Period 2 Chapter 43

2. Innate Immunity An Innate Immunity is an immunity that occurs naturally as a result of a person's genetic constitution. Innate immunities defend in a nonspecific way. Innate immunity is composed of two kinds of defenses, external and internal defenses . The external defenses include our skin, mucous and secretions. Bacteria and viruses cannot enter through the skin, meaning the skin works as a barrier. Mucous traps bacteria and expel them through the nose. Secretions, such as saliva and tears contain enzymes that kill bacteria. The Mucous traps microbes and the cilia expels mucous containing microbes upward into the pharynx. Mucus-producing cells (orange) Cilia (yellow) Tears and Saliva contain lysozyme, which is an enzyme that digests cell walls of many bacteria. The skin blocks bacteria and viruses from entering our bodies.

7. Role of the lymphatic system The lymphatic system produces and transports lymph fluid from tissues to the circulatory How does it aid in immunity? The lymphatic system produces lymphocytes which fights foreign molecules in the body .