An adult old man gets burn injury to his hands. Over a few weeks, the burned skin heals without the need for skin grafting. The most critical factor responsible for the rapid healing in this case is -

The skin consists of two layers 1. Epidermis Most superficial layer of the skin. It is constantly replaced from the basal layer. 2. Dermis It is thicker than epidermis and supplies the strength and integrity to the skin It has a rich blood supply It contains adnexal structures i.e.→ Hair follicles, Sebaceous glands, Sweat glands. The importance of these adnexal structures is that they contain epithelial cells that can proliferate and can heal a partial thickness wound by epithelialisation. Superficial burns Involve only epidermis and superficial dermis The adnexal structures are left intact so they can heal by epithelialisation. Deep burns In deep burns, all the adnexal structures are lost so they can only heal by secondary intention with scarring. Presence of granulations simply indicate healing, one cannot tell whether it is healing by primary intention or by secondary intention.