1._Overview_of_the_Immune_System.ppt
- 1. Immune System Overview JL Torres, Ph.D. 1
- 2. Concept of Immunity Immunity (or resistance): host defenses (what you have) to ward off disease. Susceptibility: lack of resistance (what you don’t have) to a disease. 2
- 3. Synopsis of Immune System The immune system is a complex system composed of several types of mobile and fixed cells that interact in lymphoid tissue dispersed throughout the body The system is stimulated by the introduction of foreign material into the host; its function is the elimination of this material 3
- 4. 4 The Invaders . . . Bacteria Viruses Parasites such as fungi, protista, & worms Other – e.g., allergins, toxins worm trichura.jpg http://www.hhs.gov/asphep/presentation/images/bacteria.jpg http://www.skidmore.edu/academics/biology/plant_bio/lab13.FUNGI.html
- 5. Overview of Lymphatic System 1. Lymphatic system consists of lymph, lymph vessels, lymph nodes, and lymph tissue 2. Works with the circulatory system 3. Removes waste and excess fluid from the tissues 5
- 6. Lymph – the fluid in the tissues an extracellular fluid (ECF) similar to plasma ECF is found in several places in the body: body tissues (interstitial fluid) blood (plasma) lymphatic vessels (lymph) 6
- 7. 7 Located throughout the body in almost all tissues that have blood vessels Lymphatic Vessels/”Lymphatics”
- 8. 8 Small, open-ended lymph vessels Act like drainpipes Pick up lymph at tissues throughout the body Capillaries join together to form larger lymphatic vessels Lymphatic Capillaries
- 9. 9 Lymphatic vessels carry lymph Contractions of skeletal muscles against lymph vessels cause lymph to flow through vessels Vessels pass through lymph nodes Contain valves that keep the lymph flowing one way – towards the heart Lymphatic Vessels con’t.:
- 10. 10 Specialized lymphatic capillaries, called lacteals, located in area of small intestine a. Pick up digested fats or lipids b. When lymph is mixed with the lipids it is called chyle c. Lacteals transport the chyle to the blood stream through the thoracic duct Lacteals
- 11. 11 Popularly called “glands” Located all over the body usually in groups or clusters – principal groupings are located in the neck, armpits, chest, abdomen, pelvis, and groin Small, oval masses ranging in size from a pinhead to an almond nut Killing field for phagocytosed bacteria Lymph Nodes
- 12. 12 https://www.youtube.com/watch?v=MfALH zheD-g https://www.youtube.com/watch?v=QU6X MOo5UOE “What are Lymphatic Malformations? (Lymphatic System Part 2)” “What is the Lymphatic System? (Part 1: Anatomy and Physiology)” https://www.youtube.com/watch?v=o0- 1OknbO3M The lymphatic system | Health | Biology | FuseSchool
- 13. 13 As lymphatic vessels leave the lymph nodes, they continue to join together to form larger lymph vessels Eventually they drain into one of two lymphatic ducts: the right lymphatic duct or the thoracic duct Lymphatic Ducts
- 14. 14 Short tube Receives all the purified lymph from the right side of the head and neck, the right chest, and the right arm Empties into the right subclavian vein, returning the purified lymph to the blood Right Lymphatic Duct
- 15. 15 Much larger tube Drains the lymph from the rest of the body Empties into the left subclavian vein Enlarged pouchlike structure called the cisterna chyli is located at the start of the thoracic duct Thoracic Duct
- 16. 16 Serves as a storage area for purified lymph Receives chyle from the intestinal lacteals Cisterna Chyli
- 17. 17 Located throughout the body in addition to being in the lymph nodes Tonsils, spleen, and thymus are examples of lymphatic tissue Lymph Tissue
- 18. 18 Masses of lymph tissue Filter interstitial fluid Three pairs of tonsils Palatine tonsils on each side of the soft palate Pharyngeal tonsils (also called adenoids) located in the nasopharynx (upper part of the throat) Lingual tonsils on the back of the tongue Tonsils
