POWERPOINT ® LECTURE SLIDE PRESENTATION by ZARA OAKES, MS, The University of Texas at Austin Additional Text by J Padilla exclusively for physiology at ECC Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings HUMAN PHYSIOLOGY AN INTEGRATED APPROACH FOURTH EDITION DEE UNGLAUB SILVERTHORN UNIT 4 24& 15 The Lymphatic & Immune System

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Lymphatic System  Fluid leaks out of capillaries onto tissues- it is now called lymph  Lymphatic system returns fluid and proteins to circulatory system  Picks up fat absorbed at intestines and transfers it to circulatory system  Servs as filter for pathogens

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 15-18b Fluid Exchange at a Capillary (Independent Study)

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure Lymphatic System  lymph nodes are organs that filter lymph fluid before it has an opportunity to enter back into the blood vessels. They also collect antigens carried by lymph so they can be engulfed by macrophages and presented to lymphocytes.

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings spleen- largest lymphoid organ, it is almost the size of the heart. It removes blood born pathogens and aged/damaged RBCs. It also stores platelets. It has areas identified as white (lymphoid tissue) and red pulp (vacular tissue).

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Lymphatic tissues contains lymphocytes and assist the body in fighting infections. They are located in areas that are most likely to be exposed to antigen Lymphatic tissues house lymphocytes that are either maturing or ready to respond The lymphatic systems also prevents swelling.

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Edema  Two causes  Inadequate drainage of lymph  Filtration far greater than absorption  Disruption of balance between filtration and absorption  Increase in hydrostatic pressure  Decrease in plasma protein concentration  Increase in interstitial proteins quiz/images/primedema.jpg

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Immune System: Functions  Protects from pathogens and foreign molecules (antigen)  Parasites  Fungus  Protozoans  Bacteria  Viruses  Removes dead or damaged cells  Attempts to recognize and remove abnormal cells developing from mutation (ex Cancer) or viral infections  May respond to incorrectly, over respond, or not respond  Autoimmune disease (Type 1 diabetes)  Allergies (respond to non-harmful molecules)  Immunodeficiency disease (AIDS)

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24-4 Key Cells of the Immune System

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Body Defenses: Two Lines  First Line of defense  Physical and chemical barrier  Skin, epithelial linings, and cilia  Acids, mucous, and lysozymes  Second Line of Defense  Immune responses include:  Detect and identify invader/foreign cells  Communicate, alarm, and recruit immune cells  Coordinate response among all participants  Suppress or destroy invader  Types of Immunity  Innate, non-specific, immediate response  Responses that don’t retain memory  Guided by granulocytes and macrophages  Acquired; attack a specific pathogen (antigen)  Retain memory  Guided by lymphocytes and antigen presenting cells

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Overview of Immunity Immune System Innate Immunity Acquired Immunity Physical Barriers Cellular & Chemical Response Actively Acquired * Infection * Vaccination Actively Acquired * Infection * Vaccination Passively Acquired * Mother * Serum Passively Acquired * Mother * Serum Antigen Specific= APC & MHC Humoral Immunity * B-cells Humoral Immunity * B-cells Cell- Mediated Immunity * T- Lymphocytes *Natural Killer Cells Cell- Mediated Immunity * T- Lymphocytes *Natural Killer Cells * Integument * Fluid secretion * Integument * Fluid secretion Granulocytes Macrophages Inflammation Fever Compliment Opsonins Granulocytes Macrophages Inflammation Fever Compliment Opsonins

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Innate Immunity: Inflammatory Response

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Innate Immunity: Inflammatory Response  Attract immune cells and chemical mediators to site of infection  Produce physical barrier to prevent infection from spreading  Promote tissue repair  Histamines from mast cells  Swelling, edema, vasodilation  Interleukins  Fever, blood vessels more permeable to white blood cells and proteins, acute-phase proteins  Bradykinin  Pain and swelling  Complement cascade  Membrane attack complex

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24-8 Inflammatory Response: Players Action of a membrane attack complex

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Macrophages Present antigen  Phagocytosis and digestion of foreign cell allows macrophates to present antigen  Lysosomal enzymes digest pathogens that have been enclosed in phagosomes  Antigen presentation activates lymphocytes

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Acquired Immunity: Antigen-Specific  T lymphocytes  Helper T cells  Cytotoxic T cells  B lymphocytes  Plasma cells  Memory cells  NK cells  Naïve lymphocytes under go clonal expansion once activated.  Effector cells- release antibodies or cytokines  Memory cells-assist in faster subsequent responses

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Acquired Immunity: Antigen-Specific  B lymphocytes: Humoral Immunity  Immunoglobulins  Plasma and memory cells  Primary and secondary response  How clonal expansion leads to immunologic memory

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure Plasma Cells: Antibody Structure Antibodies (Ab) bind antigen (ag) One Ab per Ag One B-cell per Ab type Antibodies= (Ig) immunoglobulins Five classes: IgG, IgA, IgE, IgM, IgD Light and heavy chain Antibodies (Ab) bind antigen (ag) One Ab per Ag One B-cell per Ab type Antibodies= (Ig) immunoglobulins Five classes: IgG, IgA, IgE, IgM, IgD Light and heavy chain

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Functions of Antibodies Figure 24-13, steps 1–6 Activates B lymphocytes Antigen binds to antibody Antigen binding site Bacterial toxins Activates antibody- dependent cellular activity Acts as opsonins Causes antigen clumping and inactivation of bacterial toxins Triggers mast cell degranulation Memory cells Plasma cells NK cell or eosinophil Antibody Secrete antibodies Activates complement Enhanced phagocytosis Adapted from Jo Kuby, Immunology 2e (New York: W. H. Freeman, 1994)

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure T Lymphocytes : Cell-Mediated Activation of T lymphocytes  T cell receptors  Cell activated by antigen  Major histocompatibility complex (MHC) incorporates antigen fragments  MHC class I = Cytotoxic T cells  MHC class II =Helper T cells

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure T Lymphocytes: Cell-Mediated Roles of T lymphocytes and NK cells in cell-mediated immunity. NK cells eliminate virus-infected and tumor cells and secrete interferons to prevent viral replication and active macrophages

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Defenses against Bacteria

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure Defenses against Viruses Viruses may be neutralized by antibodies present from previous infections or by attacking the infected cell.

Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Allergic Responses Figure First exposure Sensitization & activation, clonal expansion of B cells, they form Ab & memory cells Re-exposure Many antibodies, activated T cells, intensified response, inflammation First exposure Sensitization & activation, clonal expansion of B cells, they form Ab & memory cells Re-exposure Many antibodies, activated T cells, intensified response, inflammation