The Immune System Pathogen a diseasecausing microorganism https

The Immune System Pathogen -a disease-causing microorganism

• https: //www. youtube. com/watch? v=p. Oz. Wo et. Mkq. Q&list=PLti. Og. IRVt 405 MBYm. OCuo t. H 7 o. GKy 9 JRu. Cv

• Your immune system functions by recognizing things as “self” or “non-self”, – ex. cells that belong in your body have identifying glycoproteins on their surface (“self”), cells/substances that do not belong in your body do not have those glycoproteins

The Immune System: Layers of Defense 1. Innate immunity - immediate but non-specific - includes: – external barriers – chemical barriers – cellular barriers

a) External barriers - our skin prevents pathogens from entering – sweat is antibiotic – mucus in our throats and noses traps microbes – tears are antibacterial – stomach acid kills microbes – all of these contain proteases that can cut up RNA and DNA (RNAses and DNAses)

b) chemical barriers: inflammation • swelling, increased circulation, localized rise in temperature • https: //www. youtube. com/watch? v=426 PDam 1 ey 4

c) Cellular barrier: the lymphatic system • A complex network of organs that work to rid the body of infection – Lymph, a transparent fluid that contains white blood cells (leukocytes), circulates through us – It filters out and engulfs foreign bodies (ex. bacteria, viruses) Macrophages: white blood cells that seek and destroy foreign cells

– Leukocytes (white blood cells) behave like independent single-celled organisms that identify and eliminate pathogens – They eliminate pathogens by either killing them through direct contact or engulfing and digesting them – https: //www. youtube. com/watch? v=0 Tv. Tyj 5 FAa. Q

When injury happens: • Neutrophils (inflammatory) are the first cells to respond to injury • Macrophages clean up debris • Mast cells induce swelling, warmth, and redness • All 3 types of cells summon more immune system cells

2. Adaptive/Acquired Immunity - activated by the innate response - involves many different types of immune cells https: //www. youtube. com/watch? v=RO 6 qmp Apy. DM

• Stronger than innate immunity • Our immune systems have an “immulogical memory” – The basis of vaccinations! • Pathogens are remembered based on their specific structures: antigens – antigens: anti-body gen-erators

• Adaptive immunity involves T cells and B cells – T-cells seek out and kill invaders

– B-cell produce antibodies towards antigens – Both produce memory cells that will allow the immune system to react FASTER and STRONGER next time, (hopefully) preventing spread of infection https: //www. youtube. com/watch? v=z 3 M 0 v. U 3 Dv 8 E

Passive versus Active Immunity a) Active immunity - body itself manufactures antibodies through fighting off a disease -provides lasting protection

b) Passive immunity • antibodies are introduced into bloodstream of an individual, given from mother to child during pregnancy and breast-feeding • short-term protection