The Immune system

1. The Immune system What it is and its role in the body

2. Immune System • Purpose is to keep infectious microorganisms out of the body and destroy those that enter. • Made up of a complex system of organs and cells

3. Organs involved are called lymphoid organs

4. White Blood Cells • Also called Leukocytes • Phagocytes • Attack invading pathogens • Macrophages • Type of Phagocyte • Reacts by engulfing pathogen and making antigens identifiable

5. Immune Response • Antigens • Substances that can trigger an immune response • Antibody • A protein that acts against a specific antigen

6. Lymphocytes • Type of infection-fighting white blood cell • Patrol for pathogens • Originate in bone marrow • Two types of lymphocytes • B cells • Finish maturing in bone marrow • T cells • Finish maturing in thymus • Once matured, some stay in lymphoid organs while others go out on patrol

7. T cells • 3 types • Helper • Facilitates production of B cells and Killer T cells • Killer • Attack and destroy infected body cells, not the pathogen • Suppressor • “Commanding Officers” • Coordinate actions of other T cells

8. B cells • Produce antibodies • Each cell is programmed to make one type of antibody that is specific to a type of pathogen • Antibodies will: • Attach to antigens to mark them for destruction • Destroy invading pathogens • Block viruses from entering body cells

9. Immune Response • Pathogens Invade • Macrophages engulf pathogen • Macrophages digest pathogen; T cells recognize antigens of pathogen as invaders • T cells bind to antigens • B cells bind to antigens and helper T cells • B cells divide and produce plasma cells • Plasma cells release antibodies into bloodstream • Antibodies bind to antigens to help other cells identify and destroy pathogens

10. Common Pathogens that Cause Infectious Diseases • Viruses • Bacteria • Fungi • Protozoa • Rickettsias

11. Virus • Piece of genetic material surrounded by a protein coat • Reproduce by invading cells of living organisms • Multiply then begin taking over other cells • Most common are the cold and influenza • Antibiotics DO NOT work against viruses

12. Bacteria • Single-celled microorganisms • Most are harmless and some are helpful • Disease-causing produce toxins • Substances that kill cells or interfere with their functions • Antibiotics kill bacteria

13. Spreading Disease • Direct Contact • Touching, kissing, etc. • Indirect Contact • Sharing contaminated objects, vectors such as insects • Airborne • Sneezing or coughing pathogens out of your body can enter another’s, fungal spores

14. Vaccinations • Vaccinations are weak or dead pathogens intentionally put into the body • Immune response takes over and develops the antibodies to defend against the actual disease if it ever enters the body • Why do we need a flu shot every year? • Why isn’t there one vaccine for the common cold?

15. Allergic Reactions • Allergy • Disorder of the immune system • Allergic Reactions are the result of the immune system dramatically responding to what it interprets as a threat (dust, pollen, pet dander, etc.) • Allergens • Substances that cause allergic reactions • Reactions can range from minor (watery eyes, itchiness, slight wheezing, runny nose) to major (hives, swelling of tongue and throat, difficulty breathing, dizziness, headache, stomach issues, shock, or loss of consciousness)

16. Anaphylactic Shock • Life threatening reaction to allergens • People who suffer major reactions can go into anaphylactic shock. • Sudden drop in blood pressure occurs • Usually caused by reactions to allergens in food, insect bites or stings, drug, or chemical • People who are aware of life-threatening allergies may have an EpiPen ready to use • EpiPen – single dose of epinephrine to be administered to the outer thigh only. • Increases heart rate and strength of heart beat • Dr. prescribed only!! • When an EpiPen needs to be used medical attention is needed immediately after administration

17. HIV and AIDS • HIV • Human Immunodeficiency Virus • Leads to AIDS (Acquired Immune Deficiency Syndrome) • Destroys specific T cells (CD4+ T cells) crucial to helping the body fight infections • HIV can exist for years before leading to AIDS • HIV levels increase while the T cells decrease • Leaves body more prone to infections and diseases

