Module 1: Introduction to the Immune System Flashcards
Funtions of immune system
-discriminate and eliminate
Dysfunctions of immune system
-autoimmunity, hypersensitivity and immunodeficiency
Antigen definition
-foreign protein that includes an immune response
Antibody definition
-protein that is produced in response to, and countering, a specific antigen
Organization of the immune system
-lymphatic
-circulatory system
-immune system
Lymphatic system
-network of vessels that drains fluid (called lymph)
Circulatory system
-where lymph comes from and goes after being filtered
Immune system
-cells of the immune system travel between circulatory and lymphatic
Lymphoid organs and tissues
-bone marrow (made up of red and yellow marrow)
Bone marrow function
-filled w hematopoetic cells
Red marrow function
-site of hematopoesis
-site of b cell development
Yellow marrow function
-some leukocyte development
-produces fat and cartilage
Lymph nodes
-filters lymph, often first structure that foreign molecules encounter
MALT
-found at mucous membranes lining the digestive, respiratory and urogenital systems
-initiates immune responses to specific antigens encountered alone all mucosal surfaces
Spleen
-red pulp: filters the blood
-white pulp: site of development of immune responses against antigens found in the blood stream
Thymus
-site of t cell development and maturation
Branches of the immune system
-innate immune system
-adaptive immune system (humoural and cell-mediated)
Innate immunity
-1st line of defence
-physical soluble and cellular barriers
-min-hours
-recognize general patterns and not any one antigen
Adaptive immunity
-humoural (b cells) and cell mediated (t cells)
-takes days
-recognizes specific antigens
-results in immunological memory
Anebocyte
-oldest type of cell and is believed to have given rise to the phagocyte
Evolution of innate immunity
-found in vertebrates, invertebrates & plants
-fruit fly is often studied
Evolution of adaptive immunity
-only found in animals with a backbone, only more complex animals have a well developed system
Origin of immune cells
-every immune cell comes from pluripotent hematopoetic stem cells from the fetal liver and bone marrow
Hematopoetic stem cell
-self renewal: ability to divide itself and replace older cells
-pluripotent: ability to differentiate into several cell types, once a stem cell commits to its lineage it loses this ability
Myeloid progenitor (innate)
-granulocyte -> neutrophil, eosinophil, basophil, mast cell
-monocyte -> macrophage
-erythrocyte (red blood cell)
-thrombocyte (platelet)
Lymphoid progenitor (adaptive)
-B cell -> plasmocyte, memory B cell
-T cell -> helper T cell, cytotoxic T cell, memory T cell
-natural killer cells (innate)
Dendritic cells
-can arise from myeloid and lymphoid and are part of both innate and adaptive immunity
-capture and engluf antigens and present them to adaptive immune cells
-most common are lagerhans DC
Bacteria
-unicellular prokaryotic organisms that have no organized internal membranous structures
Cholera
-bacterial infection
-diarrheal illness
-eating or drinking foods that are contaminated
Viruses
-can infect a variety of organisms because they rely on the host cell for metabolism and reproduction, typically not considered organisms
Influenza
-viral infection
-fever, cough, sore throat etc
Fungi
-reproduce mainly by forming spores, and most commonly cause infection on the skin or in the lungs
Vaginal yeast infection
-fungal infection
-genital itching
-comes from an imbalance
Protozoa
-unicellular, heterotrophic eukaryotes which are very capable of rapid and flexible movements
Malaria
-protozoan infection
-mosquito borne
-fever, chills etc
-only from female mosquitos
Helminths
-parasitic worms which are simple invertebrates, some of which are infectious parasites
Schistosomiasis
-caused by parasitic worms
-inflammation, scarring, fever, chills etc
Prions
-new class of disease causing agent
-linked to degenerative disorders of the CNS
-happens because of misfolding of a protein
Bovine spongiform encephalopathy
-from prions
-mad cow disease
-originated from food fed to cows that contained sheep meat
-aggressive behaviour, trouble balancing, weight loss etc
Creutzfeldt-Jakob disease
-most common from prions
-exposure from infected individual or inheriting the gene
-loss of muscle coordination, impaired memory and decision making
Primary lymphoid organs
-thymus
-bone marrow
Secondary lymphoid organs
-spleen
-lymph nodes
-MALT
Primary lymphoid organs function
-site of lymphocyte maturation
-b-cell -> bone marrow
-t-cell -> thymus
Secondary lymphoid organs function
-site of lymphocyte activation into effector cell
