性做久久久久久坡多野结衣-性做久久久久久久久浪潮-性欲影院-性影院-国产精品线路一线路二-国产精品兄妹在线观看麻豆

The immune system is composed of a complex network ofcells, tissues, and organs that function together as the body’sdefense against infectious organisms, diseases, and otherinvasive agents. Representing a duality of responsibilities,the immune system initiates the body’s quick and efficientresponse to harmful agents, while also distinguishing thesethreats from the body’s healthy cells and working to avoidautoimmunity, which is an attack against the host.