The skin protects the body through several layers that act as a barrier against pathogens, chemicals, physical injury, and UV radiation. It regulates temperature and acts as a sensory organ. The circulatory system delivers essential products and removes waste through blood circulation. The lymphatic system runs alongside and defends the body against microorganisms by carrying away bacteria and damaged tissues via lymph. When injured, the skin undergoes an inflammation response and healing process involving clotting, new cell growth, and maturation over time. Factors like nutrition, health, infection, and blood supply can affect wound healing.