[BI417] - Final Exam Guide - Ultimate 149 pages long Study Guide!
Document Summary
Elements of the immune system and their roles in defense. Immunology is the study of the physiological mechanisms that animals use to defend themselves from invasion by other organisms. Cells dedicated to defending the body (immune system) Protection against an invading pathogen: pathogen: disease causing agent. Immunity: second exposure to same pathogen, reduced or no symptoms=immunity. Human body is a great place for pathogens to live: nutrients, good temperature. Many organisms could live, feed, and reproduce if gone unchecked: (cid:862)eat at the sa(cid:373)e ta(cid:271)le(cid:863) tolera(cid:271)le a(cid:374)d depe(cid:374)de(cid:374)t o(cid:374) o(cid:374)e a(cid:374)other, eat the same nutrients we do. 1000 different microbial species live in a healthy human gut: (cid:1005)(cid:1004) l(cid:271)s of the (cid:271)od(cid:455)(cid:859)s (cid:449)eight, there are commensal species. Commensal bacteria want to stay in place, colonize in gut. Your gut microbiota helps you: process digested food, make vitamins, protect against disease. Outcompetes more dangerous bacteria from taking space in your gut: secretes ant-bacterial proteins.