The surface area of contact between the epidermis and the dermis is increased by structures called . This increased surface area allows for improved gas and nutrient exchange and waste removal by dermal blood vessels.

The correct answer is: Stratum basale or Stratum germinativum.

Explanation:

It is a part of the epidermis and is its innermost layer.It is located at the junction  of the inner dermal and outer epidermal layer.It remains attached to the basement membrane underneath by structures called hemidesmosomes.It forms finger-like projections into the underlying dermis, that increases its surface area which allow efficient exchange of nutrient and waste products.Touch-sensitive Merkel cells and melanin-producing melanocytes are interspersed in this layer.