Stages (in detail)

• Inflammation (Primary Healing)
  • Begins within the first few hours after injury and includes inflammation, blood clot formation, and influx of white blood cells.
• Proliferation (Primary Healing)
  • Overlaps the inflammatory stage.
  • Epithelial cells begin to cover the wound.
  • New blood vessels form (angiogenesis).
  • Granulation tissue forms, which is a soft, red, and delicate tissue that fills in the wound.
  • Wound contraction occurs.
  • The blood clot becomes a scab which separates after 3-10 days.
• Maturation (Primary Healing)
  • Collage begins to degrade as it is produced.
  • Maturation begins when collagen production equals collagen degradation.
  • Can last for a year or more.
  • Stronger collagen is laid down.
  • Blood vessels are removed, and the scar gradually loses its redness.

Wound Healing Stages (in detail - Secondary Healing)

• Inflammation (Secondary Healing)
  • More intense than primary healing.
  • Necrotic tissue forms, which sloughs off the top of the wound.
  • Healing occurs by an indirect union of granulating surfaces.
• Proliferation (Secondary Healing)
  • Similar to primary healing, but more intense.
  • Increased activity of phagocytes.
  • Rich blood supply to reduce and prevent infection.
  • Granulation tissue forms at the base of the wound.
  • Fibroblasts convert to myofibroblasts, initiating contraction of the wound.
• Maturation (Secondary Healing)
  • Collagen is laid down horizontally.
  • Wound contraction is prominent.
  • Tissue is uneven, resulting in scar tissue.

Comparing Primary & Secondary Healing

• Primary healing: occurs in wounds with minimal tissue loss.
• Secondary healing: occurs in wounds with extensive tissue loss, leading to scarring and a longer healing time.

Tertiary Healing

• Delayed closure of a wound that has been open for a period of time, typically used for heavily contaminated wounds or wounds with ongoing infection.

Factors Affecting Wound Healing

• Local Factors:
  • Ischemia (reduced blood flow)
  • Foreign bodies
  • Infection
• Systemic Factors:
  • Age & gender
  • Hormones
  • Nutrition
  • Immunocompromised status
  • Stress
  • Diseases
  • Alcoholism
  • Medication
  • Obesity

Complications of Wound Healing

• Haemorrhage: excessive bleeding
• Infection: contamination of the wound by bacteria or other pathogens
• Dehiscence: splitting open of the wound
• Fistula: an abnormal connection between two organs or structures
• Keloid scar: raised, thick, and often disfiguring scar