Radioactive decay process is a type of process in which a less stable nuclei decomposes to a stable nuclei by releasing some radiations or particles like alpha particles , beta particles or gamma-radiations. The radioactive decay follows first order kinetics.
Alpha particles are helium nuclei, beta particles are electrons and gamma radiations are electromagnetic radiations which are released in the form of energy.
The integumentary system, which includes the skin, protects the body and regulates temperature/homeostasis. It also eliminates small amounts of waste, but it does not aid in movement directly.