Skin: Granulation tissue

1.    What pathological process is illustrated now?

Granulation formation, healing

2.    What type of tissue is present in the a) initial stages and b) later stages?

      a)       Endothelium of capillaries, inflammatory cells (macrophages, lymphocytes), fibroblasts (vascular granulation tissue)

      b)       Collagen, fibroblasts (fibrous granulation tissue)

3.    Describe the characteristic histopathological features in this slide.

Many new capillaries perpendicular to the surface in the granulation tissue.  Some inflammatory cells present, but it is normal, may not be signs of infection.  Some neutrophils, dead cells where the epidermis should have seen.  Area filled with fibroblasts.

4.    Number the following pathophysiological processes involved in would healing according to sequence:

      1.      Angiogenesis

      2.      Migration and proliferation of fibroblasts

      3.      Deposition of extracellular matrix

      4.      Tissue remodelling

5.    What�s the difference btw healing by 1^st and 2^nd intentions?  What does this case show?

1^st intention: wound edges in apposition, wound completely healed by 2^nd month

2^nd intention: arge tissue defect with blood cot and tissue debris.  Abundant granulation tissue grows to fill the wound.  Wound contraction caused by myofibroblasts, so defect markedly reduced from original size. Organisation and filling by granulation tissue take considerably longer.

6.    What will be the outcome in this case wrt the states of the a) epidermis, b) skin appendages, c) dermis, d) deeper soft tissue

a) reepithelisation � proliferation of epithelium at edges of the defect

b) Skin appendages (sweat glands, sebaceous gland) lost permanently

c) dermis interrupted by scar tissue

d) infiltration with scar tissue

7.    What factors can delay the healing process in this case?

Systemic factors:

      - nutritional status (protein and vit. C)

       - metabolic status (diabetes delay healing)

      - adequacy of blood supply

      - hormones (glucocorticoid therapy hinders inflammatory-reparative process)

Local factors:

      - infections: presence of inflammatory cells delay healing.

      - mechanical factors: increased abdominal pressure may rupture abdominal wounds.

      - foreign bodies: presence of foreign bodies induce a giant cell reaction - continued presence of inflammatory cells leads to delayed healing.

      - type of wound: wounds with large defects take longer to heal.

8.    When fully healed, skin wounds usually have tensile strength 70-80 % that of unwounded skin.

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Copyright � Joseph Ong 2003