1. Unit 5 – Anatomy & Physiology Lymphatic & Immune System

2. Objectives By the end of the lesson you will be able to:- Describe the structures of the immune system Explain the function of the immune & lymphatic systems.

3. What you already know…….. How does the body protect itself from infection?

4. Immune System The immune system protects you from infections in three different ways: –It creates a barrier that prevents bacteria and viruses from entering your body. –If a bacteria or virus does get into the body, the immune system tries to detect and eliminate it before it can make itself at home and reproduce. –If the virus or bacteria is able to reproduce and start causing problems, your immune system is in charge of eliminating it.

5. Immune System The major components of the immune system are: –Skin –Thymus –Spleen –Lymph system –Bone marrow –White blood cells –Antibodies

6. Thymus Located in your chest, between your breast bone and your heart. It is responsible for producing T-cells. It is especially important in newborn babies – without it the immune system collapses and the baby will die. Less important in adults as other parts of the immune system can handle the load.

7. Spleen The spleen filters the blood to locate & identify foreign cells. A person missing their spleen gets sick much more often than someone with a spleen

8. Bone Marrow Bone marrow produces new red & white blood cells. Although some white blood cells mature elsewhere. The marrow produces all blood cells from stem cells. Stem cells change into actual, specific types of white blood cells.

10. White Blood Cells The white blood cells are probably the most important part of your immune system, they are a collection of different cells that work together to destroy bacteria and viruses.

11. Antibodies Antibodies are produced by white blood cells. They respond to specific antigens (viruses, bacteria etc). An antibody binds to an antigen & prevents movement through the cell walls.

12. Lymphatic System The lymphatic system is an extensive drainage network that helps keep bodily fluid levels in balance, defends the body against infections, and assists in tissue repairs.

13. 3 components 1. Vessels –A network of lymphatic vessels that begins in the peripheral tissues and connects to the venous system. 2. Fluid –Called Lymph (clear and watery), flows through the lymphatic vessels. –Lymph Fluid contains: Fluid from the intestines (chyme), which contains proteins and fats. Red blood cells White blood cells, especially lymphocytes, the cells that attack bacteria in the blood 3. Lymphoid organs –Lymphoid organs are connected to the lymphatic vessels and contain large numbers of lymphocytes. (bone marrow, spleen) Lymphatic System

14. The production, maintenance and distribution of lymphocytes. –to defend the body against disease by producing lymphocytes –The lymphocytes, protect the body against antigens (viruses, bacteria, etc.) that invade the body. –Lymphocytes are produced and stored within lymphoid organs, such as the spleen, thymus and bone marrow.

15. The distribution of hormones, nutrients and waste products from their tissues to the general circulation. –to absorb lipids from the intestine and transport them to the blood. –Substances that are unable to enter the blood stream directly can do so via the lymphatic vessels.

16. The return of fluid and solutes from the peripheral tissues of the blood. –to collect and return interstitial fluid, including plasma protein to the blood, and thus help maintain fluid balance. –The return of fluids through the lymphatic system maintains normal blood volume.

17. To clarify………. What is the difference between the immune system & the lymphatic system?

18. Further Reading http://health.howstuffworks.com/huma n-body/systems/immune/immune- system.htmhttp://health.howstuffworks.com/huma n-body/systems/immune/immune- system.htm