THE IMMUNE SYSTEM

1. THE IMMUNE SYSTEM

2. THE IMMUNE SYSTEM • NONSPECIFIC DEFENSES AGAINST INFECTION INCLUDE THE • SKIN • MUCOUS MEMBRANES • PHAGOCYTIC CELLS • ANTIMICROBIAL PROTEINS

3. THE IMMUNE SYSTEM • NONSPECIFIC DEFENSE MEANS THAT THEY DON’T DISTINGUISH BETWEEN MICROBES • THE SKIN IS THE FIRST LINE OF DEFENSE • THE RESPIRATORY AND DIGESTIVE SYSTEMS ARE OPEN TO THE ENVIRONMENT; LINED WITH MUCUS TO PREVENT BACTERIAS (MICROBES) FROM ENTERING

4. THE IMMUNE SYSTEM • NONSPECIFIC DEFENSE MEANS THAT THEY DON’T DISTINGUISH BETWEEN MICROBES • IF MICROBES DO ENTER THE BODY CELLS OR TISSUES THEN • NEUTROPHILS AND MONOCYTES ATTACK FOREIGN BODY • PHAGOCYTIC CELLS

5. THE IMMUNE SYSTEM • NONSPECIFIC DEFENSE MEANS THAT THEY DON’T DISTINGUISH BETWEEN MICROBES • IF MICROBES DO ENTER THE BODY CELLS OR TISSUES THEN • NEUTROPHILS AND MONOCYTES ATTACK FOREIGN BODY • MACROPHAGES • LARGE MONOCYTES THAT WANDER ACTIVELY THROUGH INTERSTITIAL FLUID

6. THE IMMUNE SYSTEM • NONSPECIFIC DEFENSE MEANS THAT THEY DON’T DISTINGUISH BETWEEN MICROBES • IF MICROBES DO ENTER THE BODY CELLS OR TISSUES THEN • NEUTROPHILS AND MONOCYTES ATTACK FOREIGN BODY • NATURAL KILLER CELLS ATTACK CANCER CELLS AND INFECTED BODY CELLS • INTERFERONS  PROTEINS PRODUCED BY VIRUS-INFECTED CELLS THAT HELP OTHER CELLS RESIST VIRUSES (VIRUS INFECTION ACTIVATES INTERFERON GENE) • COMPLEMENT PROTEINS  COAT SURFACES OF MICROBES TO EASE PHAGOCYTOSIS, CUT HOLES IN MICROBE MEMBRANE, OR AMPLIFY INFLAMMATORY RESPONSE

7. THE IMMUNE SYSTEM • THE INFLAMMATORY RESPONSE MOBILIZES NONSPECIFIC DEFENSE FORCES

8. THE IMMUNE SYSTEM • INFLAMMTORY RESPONSE • MAJOR COMPONENT OF OUR NONSPECIFIC DEFENSE SYSTEM • DAMANGED CELLS RELEASE CHEMICAL ALARM SIGNALS LIKE HISTAMINE • DILATES THE BLOOD VESSELS MAKING THEM LEAKIER • CHEMICALS SPARK THE MOBILIZATION OF VARIOUS DEFENSES • THE WHITE BLOOD CELLS GATHERED IN THE AREA ENGULF THE BACTERIA AND THE REMAINS OF ANY DAMAGED OR DEAD CELLS

9. THE IMMUNE SYSTEM • INFLAMMATORY RESPONSE • HELPS PREVENT SPREAD OF INFECTION BY RELEASING CLOTTING FACTORS • INFLAMMATORY RESPONSE MAY BE LOCALIZED OR WIDESPREAD (EX. FEVER) • WIDESPREAD INFLAMMATION CAN BE DANGEROUS • SEPTIC SHOCK  BACTERIAL INFECTION THAT BRINGS ABOUT OVERWHELMING INFLAMMATORY RESPONSE

