Immunology Chapter 1 Exam

Immunology Chapter 1 Exam Immunology the study of the physiological mechanisms that humans and other animals use to defend their bodies from invasion by other organisms Immune System cells that collectively are responsible for defense against infection Vaccination/Immunization prevention of disease by prior exposure to the infectious agent or a part of an infectious agent in a form that cannot cause disease Commensal Organisms microorganisms that live in a healthy human and do not cause disease Example of a Commensal Organism Gut Flora - aid in digestion - help prevent disease by out competing pathogenic microorganisms - antibiotic treatment kills much of the normal gut flora sometimes allowing opportunistic pathogens to establish infection Pathogen any organism with the potential to cause disease Opportunistic Pathogen organisms that cause disease only if the bodies defenses are weakened or if they get in the wrong place 4 Types of Pathogens 1. Bacteria 2. Viruses 3. Fungi 4. Parasites: including single celled protozoans and multicellular organisms (mainly worms) What two surfaces form barriers against infection? Skin and Mucosal Surfaces Epithelium composed of keratinized cells that forms an impermeable barrier Mucosa (mucosal surfaces) internal surfaces specialized for communication with the environment Where are chemical barriers to infection present? on Skin and Mucosa What are the 3 types of Chemical Barriers to infection? 1. Acids 2. Mucus 3. Defensins Chemical Barrier- Acid protect the skin, stomach and vagina Chemical Barrier- Mucus - thick fluid layer containing molecules to protect the body's cells from damage - also contain enzymes to kill pathogens Chemical Barrier- Defensin antimicrobial peptides secreted by epithelial cells Innate Immune Response 1st Line of Defense a pathogen encounters that can clear an infection. Two Parts of Innate Immune Response 1st: Recognition 2nd: Destruction/ Effector Mechanisms Effector Cells engulf pathogens, virus infected cells and complement coated pathogens Cytokines molecules secreted by innate immune cells and are responsible for initiating immune response 3 Activities of Cytokines 1. Cause Vasodilation 2. Immune Cell Recruitment 3. Immune Cell Activation Inflammation overall effect of the innate immune response - heat, pain, redness and swelling Adaptive Immune Response A branch of the immune system that becomes activated if a pathogen is not cleared by an innate immune response. Immunological/Long Term Memory -subsets of B- and T-lymphocytes will circulate in the body to quickly expand if a pathogen is encountered again. - response is quick with minimal disease. Lymphocytes - Adaptive Immune - white blood cells that adapt and respond to specific components of a pathogen Clonal Selection and Expansion - Adaptive Immune - adaptive immune cells proliferate and differentiate against the infecting pathogen The adaptive immune system focuses on a ? single pathogen Primary Immune Response 1st immune response against a pathogen Secondary Immune Response Immune response following subsequent infections by the same pathogen - more rapid of a response than the primary immune response. Adaptive Immunity is better understood than Innate Immunity Leukocytes common name for white blood cells - includes: lymphocytes, granulocytes and monocytes Immune system cells with different functions all derive from what type of cells? Hematopoietic Stem Cells Hematopoietic Stem Cells (HSC) the common progenitor or precursor of leukocytes/white blood cells - include erythrocytes (RBCs), megakaryocytes, platelets - bone marrow derived Self Renewal when HSC's divide to give further HSC's HSCs may differentiate into what 3 progenitors? 1. Myeloid Progenitor 2. Erythroid Progenitor 3. Common Lymphoid Progenitor