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Animal Physiology. Human Body Systems. Integumentary Skeletal Muscular Nervous Endocrine Cardiovascular Lymphatic Immune Respiratory Digestive Urinary Reproductive. Homeostasis. The maintenance of a steady state despite internal and external changes.
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Human Body Systems • Integumentary • Skeletal • Muscular • Nervous • Endocrine • Cardiovascular • Lymphatic • Immune • Respiratory • Digestive • Urinary • Reproductive
Homeostasis • The maintenance of a steady state despite internal and external changes. • All organisms maintain homeostasis to some extent.
Examples - How does your body respond to... • Cold weather • Starvation • Standing up • Exercise
Immunology • The immune system has a variety of defenses, just like a castle.
Cells and Molecules Involved • Neutrophil • Macrophage • Dendritic cell • Natural killer cell • Interferon • Complement system proteins • T cells • B cells • Antibodies • MHC molecule • Antigen
What is a pathogen? • Something that causes infectious disease in a host. • Most commonly - bacteria, viruses, protists, fungus, prions
Pathogens Disrupt Homeostasis... • Fever and shivering • Runny nose • Difficulty breathing • Blood composition • There are numerous ways in which pathogens disrupt homeostasis!
Innate Immunity (non-specific) • Barriers - skin, mucous membranes • Cellular - white blood cells (leukocytes) such as macrophages, neutrophils, dendritic cells, natural killer cells, and eosinophils • Proteins - interferon and the complement system proteins
Adaptive Immunity (specific) • Changes depending on number of pathogen exposures, hence the name - adaptive • Involves B cells and T cells that respond to specific antigens
Characteristics of Adaptive Immunity • Immense diversity of B cell and T cell receptors • Self-tolerance • Cell proliferation in response to an antigen encounter • Immunological memory
Humoral Immune Response • Clears the blood of pathogens • When the B cell with the matching receptor for the antigen is activated, it divides and produces plasma cells and memory cells • Plasma cells produce antibodies
Cell-Mediated Immune Response • Clears tissues of pathogens • When the cytotoxic T cell with the matching receptor for the antigen is activated, it divides and produces more cytotoxic T cells and memory T cells • Cytotoxic T cells inject chemicals into infected cells, causing them to lyse (break)
Primary vs Secondary Response • Primary = 10-17 days • Secondary = 2-7 days • Memory B and T cells make the secondary response faster
Immunizations • Also called vaccinations • They markedly increase the speed of the immune response • No research has shown correlation or causation between any vaccine and incidence of autism
HIV • HIV attacks Helper T cells • It severely hampers both the humoral response and cell mediated response