Wound Healing

Keloid is excess production of scar tissue that is out of proportion to the wound

Explanation -
Immediately after an injury the narrow incisional space is filled with clotted blood containing fibrin and blood cells. 

Within 24 hours, Neutrophil appear at the margin of the incision moving towards the fibrin clot.

Explanation :
Local factor influence wound healing -
Local blood supply
Denervation
Local infection
Foreign body
Haematoma
Necrotic tissue
Mechanical stress
Protection ( dressing)
Surgical techniques
Types of tissues

Complication of wound healing due to deficient scar formation is wound dehiscence

Exuberant scars that recur after excision are called desmoids

[Robbins 9th 71]

Explanation -
Granulation tissue found in :
Wound
Ulcer
Sinus tract
Pyogenic granuloma 
Fistula
Wall of abscess
Granulation tissue absent in :
All types of granulomatous inflammation except pyogenic granuloma 
Scar
Necrosis
Organizing haematoma
Congestion.

Granulation tissue easily bleeds on touch due to rupture of new capillaries

Vit A essential for epithelialization, Vit C essential for collagen synthesise , VitD easential for bone formation