Injury or disease penetrating the skin to the level of the dermal papillae can affect which epidermal layer infrastructure?

When injury or disease penetrates the skin to the level of the dermal papillae, it primarily affects the basal layer, which is part of the stratum malpighii. The basal layer is the deepest layer of the epidermis and is crucial for the regeneration of skin cells. It contains keratinocytes that continuously divide and push older cells toward the surface. As these cells move up, they go through a process of keratinization, eventually forming the more superficial layers of the epidermis.

Injuries or diseases reaching this level can disrupt the normal function and health of skin cells, leading to impaired healing and potential scarring. This layer also houses melanocytes (responsible for pigmentation), and their function could be altered in the event of skin damage. Therefore, when the dermal papillae are involved, the infrastructure of the basal layer becomes vulnerable, affecting both the epidermis's structure and its overall function.