BIOH 370 1st EditionExam # 2 Study Guide Lectures: 15 - 24Lecture 15 (March 4) Lymphatics and Immunity Day 1What are the functions of the lymphatic system?- Drains excess interstitial fluid- fluid left over from blood capillaries= about 3L/day= Once interstitial fluid is inside lymphatic system- now called lymph- Transports dietary lipids absorbed by the GI tract- Carries out immune responses-Use cytokines(specific hormones of lymphatic system) as helpersDescribe and Compare the Right Lymphatic vs. Left thoracic Lymph Ducts- Right lymphatic duct collects lymph from: Right jugular, right subclavian, right bronchomediastinal trunks- Attaches to the venus return at: right internal jugularvein and right subclavian vein- Thoracic (left lymphatic) duct collects lymph from: cisterna chili, right and left lumbar trunks, intestinal trunk, left jugular trunk, left subclavian trunk and, left bronchomediastinal trunk- Attaches to venus return at: Left internal jugular and left subclavian veins** ¾ is drained by thoracic duct (left side) , about ¼ is drained through right lymphatic ductDescribe Lymphedema and how it relates to lymph and interstitial fluid:-Lymphatic system allows a highway for metastasizing cancers- i.e. breast cancers usuallymove to lymph nodes when spread lymphatic ducts are so close- why feel axillary regions when checking for breast cancers- remove lymph nodes if cancer spreads to them= will lose interstitialfluid reuptake into blood= fluid build-up in body=lymphedemaLymphedema: build-up of interstitial fluid/lymph in the limbs(arms/legs) because notallowed to get back into blood flow (usually when lymph nodes get taken out due to cancers in the lymph nodes) * in one of the legs/arms and not the other because that specific lymph node on that side has the cancer/ or has been taken outDescribe the Formation and Flow of Lymph- use Frank Starling’s Law of Capillaries ** always a unidirectional flow of lymph- uses “trap doors”- Net Reabsorption into lymphatic Capillaries: Leukocytes, Lymph- Lymph is propelled by: Skeletal Muscle Pump, Respiratory pump- Does NOT use the cardiac muscle pump (separate)What are lymphatic capillaries and how do they relate to blood capillaries: greater permeability and larger diameter than blood capillaries- Interstitial fluid and cells can only flow IN to lymphatic capillaries- Absent from bones, teeth, bone marrow and the CNS- Lacteals: specialized lymph capillaries present in intestinal mucosa- Absorb digested fat and deliver fatty lymph (chyle) to the bloodCompare and Contrast Innate vs. Adaptive Immunity:- Innate Immunity: Nonspecific Immunity1. Skin and Mucous Membranes2. Internal Defenses (5)- Antimicrobials- Cells: phagocytes- lots of specific phagocytes- Complement system: like a “shake and bake”- can reorganize pathogens- Iron-binding proteins- used because pathogens like to use iron to grow, so we have ability to hold onto iron to prevent pathogens from using it- Antimicrobial proteins- Internal Defenses: Second Line of Innate Immunity- Complement: contains soluble and membrane-bound factors that are highly regulated and work together to monitor and respond to microbial/ pathogenic conditionsProtein complexes can be used to find pathogensAssemble proteins to make protein complexes- can form channels that can activated inflammation cascadesAn innate mechanism of immune surveillance:- Monitors healthy cells- Opsonizes microbes/foreign cells so they can be phagocytosed; inducedcell lysis- Opsonizes apoptotic cells for phagocytosis; induces cell lysis- 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 “yummy” for phagocytes- Adaptive Immunity- Antigen-specific lymphocytes with memory (i.e. IgG, IgM)Lecture 16 (March 6) Lymphatics and Immunity Day 2Describe the Development of the Immune System- Until Birth- Poorly developed at birth- Beginnings of the lymphatic vessels and main clusters of lymph nodes are apparent by the 5th week of embryonic development- 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 babyDevelopment of Immune System After Birth- Primary Lymphatic organs (stem cells divide and become immunocompetent, or mature)- Red bone marrow and thymus- Secondary Lymphatic Organs (sites where immune responses occur)- Lymph nodes, spleen, lymphatic follicles (or nodules)- 8-10 colds/year/child for the first 2 years of their lifeAntigen: 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)- 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 system- Pathogen Associated Molecular Patterns (PAMPs): Molecular Patterns like gram negative LPS on bacteria like E. coli and Salmonella spp.- 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 memory. Recognizes one part of a protein expressed by a specific a pathogen that is recognized by a specific receptor of a lymphocyte (evolves)Lecture 17 (March 9) Lymphatics and Immunity Day 3Explain Inflammation in Immunity and its effects/ what it uses: nonspecific defensive response of the body to tissue damage and possible antigen exposure- Vasodilation: Histamine released by mast cells in tissues, basophils and platelets in blood- Kinins: polypeptides induce vasodilation- Prostaglandins: lipids released y damaged cells and intensify effects of histamine and kinins- Leukotrienes (LTs): basophils and mast cells- Complement: stimulate histamine release, attract PMNs by chemotaxis and promote phagocytosis- Emigration of phagocytes- PMNs and Monocytes (Macrophages)- Early inflammation increases vasodilation and increased vascular permeability:- Inflammatory chemicals cause dilation of arterioles, resulting in hyperemia