Wound Healing Process

Which type of wound involves non-traumatic wounds with contaminated entry into a viscus, but with minimal spillage?

What type of wound includes traumatic wounds or significant spillage from a viscus or acute inflammation?

Which category of wound involves non-traumatic wounds with no septic focus and no viscus opened?

What is included in the 'dirty' category of wounds?

Which of the following statements regarding inflammation is true?

Which cellular response is associated with streptococcal tonsillitis?

What is the nature of injury-induced vascular leakage?

What is the composition and location of viral endotoxin?

What is the main component involved in increasing wound strength during wound healing?

Which factor does not affect wound healing?

What causes scar contractures to be common on the flexor surfaces of joints?

Which type of abnormal scar extends beyond wound boundaries and does not regress spontaneously?

What makes children's scars take longer to settle and improve?

What are adhesion scars composed of?

Which cells have no capacity to regenerate?

What is the composition of granulation tissue?

During which stage does wound contraction occur?

What is the role of myofibroblasts in wound healing?

What is the immediate goal of haemostasis in wound healing?

Which cells are responsible for reducing infection in the wound?

What stimulates angiogenesis during wound healing?

Which stage involves the formation of scar tissue?

What is the role of collagen in wound healing?

Tissue healing in organs follows basic principles, including:
- Cells may be labile (have good capacity to regenerate), stable (have capacity to regenerate slowly), or permanent (no capacity to regenerate).
Tissue architecture is important, as complex arrangements cannot be reconstructed if destroyed (e.g. renal glomeruli).
Complete restitution occurs when part of a labile population of cells is damaged, such as minor skin abrasions.
Granulation tissue is the combination of capillary loops and myofibroblasts.
Organization is the process where specialized tissues are repaired by formation of mature connective tissue.
Wound contraction is mediated by myofibroblasts, reducing the tissue defect and forming a scar.
Four stages of wound healing:
- Haemostasis (immediate): Platelets aggregate and degranulate, releasing inflammatory mediators and achieving haemostasis.
- Inflammation (0-3 days): Vasodilation, increased capillary permeability, and inflammatory cells entering the wound, causing swelling, reducing infection, and debriding damaged tissue.
- Proliferation (3 days-3 weeks): Fibroblasts migrate, synthesize collagen, and cause wound contraction, and angiogenesis is stimulated.
- Maturation (3 weeks-1 year): Scar tissue is formed, collagen matures, and the wound is strengthened.
Myofibroblasts contain actin and cause wound contraction, reducing tissue defects.
Collagen is secreted at the same time to form a scar.
Haemostasis is achieved through platelet aggregation and the complement cascade.
Inflammatory cells, such as neutrophils and macrophages, enter the wound and cause swelling, reduce infection, and orchestrate fibroblast migration and collagen production.
Fibroblasts migrate into the wound, synthesize collagen, and cause wound contraction.
Angiogenesis is stimulated by hypoxia and cytokines, and granulation tissue forms.
Scar tissue is formed, collagen matures, and the wound is strengthened during the maturation stage.