Skin, hair, and nails
Skin is one of the body's organs .it covers the body's entire surface ,protecting it from injury and infection. it is waterproof and contains a dark pigment called melanin , which protects against damage from strong sunlight. people with dark skin have a lot of melanin ,people with light skin have less. skin helps control body temperature, for example by sweating shivering ,and special nerve endings in the skin, called sensory receptors, are designed to detect touch, heat, cold, and pain. skin also contains keratin, a tough protein present in hair and nails