10. THE IMMUNE SYSTEM • THE LYMPHATIC SYSTEM BECOMES A CRUCIAL BATTLEGROUND DURING INFECTION

11. THE IMMUNE SYSTEM • LYMPHATIC SYSTEM • CONSISTS OF A BRANCHING NETWORK OF VESSELS, NUMEROUS LYMPH NODS (SAC-LIKE ORGANS PACKED WITH THE WHITE BLOOD CELLS CALLED LYMPHOCYTES), THE TONSILS AND ADENOIDS, THE APPENDIX AND THE SPLEEN

12. THE IMMUNE SYSTEM • LYMPHATIC SYSTEM • ALSO INCLUDES THE BONE MARROW AND THYMUS (SITES WHERE WHITE BLOOD CELLS DEVELOP) • 2 MAIN FUNCTIONS • RETURN TISSUE FLUID TO THE CIRCULATORY SYSTEM • FIGHT INFECTION • LYMPH • FLUID CARRIED IN THE LYMPATHIC VESSELS; SIMILAR TO INTERSTITIAL FLUID BUT LESS OXYGEN AND NUTRIENTS • **SWOLLEN GLANDS ARE THE RESULT OF LYMPH NODES MAKING EXTRA LYMPHOCYTES TO FIGHT INFECTION

13. THE IMMUNE SYSTEM • THE IMMUNE RESPONSE COUNTERS SPECIFIC INVADERS • IMMUNE SYSTEM  RECOGNIZES AND DEFENDS AGAINST INVADING MICROBES AND AGAINST CANCER CELLS • ANTIGEN  A MOLECULE THAT ELICITS AN IMMUNE REPONSE • ANTIBODY  A PROTEIN FOUND IN BLOOD PLASMA THAT ATTACHES TO ONE PARTICULAR KIND OF ANTIGEN AND HELPS COUNTER ITS EFFECTS

14. THE IMMUNE SYSTEM • THE IMMUNE RESPONSE COUNTERS SPECIFIC INVADERS • IMMUNE SYSTEM HAS A REMARKABLE “MEMORY”; ONCE IT ENCOUNTERS AN ANTIGEN IT REMEMBERS IT AND CAN COMBAT IT VERY QUICKLY • IMMUNITY  RESISTANCE TO SPECIFIC INVADERS

15. THE IMMUNE SYSTEM • IMMUNITY  RESISTANCE TO SPECIFIC INVADERS • CAN BE ACQUIRED NATURALLY OR BY VACCINATION • VACCINE  HARMLESS VARIANT OF A DISEASE-CAUSING MICROBE • STIMULATESTHE IMMUNESYSTEM TOMOUNTDEFENSESAGAINST THEVARIANT

16. THE IMMUNE SYSTEM • IMMUNITY • 2 FORMS • ACTIVE IMMUNITY • BODY IS STIMULATED TO PRODUCE ITS OWN ANTIBODIES • PASSIVE IMMUNITY • BODY IS GIVEN ANTIBODIES (NOT PERMANENT!!) • EXAMPLES INCLUDE:FETUS GETS FROM MOTHER; A DIRECT SHOT OF ANTIBODIES

17. THE IMMUNE SYSTEM • LYMPHOCYTES MOUNT A DUAL DEFENSE • LYMPHOCYTES • WHITE BLOOD CELLS THAT SPEND MOST OF THEIR TIME IN THE TISSUES AND ORGANS OF THE LYMPATIC SYSTEM

18. THE IMMUNE SYSTEM • B CELLS • ARISE FROM IMMATURE LYMPHOCYTES THAT DEVELOP IN THE BONE MARROW • GIVE RISTER TO HUMORAL IMMUNITY • IMMUNITY OCCURING IN THE BODY FLUIDS

19. THE IMMUNE SYSTEM • T CELLS • ARISE FROM IMMATURE LYMPHOCYTES THAT DEVELOP IN THE THYMUS • GIVE RISE TO CELL-MEDIATED IMMUNITY • ATTACKS INFECTED CELLS • ANTIGEN RECEPTORS • MOLECULES CAPABLE OF BINDING TO A SPECIFIC TYPE OF ANTIGEN

