American Academy of Professional Coders (AAPC) Practice Exam

What is the stratum Papillare composed of?

1. A thick, dense layer

2. A thin superficial layer interlocked with the epidermis

3. Flat, dead cells

4. A supportive connective tissue

The correct answer is: A thin superficial layer interlocked with the epidermis

The stratum papillare, also known as the papillary layer of the dermis, is characterized by its structure of a thin superficial layer interlocked with the epidermis. This layer is primarily composed of loose connective tissue that contains fine collagen and elastin fibers, allowing it to support and nourish the epidermis above. This papillary layer features dermal papillae, which are small, peg-like projections that interlock with the epidermis to enhance the strength of the junction between the two layers and increase surface area for nutrient exchange. These dermal papillae also form the basis for fingerprints, contributing to the unique patterns on human fingertips. Additionally, the papillary layer contains a rich supply of blood vessels and sensory receptors, contributing to temperature regulation and the sense of touch. This unique structure distinguishes it from the other layers mentioned in the question.