MICR 2420 Lecture Notes - Lecture 11: Classical Complement Pathway, Alternative Complement Pathway, Lectin Pathway
Document Summary
We"re surrounded by microbes so how come we are not always getting sick. When barriers are breached : that"s when the immune system comes into play. What is the immune system: a complex system of organs, tissues, cells and cell products that work in concert to recognize and neutralize potentially pathogenic threats. Together the complex collection of cells and soluble proteins is capable of responding to almost any foreign molecular structure. Innate: may also be called non-adaptive or non-adaptive specific. Includes: physical barriers, chemical and cellular response, come into play if barriers are breached, adaptive. Contact with an infectious agent does not guarantee that a person will get sick. If number of infecting organisms is small and/or the immune system is effective, disease will not normally follow infection. To cause disease, a pathogen needs to: breach host defenses (open wound, getting through an orifice, invasion of cells, insect vectors, survive innate defense mechanisms, begin to multiply.