Final answer:
The primary function of dermal blood vessels, in addition to nourishing epidermal cells, is thermoregulation, which involves regulating the body temperature by dilating or constricting to adapt to temperature changes.
Step-by-step explanation:
The dermal blood vessels serve multiple functions in the skin. They are crucial in nourishing epidermal cells and play an essential role in thermoregulation of the body. The vessels achieve this by either dilating or constricting to regulate heat loss or retention. This thermoregulatory function is an important aspect of the skin’s ability to maintain a stable internal environment, adapting to both internal and external temperature changes.
In addition to thermoregulation, the blood vessels in the dermis support other functions such as protection against pathogens and UV light, sensory reception through tactile receptors, and synthesis of Vitamin D when the skin is exposed to sunlight. Conversely, the dermis is not directly responsible for shock absorption; this function is attributed to the underlying hypodermis, which acts as a cushion and provides insulation.
Thus, of the options provided, thermoregulation is the primary function of dermal blood vessels in conjunction to nourishing the epidermal cells.