It also remembers these encounters, so it can more effectively and rapidly battle the invader a second time with a massive, coordinated, immediate response to a second invasion 2. Immune response is mediated by lymphocytes , which are a type of white blood cell a. These, when intact, present a physical barrier a. Remember that these defenses also constitute the gut lining 2. These secretions also contain antimicrobial proteins, including lysozyme , which attacks cells walls of bacteria ii. Mucous is thick and viscous, trapping particles that encounter it iii.
Cilia line the trachea, and sweep microbes out of the lungs iv.
They migrate into infected tissues also ii. There they enlarge into macrophages iii. These are very large and very long-lived phagocytic cells 2. They surround parasites and discharge these enzymes into the body wall of the parasite 3. They are especially effective against viruses ii.