Immune System: Lymphatic Organs & Diseases

1. Immune System Part 1: Lymphatic Organs & Disease Chapter 13 / 40-1

2. Overview • I. Immune System Functions • II. Lymphatic Organs & Tissues • III. Immune Disorders • IV. Infectious Disease • V. Immune Defenses • VI. Immunity

3. I. Immune System • Consists of a network of lymphatic organs, tissues, and cells • Plays an important role in keeping us healthy • When homeostasis is NOT in balance, the body has disease

4. Function • Defends body against disease using white blood cells to maintain homeostasis • White blood cells are produced by the lymphatic organs to fight pathogens invading the body • Pathogens are things that infect you and make you sick

5. II. Lymphatic Organs • 1. Red Marrow • 2. Thymus • 3. Spleen • 4. Lymph nodes & vessels • 5. Tonsils & Adenoids • 6. Appendix & Peyer’s patches

6. 1. Red Bone Marrow • Function: site of stem cell production and creation of white blood cells. • In adults, red marrow is found in long and flat bones. • In children it is found in most bones

7. 5 Types of White Blood Cells • Neutrophil, eosinophil, basophil, monocyte, lymphocyte (B lymphocyte & T lymphocyte)

8. 2. Thymus • Located below the sternum • Larger in children, shrinks with age • Critical to immunity • Function: allows the body to reject foreign tissues or invading pathogens • Immature T-lymphocytes (from red marrow) move to the thymus where they mature

10. 3. Spleen • Located on the left side of the abdomen • Function: Filters blood cells and destroys worn out blood cells, engulfs debris • Can live with out the spleen but more susceptible to infections

11. 4. Lymph Nodes & Vessels • Function: Lymph nodes filter lymph • Lymph– excess tissue fluid carried by lymphatic vessels • Mostly made of water and dissolved substances (electrolytes, oxygen) • Lymph may contain white blood cells, bacteria, viruses, cancer cells and cell debris

12. 4. Lymph Nodes & Vessels • Nodes can become swollen when infected • Function: Lymph vessels transport lymph from tissues and nodes back to the heart

13. 5. Tonsils & Adenoids • Small masses of lymphatic tissue around the pharynx • Function: Trap and remove pathogens and other foreign materials that enter the mouth or nose • Adenoids, like the thymus, shrink with age

14. 6. Appendix & Peyer’s Patches • Both are located in intestinal wall • Function: Encounter pathogens that enter the body through the intestinal tract.

15. III. Immune Disorders • A. Allergies • Tricks immune system to have response • Response is harmful rather than protective because it attacks our own cells

16. Symptoms of allergic reaction • Hives, itching, swelling • Tightness of chest, difficulty breathing • Swelling of tongue • Dizziness, drop in BP • Anaphylactic shock • Unconsciousness or cardiac arrest

18. B. Edema • Localized swelling due to the accumulation of lymph • Can lead to tissue damage and eventual death if untreated

19. C. Autoimmune Diseases • The immune system does not distinguish between self and non-self • The body produces white blood cells that attack its own tissues

20. Examples of autoimmune diseases • Multiple sclerosis – white matter of brain and spinal cord are destroyed • Juvenile diabetes – destroys pancreatic beta cells that produce insulin • Rheumatoid arthritis – destroys joints

21. III. Infectious Disease • Disrupts normal body function (homeostasis) • Caused by a pathogen. • Pathogen: anything that invades your body & causes a disease • Ex: bacteria, protozoan, fungi, viruses, parasites, worms • It can be contagious (passed from person to person)

22. A. Disease Transmission • People may carry a disease without even knowing it. • Can be spread during the incubation period (before symptoms occur) • Transmission by: • 1. Direct contact • Kissing • 2. Indirect contact-through the air • coughing & sneezing • 3. Contact with object • sharing drinks, door knobs, desks

23. 4. Infected animals • Vector transmits disease • Ex: mosquito • 5. Contaminated food or water • food poisoning

24. B. Agents of Disease • 1. Protists • feed on nutrients in host’s blood • ex: malaria, dysentery • 2. Worms • parasitic flatworms & round worms • ex: tapeworms & hook worms • 3. Fungi • attack moist areas, like the skin, scalp, mouth & throat • ex: ringworms & athlete’s foot • 4. Bacteria • 5. Viruses See Next Sections

