A 24 year old delivery driver is involved in an accident and sustains a wide abrasion over his left elbow. The abrasion results in the total loss of epidermis over a large area of his left arm,but one month later, the abrasion has healed, with regrowth of the epidermis. Which of the following mechanisms accounts for the restoration of the epidermis over the abraded area?
The dermis contains skin appendages (e.g., hair follicles) that contain epithelial stem cells. In the process of healing a large area where the epidermis has been lost, but the dermis is intact, re-epithelialization occurs by ingrowth of epidermal cells from the underlying skin appendages, as well as from the intact epidermis along the wound edges.None of the other cell types are known to directly contribute to the regeneration of epidermis over abraded skin.
Growth of epidermis from hair follicles and sweat glands in the dermis
Migration of endothelial cells from newly grown capillaries
Transformation of dermal fibroblasts into epidermal cells
Transformation of macrophages into epidermal cells