A dermatome is defined as:

A dermatome is defined as an area of skin that is supplied by a single spinal nerve root. This anatomical concept is critical in understanding how sensory information from the skin is mapped to the nervous system. Each spinal nerve has a specific section of skin that it innervates, and knowing the dermatomes helps in accurately diagnosing neurological issues, performing regional anesthesia effectively, and understanding pain patterns related to nerve injuries.

Understanding dermatomes is essential in clinical practice, especially in perinatal care, where it can help assess sensory loss or pain management techniques during labor and delivery. Although other options refer to relevant aspects of anesthesia and sensory awareness, they do not define what a dermatome specifically is.