The four primary functions of the skin are protection, thermoregulation, vitamin D synthesis, and sensory function.
- Protection: The skin acts as a barrier against physical damage, microorganisms, and harmful substances like UV radiation. Its outer layer, the epidermis, is composed of tightly packed cells, forming a tough, waterproof shield. [5, 7]
- Thermoregulation: The skin helps maintain a stable body temperature through sweating and blood vessel dilation or constriction. When the body gets hot, sweat evaporates, cooling the skin. When it's cold, blood vessels constrict, minimizing heat loss. [5, 7]
- Vitamin D Synthesis: When exposed to sunlight, the skin produces vitamin D, essential for calcium absorption and bone health. [5]
- Sensory Function: The skin contains sensory receptors that detect touch, pressure, temperature, and pain. These receptors transmit signals to the brain, allowing us to perceive our environment. [5]
