1 / 21

The immune system

The immune system. Andrea Duncan. Non-specific defenses. (innate). Physical barriers. Skin and mucous membranes Bark. Biochemical barriers. Stomach Saliva, sweat, tears Fever inflammation Phagocytes: Consume foreign or aged materials in bloodstream and lymphatic system

ellette
Télécharger la présentation

The immune system

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The immune system Andrea Duncan

  2. Non-specific defenses (innate)

  3. Physical barriers • Skin and mucous membranes • Bark

  4. Biochemical barriers • Stomach • Saliva, sweat, tears • Fever • inflammation • Phagocytes: Consume foreign or aged materials in bloodstream and lymphatic system • Leukocyte (white blood cell)—natural killer cell, kills virus-infected cells

  5. Specific defenses (adaptive)

  6. Components of blood • erythrocytes (red blood cells) • leukocytes (white blood cells) • platelets

  7. Leukocytes • Granulocytes • Eosinophils—focus on parasites of the skin and lungs • Neutrophils—Most common leukocyte, short-lived, respond to inflammation in an injury (chemotaxis), macrophagial and cytotoxic to foreign bodies • Basophils—cause inflammation and produce histamine • Monocytes—turn into specified macrophages, ingest dead neutrophils

  8. Leukocytes continued • Lymphocytes • Develop in primary lymphoid organs and live in secondary lymphoid organs (lymph nodes, spleen, appendix, tonsils, intestinal tract, under skin) • Bone marrow—produces stem cells, which differentiate into different types of blood cells • Travel through both blood and lymphatic systems, pass from blood through lymph nodes, pass from lymphatic system through thoracic duct • Two types

  9. B cells • Produced and Develop in bone marrow • Antibody-mediated immune response • Produce antibodies (protein) when they encounter an antigen

  10. B cell Antibodies • Each B-cell is covered with the same antibody, therefore can only bind to that specific antigen • Structure: 4 polypeptide chains, two identical sides, 2 binding sites; many different amino acid sequences on binding sites for different purposes, different combinations of antibody chains account for more types of antibodies than there are genes (antibody diversity) • Antibodies mark antigen for non-specific destruction by binding to them • May bind multiple antigens together for easy destruction, or mark them for other cells to destroy—complement system

  11. Once bound to an antigen, cell multiplies into 2 types of cell: • Plasma cells • Produce more of the same antibody to fight specific antigen, short lifespan • Memory B cells • Exist to respond if antigen returns to body, less of these made

  12. T cells • Produced in bone marrow, Develop in thymus (just above heart) • Cell-mediated immune response • Produce chemicals that produce and maintain an immune response • T-cell receptors on surface • activate when parts of an antigen are recognized on an MHC protein—both occur on the surface of a cell that is infected by a virus • Differentiate between foreign and self by recognizing HLA molecules on a cell…all cells of the body except for red blood cells have a different combination of these molecules on their surface—tolerance • Organ transplant—more successful if HLAs of donor and recipient are mostly identical (lesser immune response)

  13. Types of T cell: • CTLs—Cytotoxic T lymphocytes • Limit viral infections by killing virus-infected cells • TH—Helper T cells • Produce cytokines, which stimulate other lymphocytes to reproduce • Speeds up production of B plasma cells, which in turn boosts release of specific antibodies into the bloodstream • Th1—stimulate cytotoxic response • Th2—stimulate antibody response

  14. video

  15. Immune memory • Long-term resistance to repeat offenders—clonal selection • Primary immune response—when first exposed to antigen • Secondary immune response—reaction using memory B cells • Antiviral drugs—prevent virus from reproducing • Antibiotics—attack bacteria

  16. Vaccines • dead or weakened organisms that make body create immunity without organism actually getting infected • Inactivated=unable to reproduce • Attenuated=unable to cause disease • Chicken pox, smallpox, measles, mumps, Hepatitis A and B, rabies, rubella, typhoid, tuberculosis • Edward Jenner—cured smallpox • Louis Pasteur—vaccine for rabies and others • Currently research occurring for a vaccine for AIDS

  17. Immune system malfunctions • Immune suppression • Medication and illegal drugs • Infectious agents—HIV • Immune hyperactivity • Allergic reactions—poison ivy, metallic, asthma, seasonal allergies • Autoimmunity • Body attacks its own cells—rheumatoid arthritis, MS, diabetes • Caused by combination of genetic susceptibility and environmental factors • Leukemia • Lymphocytes turn cancerous, malfunctioning lymphocytes crowd out normal ones and decrease immune system • May break off into bloodstream or bone marrow

  18. HIV/AIDS • HIV=human immunodeficiency virus • AIDS=acquired immunodeficiency syndrome

  19. HIV/AIDS • Affects helper T cells, sometimes macrophages and nerve cells • Attachment site: CD4 protein, attaching protein: gp 120 • Viral infection…(steps review?) • Result: decrease in helper T cells, greatly weakens immune system; constant war between helper T cells and HIV

  20. Why no cure? • Retrovirus—RNA material, mutation • Most of life cycle inside cells • video

  21. Works Cited "Discovery Health "How Your Immune System Works"" Discovery Health "Health Guides" Web. 13 June 2011. <http://health.howstuffworks.com/human- body/systems/immune/immune-system11.htm>. Greenberg, Jon. BSCS Biology: a Molecular Approach. New York: Glencoe McGraw-Hill, 2001. Print. "HIV, AIDS and the Immune System." Information Technology. Web. 13 June 2011. <http://people.ku.edu/~jbrown/hiv.html>. Leukocyte functions. Digital image. Immune Cell Survival: Walking a Tightrope. Web. 13 June 2011. <http://lpi.oregonstate.edu/sp-su98/images/immune1.gif>. "Untitled Document." University of Virginia | Department of Biomedical Engineering (BME). Web. 13 June 2011. <http://bme.virginia.edu/ley/leukocytes.html>. YouTube - 3D Medical Animation: Antibody Immune Response‬‏. YouTube - Broadcast Yourself. Web. 13 June 2011. <http://www.youtube.com/watch?v=lrYlZJiuf18>. YouTube - HIV Destroys Helper T-cells | Biology | Anatomy | Immunology‬‏. YouTube - Broadcast Yourself. Web. 13 June 2011. <http://www.youtube.com/watch?v=U2h0ECyMWhE>. YouTube - Introduction to How the Immune System Works | Biology | Anatomy | Immunology‬‏. YouTube - Broadcast Yourself. Web. 13 June 2011. <http://www.youtube.com/watch?v=IWMJIMzsEMg>. YouTube - Macrophages, B-cells, Pathogens, Antibody Immune Response‬‏. YouTube - Broadcast Yourself. Web. 13 June 2011. <http://www.youtube.com/watch?v=iDYL4x1Q6uU>.

More Related