20. THE IMMUNE SYSTEM • CLONAL SELECTION MUSTERS DEFENSIVE FORCES AGAINST SPECIFIC ANTIGENS • CLONAL SELECTION • ATTACHMENT OF AN ANTIGEN TO A SPECIFIC LYMPHOCYTE CAUSES MULTIPLICATION OF THAT LYMPHOCYTES VIA MITOSIS

21. THE IMMUNE SYSTEM • THE INITIAL IMMUNE RESPONSE RESULTS IN A TYPE OF “MEMORY” • IT TAKES TWO EXPOSURES TO AN ANTIGEN TO MOUNT THE STRONGEST IMMUNE RESPONSE

22. THE IMMUNE SYSTEM • THE INITIAL IMMUNE RESPONSE RESULTS IN A TYPE OF “MEMORY” • PRIMARY IMMUNE RESPONSE • OCCURS WHEN LYMPHOCYTES ARE FIRST EXPOSED TO AN ANTIGEN AND FORM A CLONE OF EFFECTOR CELLS • SECONDARY IMMUNE RESPONSE • AFTER PRIMARY; SECOND EXPOSURE ELICITS FASTER, STRONGER RESPONSE • MEMORY CELLS • MADE AT SAME TIME AS EFFECTOR CELLS; DIFFER IN STRUCTURE AND FUNCTION; MAY LAST FOR DECADES

23. THE IMMUNE SYSTEM • OVERVIEW: B CELLSARE THE MAIN WARRIORS OF HUMORAL IMMUNITY • PLASMA CELLS • ANOTHER NAME FOR EFFECTOR B CELLS, THE ONES PRODUCING ANTIBODIES • ANTIBODIES ARE THE WEAPONS OF HUMORAL IMMUNITY • ANTIBODY HAS 2 RELATED FUNCTIONS • RECOGNIZE AND BIND TO CERTAIN ANTIGENS • ASSIST IN NEUTRALIZING THE ANTIGEN • ANTIGEN-BINDING SITE • REGION OF THE MOLECULE RESPONSIBLE FOR THE ANTIBODY’S RECOGNITION-AND-BINDING FUNCTION

24. THE IMMUNE SYSTEM • ANTIBODIES MARK ANTIGENS FOR ELIMINATION • ANTIBODIES BIND TO FORM ANTIBODY-ANTIGEN COMPLEX WHICH ALLOWS FOR ANTIGEN DESTRUCTION

25. THE IMMUNE SYSTEM • MONOCLONAL ANTIBODIES ARE POWERFUL TOOLS IN THE LAB AND CLINIC • MONOCLONAL ANTIBODIES • ALL THE CELLS PRODUCING THE ANTIBODIES ARE DESCENDANTS OF A SINGLE CELL AND THEREFORE ARE IDENTICAL • GREAT PROMISE IN MEDICINE AND RESEARCH

26. THE IMMUNE SYSTEM • T CELLS MOUNT THE CELL-MEDIATED DEFENSE AND AID HUMORAL IMMUNITY • 2 MAIN KINDS OF T CELLS

27. THE IMMUNE SYSTEM • T CELLS MOUNT THE CELL-MEDIATED DEFENSE AND AID HUMORAL IMMUNITY • 2 MAIN KINDS OF T CELLS • CYTOTOXIC T CELLS • ATTACK BODY CELLS THAT ARE INFECTED WITH PATHOGENS • HELPER T CELLS • HELP ACTIVATE CYTOTOXICT CELLS AND MACROPHAGES,EVEN HELP STIMULATE B CELLSTO PRODUCE ANTIBODIES

28. THE IMMUNE SYSTEM • T CELLS MOUNT THE CELL-MEDIATED DEFENSE AND AID HUMORAL IMMUNITY • CYTOTOXIC T CELLS • ATTACK BODY CELLS THAT ARE INFECTED WITH PATHOGENS • CTYOTOXIC T CELLS BIND TO ANTIGEN • WHEN BOUND IT CAUSES THE PRODUCTION OF PERFORIN • PROTEIN THAT CUTS HOLES IN MEMBRANE • ALLOWS OTHER PROTEINS TO ENTER AND CAUSE DEATH OF ANTIGEN

