BIOH 370 1st Edition Lecture 15Outline of Last Lecture Lymphatics and ImmunityI. Functions of the Lymphatic SystemII. Right vs. Left (thoracic) Lymph DuctsIII. LymphedemaIV. Formation and Flow of LymphV. Lymphatic CapillariesVI. Innate vs. Adaptive ImmunityOutline of Current Lecture Lymphatics and Immunity Day 2I. Development of the Immune System- Until BirthII. Innate Immunity: Nonspecific ImmunityIII. Internal Defenses: Second Line of Innate ImmunityIV. ComplementV. Development of Immune System After BirthVI. AntigenVII. Inflammation in ImmunityCurrent LectureLymphatics and Immunity Day 2I. Development of the Immune System- Until BirthThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Poorly developed at birth- Beginnings of the lymphatic vessels and main clusters of lymph nodes are apparent by the 5th week of embryonic developmento These arise from the budding of lymph sacs from developing veins- Lymphatic organs (except the thymus) arise from mesoderm- The thymus (endodermal origin) forms as an outgrowth of the pharynx - Except for the spleen and tonsils, lymphoid organs are poorly developed at birth- Breast milk= has lots of nutrients/stuff to help baby’s immunity – mom exposes herself to antigens=makes antibodies for babyII. Innate Immunity: Nonspecific ImmunityIII. Internal Defenses: Second Line of Innate ImmunityIV. Complement: contains soluble and membrane-bound factors that are highly regulated and work together to monitor and respond to microbial/ pathogenic conditions- Protein complexes can be used to find pathognes- Assemble proteins to make protein complexes- can form channels that can activated inflammation cascades- An innate mechanism of immune surveillance:o Monitors healthy cellso Opsonizes microbes/foreign cells so they can be phagocytosed; inducedcell lysiso Opsonizes apoptotic cells for phagocytosis; induces cell lysiso Detect and mark diseased cells for elimination because of insufficient regulation.- “shake and bake”= cover pathogens so that they can be identifiable and look more “ymmmy” for phagocytesV. Development of Immune System After Birth- Primary Lymphatic organs (stem cells divide and become immunocompetent, or mature)o Red bone marrowo Thymus- Secondary Lymphatic Organs (sites where immune responses occur)o Lymph nodeso Spleeno Lymphatic follicles (or nodules)- 8-10 colds/year/child for the first 2 years of their lifeVI. Antigen: ANY component that can be recognized by the immune system- can by ANYTHING that initiates an immune response- substances (can be proteins, glycolipids, carbohydrates, small proteins (haptens) that elicit an immune response.- Can be exogenous or endogenous- Has Epitopes on outside of antigen- changes in these direct specific responses1. Non-specific antigen: elicits a broad response because it activates the innate immune systemo Pathogen Associated Molecular Patterns (PAMPs): Molecular Patterns like gram negative LPS on bacteria like E. coli and Salmonella spp.o TLR3 and TLR7 recognize RNA2. Specific antigen: elicits a specific response by a set of immune cells and results in activation of the adaptive immune system and leads to immunological memoryo Recognizes one part of a protein expressed by a specific a pathogen thatis recognized by a specific receptor of a lymphocyte (evolves)VII. Inflammation in Immunity: nonspecific defensive response of the body to tissue damage and possible antigen exposure- Vasodilationo Histamine released by mast cells in tissues, basophils and platelets in bloodo Kinins: polypeptides induce vasodilationo Prostaglandins: lipids released y damaged cells and intensify effects of histamine and kininso Leukotrienes (LTs): basophils and mast cellso Complement: stimulate histamine release, attract PMNs by chemotaxis and promote phagocytosis- Emigration of phagocyteso PMNs and Monocytes (Macrophages)- Early inflammation increases vasodilation and increased vascular permeability:o Inflammatory chemicals cause1. Dilation of arterioles, resulting in hyperemia 2. Increased permeability of local capillaries and edema (leakage of exudate)o Exudate contains proteins, clotting factors, and antibodieso Functions of the surge of exudate1. Moves foreign material into lymphatic vessels2. Delivers clotting proteins to form a scaffold for repair and to isolate the
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