25. 4. Bacteria • Bacteria (prokaryotes) have a cell wall, cell membrane, genetic material, and ribosomes for protein production • Bacteria do not have a nucleus or organelles • Bacteria are living cells

27. They cause disease by: • Releasing toxins that are poisonous to people • Break down tissues of infected organism for food • Infectious forms of bacteria- • Cholera, Bubonic Plague, tuberculosis, gonorrhea, anthrax, streptococcus, staphylococcus • Treatment: ANTIBIOTICS

28. Antibiotic Resistance • Currently, many bacteria are becoming resistant to antibiotics • This is because of antibiotics being over prescribed • (often for viral infections, which they have no effect on) • MRSA – Methicillin-resistant Staphylococcus areus • Bacterial strain resistant to antibiotics

30. 5. Virus • Viruses are non-living, non-cellular structures thousands of times smaller than a cell • Structure: DNA surrounded by a protein coat • Virus cannot reproduce itself • Virus relies on a HOST cell to replicate • A virus usually tricks the host to pull it into cell • Virus genetic material takes over the host cell causing the cell to make new viruses

32. Common types of human viruses: • Influenza, chicken pox, polio, HIV, common cold, and Herpes (cold sores) • Uncommon types of human viruses: • Ebola, West Nile Virus, Dengue Fever, Smallpox HIV Virus

33. Prevention • Vaccines PREVENT viral infection • Person is injected with a weakened virus. • The immune system can later recognize the normal virus and fight it off • Ex: measles, mumps, rubella (MMR), smallpox, polio, flu strains (swine flu)

34. Treatment • Viral infections are fought by the immune system or with anti-viral drugs. • Some viruses are too strong and too fast for the immune system to fight. • These viruses lead to: • Epidemics(over large areas) • Pandemics (over whole countries) • To treat mass outbreaks: contain the area and quarantine the infected.

35. Common Viruses Human Papilloma Virus (HPV) Influenza (Flu Virus) • Kills 30,000 Americans every year

36. Deadly Viruses SARS (Severe acute respiratory syndrome) • China 2002-3 • 5328 cases, 349 deaths Ebola virus • Africa • ~90% mortality rate

38. The Immune System Part 2: Immune Defenses Human Body Systems Chapter 13/ 40-2

39. I. Immune System Overview • Immune System: body’s defense system against disease • 2 Defense Systems for foreign materials • Nonspecific Defense System • Specific Defense System • Includes White Blood Cells (WBCs) to fight infection through inactivating foreign materials or cells • Soldiers of your defense system

40. A. Pathogens & Antigens • Pathogens (things that infect you) contain antigens • Antigens are like chemical markers (name tag) that tell what the pathogen is Haha! I am the pathogen. I have invaded you! HI, MY NAME IS Swine Flu Virus Antigen

41. B. WBCs & Antibodies • WBCs can recognize the antigens because they have antibodies. • Antibodies are proteins that recognize and bind to the antigen because they fit together • Antibodies mark the pathogen for destruction Nooo! Y Y Y Y Antibody

42. C. Types of WBCs • Phagocytes - “eat” & destroy pathogens • Macrophages, Neutrophils, Monocytes • Eosinophils – deal with parasitic infections • Basophils – involved in allergic reactions • Lymphocytes – deal with specific invaders • B-lymphocytes- make antibodies • T-lymphocytes- cells- recognize & kill pathogen Nooo! Y Y Y Y

45. II. Immune Divisions • A. Nonspecific Defenses • B. Specific Defenses • C. Acquired Immunity

46. A. Nonspecific Defenses • Body protects itself the SAME way regardless of what is invading it • Protects against variety of invaders • Fast-acting Response • Lines of Defense • 1. Skin, Sweat, Mucus & Tears • 2. Immune Response • Fever, Macrophages, Inflammation

47. 1. First Line of Defense • Skin, sweat, mucus, and tears • Skin is a physical barrier to keep pathogens out of the body • Cuts or breaks in the skin allow pathogens to enter • Sweat, mucus, & tears contain lysosomes and other chemicals that kill bacteria.

48. 2. Second Line of Defense • Immune response – pathogens are recognized by antigens • Fever – body raises temperature to slow down growth & replication of pathogen • Macrophages – WBCs designed to eat pathogens • Inflammation – infected area swells with lymph and blood bringing WBCs and macrophages to fight pathogen