29. THE IMMUNE SYSTEM • T CELLS MOUNT THE CELL-MEDIATED DEFENSE AND AID HUMORAL IMMUNITY • CYTOTOXIC T CELLS • MAY HELP PREVENT CANCER • MONITOR CELLS AND DESTROY CANCEROUS ONES • IT’S A MYSTERYWHY THEYSTOP WORKING

30. THE IMMUNE SYSTEM • T CELLS MOUNT THE CELL-MEDIATED DEFENSE AND AID HUMORAL IMMUNITY • HELPER T CELLS • HELP ACTIVATE CYTOTOXICT CELLS AND MACROPHAGES,EVEN HELP STIMULATE B CELLSTO PRODUCE ANTIBODIES

31. THE IMMUNE SYSTEM • THE IMMUNE SYSTEM DEPENDS ON OUR MOLECULAR FINGERPRINTS • MAJOR HISTOCOMPATIBILITY COMPLEX (MHCs) • GROUP OF SELF-PROTEIN GENES • PROTEINS FOUND ON OWN CELLS; MARK THEM AS “OFF-LIMITS” TO IMMUNE SYSTEM

32. THE IMMUNE SYSTEM • MALFUNCTION OR FAILURE OF THE IMMUNE SYSTEM CAUSES DISEASE • AUTOIMMUNE DISEASES • RESULTS WHEN THE IMMUNE SYSTEM GOES AWRY AND TURNS AGAINST THE BODY’S OWN MOLECULES (EXAMPLE = LUPUS)

33. THE IMMUNE SYSTEM • MALFUNCTION OR FAILURE OF THE IMMUNE SYSTEM CAUSES DISEASE • IMMUNODEFICIENCY DISEASES • LACK ONE OR MORE COMPONENTS OF THE IMMUNE SYSTEM, AND ARE SUSCEPTIBLE TO INFECTIONS THAT ORDINARILY WOULD NOT CAUSE A PROBLEM (EXAMPLE = HODGKIN’S; AIDS)

34. THE IMMUNE SYSTEM • ALLERGIES ARE OVERREACTIONS TO CERTAIN ENVIRONMENTAL ANTIGENS • ALLERGIES • ABNORMAL SENSITIVITIES TO ANTIGENS IN OUR SURROUNDINGS

35. THE IMMUNE SYSTEM • ALLERGIES ARE OVERREACTIONS TO CERTAIN ENVIRONMENTAL ANTIGENS • ALLERGENS • ANTIGENS THAT CAUSE ALLERGIES • MAST CELLS • NORMAL BODY CELLS THAT PRODUCE HISTAMINE AND OTHER CHEMICALS THAT TRIGGER THE INFLAMMATORY RESPONSE • ANTIHISTAMINES • DRUGS THAT INTERFERE WITH HISTAMINE’S ACTION AND GIVE TEMPORARY RELIEF FROM AN ALLERGY • ANAPHYLACTIC SHOCK • VERY SEVERE (POSSIBLY FATAL) ALLERGIC REACTION • CAN BE COUNTERED WITH AN INJECTION OF EPINEPHRINE (ADRENALINE)

36. THE IMMUNE SYSTEM • AIDS LEAVE THE BODY DEFENSELESS • HIV DESTROYS THE HELPER T CELLS; TURNING OFF HUMORAL AND CELL MEDIATED IMMUNE RESPONSES • LEAVES THE BODY DEFENSELESS AND OPEN TO OPPORTUNISTIC INFECTIONS • AIDS DOESN’T KILL, OPPORTUNISTIC INFECTIONS DUE

37. THE IMMUNE SYSTEM • SOME THINGS THAT ARE BAD FOR US; OR THAT ARE NOT SUPPOSED TO BE INSIDE OF US, ARE THE RESULT OF CHEMICAL (METABOLIC) REACTIONS IN OUR CELLS…OUR IMMUNE SYSTEM CAN’T BE RESPONSIBLE FOR THESE • WE NEED THE EXCRETORY SYSTEM!!!