18. How HIV Works • HIV Virus in blood • Attaches to T cell • Empties contents into cell • Viral DNA is created and inserts into cell’s DNA • Infected cell divides with new DNA code • Cell division creates raw protein material • Raw infected material is packaged into an immature virus cell • Leaves infected cell through “budding” • New immature cell matures and then attacks another healthy cell • New infected cells are slightly different (mutations) than where they came from

19. HIV Symptoms • Very few, if any symptoms show at first • Roughly 2 to 3 months after contraction, flu-like symptoms will show including fatigue and swollen lymph nodes in neck and groin • Symptoms may go away

20. HIV Later Stage Symptoms • Later stage symptoms • Rapid Weight Loss • Recurring night sweats and fever • Extreme fatigue • Prolonged lymph node swelling • Diarrhea lasting more than a week • Sores at the mouth, anus, and genitals • Red, brown, pink, or purple splotches under the skin or inside mouth, nose, or eyelids

21. HIV Treatment • Antiretroviral Therapy (ART) • Drugs do not kill the virus but slow its ability to spread and infect healthy cells • About 30 different drugs available • Block different stages of the virus’ reproduction and infection process

22. AIDS • Acquired Immunodeficiency Syndrome • Is not HIV but occurs during late stages of HIV • Immune system becomes deficient • Diagnosed when patient contracts one or more specific Opportunistic Infections (OI), certain cancers, or has a very low CD4+ T cell count

23. Other Sexually Transmitted Diseases • Half of all new sexually transmitted diseases occur among people aged 15-24 • Common STDs are: • Bacterial Vaginosis (BV) • Chlamydia • Gonorrhea • Viral Hepatitis • Genital Herpes • Human Papillomavirus (HPV)

24. Sexually Transmitted Diseases • Pelvic Inflammatory Disease (PID) • Syphilis • Trichomoniasis • Pubic Lice • Scabies

25. Chlamydia • Most commonly reported STD in the United States • Affects both men and women • Sexually active women age 25 and younger need testing every year • Easy to cure yet an untreated infection can impact a woman’s ability to have children later in life by causing permanent damage to reproductive organs • “Silent Infection”

26. Chlamydia • Most people show no symptoms when contracted • Women • Starts in the cervix or urethra then spreads to uterus and fallopian tubes • Leads to Pelvic Inflammatory Disease (PID) • Could cause unusual discharge from vagina or burning sensation when urinating • Men • Could have discharge from penis or burning sensation • Pain and swelling in one or both testicles (epididymitis) could occur

27. Treatment for Chlamydia • Antibiotics • During treatment, abstain from sexual activity (7 days) • Repeat infection can occur

28. Gonorrhea • CDC estimates that about 820,000 people contract gonorrhea annually • Estimated that 570,000 are 15-24 years old • Affects both men and women

29. Gonorrhea • Men • Burning sensation when urinating • White, yellow, or green discharge from penis • Epididymitis can occur • Symptoms appear between 1-14 days after infection • Women • Usually show no symptoms • Can be mistaken for bladder or vaginal infection • Discharge, burning when urinating, or bleeding between periods can occur • Can lead to PID

30. Treatment for Gonorrhea • Left untreated, can be life-threatening by spreading to blood and joints • Different antibiotics can be prescribed • Drug-resistant gonorrhea has become more prevalent

31. Syphilis • CDC estimates that approx. 55,400 people are affected • First symptoms can appear within 21 days, but can appear as late as 90 days after infection • Three stages of symptoms

32. Primary Stage Syphilis • Single, painless sores appear where disease entered body • Sores are firm and round • Lasts 3 to 6 weeks and heals even if untreated

33. Secondary Stage Syphilis • Skin rashes, sores on mouth and genitals • Rashes are not itchy and can affect different parts of body • Gray or white lesions occur in mouth • Fever, swollen lymph glands, patchy hair loss, headaches, weight loss, muscle aches, and fatigue can occur

34. Late Stage Syphilis • Occurs when primary and secondary symptoms disappear • Can appear 10-30 years after contraction • Affects muscle coordination and can cause paralysis, dementia, numbness, and gradual blindness • Damages multiple internal organs which can lead to death • Antibiotics treats syphilis but does not reverse damage