- 19. 19 Stores erythrocytes to release into blood stream if excessive bleeding occurs Destroys thrombocytes or platelets Filters some metabolites and wastes from tissues http://www.youtube.com/watch?v=0CqWul ccLMo Spleen
- 20. 20 Mass of lymph tissue located in the center of the upper chest Atrophies or wastes away after puberty and is replaced by fat and connective tissue Thymus
- 21. 21 Functions during early life Produces antibodies Manufactures T lymphocytes to fight infection Function is taken over by lymph nodes after it atrophies http://www.youtube.com/watch?v=fFXQV- XJf3M Thymus
- 22. Lymphoid Cells, Tissues, and Organs Types of Lymphocytes: T CELLS (T lymphocytes) - attack foreign cells or body cells infected by viruses; T cells mature and divide in the thymus; T cells are responsible for cell-mediated immunity (meaning that the protection is directly from living cells) B CELLS (B lymphocytes) - responsible for antibody-mediated immunity (=humoral immunity); a percentage of circulating B lymphocytes mature into PLASMA CELLS; plasma cells produce and secrete antibodies which destroy antigens NK CELLS (natural killer cells) - attack foreign cells and cells infected with viruses and cancer cells 22
- 23. 23 Blood Cells
- 24. 24 Origin of Immune Cells Lymphoid tissue: Thymus, bone marrow, lymph nodes, tonsils T cells, B cells, NK cells Gut-associated lymphoid tissue (GALT) 40% of T cells are processed Myeloid Tissue: Red bone marrow, liver, spleen Macrophages
- 25. 25 Some Important Cells of the Immune System Innate Bridging Adaptive Neutrophil - primarily phagocytoses bacteria and other pathogens NK cells – destroy cells nonspecifically that are non-self (including virus-infected and cancer cells) Macrophage - phagocytoses bacteria, dead cells, etc., and secretes cytokines that affect many cell types. It plays an important role in bridging innate and adaptive immunity by activating T cells B cell - bears many membrane- bound immunoglubulins that act as B cell receptors. It secretes immunoglubulins as antibodies Dendritic cell - takes in foreign material, secretes cytokines, and activates T cells T cells – bears many identical membrane-bound T cell receptors. Some T cell secrete cytokines that regulate immune responses while others (CTL) kill tumor cells and virus- infected cells
- 26. 26 How coordination of immune system works: Cell Signaling Cytokines (Greek cyto-, cell; and -kinos, movement) are small cell- signaling protein molecules that are secreted by numerous cells used extensively in intercellular communication. - can be classified as proteins, peptides, or glycoproteins; the term "cytokine" encompasses a large and diverse family of regulators produced throughout the body by cells of diverse embryological origin. e.g., interleukins and TNF Chemokines (Greek -kinos, movement) are a family of small cytokines - derived from their ability to induce directed chemotaxis in nearby responsive cells; they are chemotactic cytokines
- 27. 27 Cytokines that regulate lymphocyte growth and activation Interleukin-2 Macrophage colony-stimulating factor (M-CSF)
- 28. 28 Cytokines that regulate lymphocyte growth and activation Interleukin-2 Macrophage colony-stimulating factor (M-CSF)
- 29. 29 Toll-like Receptors Toll-like receptors are protein receptors found in the plasma membrane of defensive cells that activate the innate immune system Toll-like receptors attach to Pathogen-Associated Molecular Patterns (PAMPs) of microbes: LPS Flagellin Lipoteichoic acid DNA of bacteria DNA and RNA to viruses Components of fungi and parasites
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- 31. 31 Acquired, specific (Adaptive) Third line of defense B cells, T cells and their effects Fever Antimicrobial proteins
- 32. 32 Features of Innate and Adaptive Immunity Feature Innate Immunity (1st and 2nd) Adaptive Immunity (3rd) Specificity for microbes Relatively low (not antigen specific) High (antigen specific) Specialization Low High Immunological Memory No Yes