Wound healing

Question 1

chronic

Answer 1

“Chronic” indicates a long-term change involving fibrosis and scarring.

Question 2

Acute to chronic transition:

Answer 2

Acute inflammatory response cannot be resolved (stimulus not removed)
Interference with normal healing (factors that influence healing)

Question 3

chronic inflammation

Answer 3

Wound healing is an extension of chronic inflammation
Rheumatoid arthritis = auto immune disease where joints are attacked by immune cells, inflammation of membrane, swollen joint and chronically eroded cartilage and narrowing of joint space
* The cell population no longer involves lots of neutrophils.
Large inflammatory cells are likely macrophages.

Question 4

MACROPHAGES AND THEIR CYTOKINES PLAY CENTRAL ROLE IN CHRONIC INFLAMMATION

Answer 4

Macrophages become activated from blood monocytes.
They increase in size, have large lysosomes, have a greater ability to ingest and kill microbes and digest cell debris than neutrophils (they also can get rid of old neutrophils which have a much shorter life span).
They produce pro-fibrotic messenger molecular (cytokines) like tumour necrosis factor-alpha.

Question 5

Granulation tissue

Answer 5

is new connective tissue and new blood vessels (process of angiogenesis) that form in a wound during the healing process.
Granulation tissue is able to fill wounds of almost any size.
The cellular component is made up of new and active fibroblasts (myofibroblasts) and macrophages

Question 6

Wound healing is complex and orderly: process

Answer 6

• Induction of acute inflammatory response
• Migration and proliferation of normal tissue cells (regeneration)
• Building wound strength with fibrosis: proliferation of connective tissue cells, synthesis of ECM proteins (collagen), remodeling. Granulation tissue builds wound strength (macrophages, fibroblasts, new capillaries, collagen)
• Resolution (no scar) or organisation (scarring)

Question 7

** Components of granulation tissue

Answer 7

macrophages, fibroblasts, new capillaries, collagen

Question 8

Granulation tissue

Growth factors involved

Answer 8

Epidermal growth factor (EGF) - stimulates regeneration of platelet
Platelet derived growth factor (PDGF) - stimulates activity of fibroblasts and macrophages
Transforming growth factor-beta (TGF-beta) - stimulates fibroblasts
Fibroblast growth factor (FGF)

• Autocrine, paracrine
  and endocrine action.

Question 9

Healing - first 24 hrs

Answer 9

huge nutrifil influx to stimulate repair process and clot to stop bleeding