The name of the largest organ in the human body is the skin. Covering the entire exterior of the body, the skin serves multiple vital functions, including protection against pathogens, regulation of body temperature, and sensory perception. It is composed of three main layers: the epidermis (the outer layer), the dermis (the middle layer containing blood vessels and nerves), and the hypodermis (the inner layer connected to underlying tissues). Skin also plays a crucial role in producing vitamin D in response to sunlight. As the body's first line of defense, maintaining healthy skin is essential for overall well-being.