IMMUNITY



IMMUNITY – body’s reaction to any foreign body that might enter our tissues
2 types:
  • NON SPECIFIC/ CELLULAR / Innate immunity present in our body since we were born
  • SPECIFIC
Mediators (non specific)

1. MECHANICAL BARRIERS
  • Skin (keratinized)
  • Body secretions ( sweat, oil)
  • Cilia (transports)
  • Mucus (traps organism entering the Respiratory tract)
2. CHEMICAL BARRIERS
  • Enzymes (lysozymes)
  • Acids ( kills bacteria by denaturation)
    Fatty acids – skin
    Gastric acids – stomach
  • Complement system – becomes activated in cascade fashion 1,2,3…..
    Activated Complements System – presents antigen to the bacteria; once activated, has to be removed from the body
3. INFLAMMATORY RESPONSE
Presents the 5 Cardinal signs which is chemically mediated that can come from:
  • Damaged tissues
  • Inflammatory cells
  • Even from the bacteria itself

5 Cardinal signs & symptoms of inflammation:
1. redness (rubor)
2. swelling (tumor)
3. pain (dolor)
4. heat (calor)
5. loss of function (functiolaesa)
FXN:
  • forms a barrier to confine infection
  • tries to eliminate infectious agent
  • initiates repair of damaged tissues
4. CELLS – WBC’s

a) GRANULOCYTES – granulocytic leukocytes; WBC’s with granules inside the cytoplasm
1. Neutrophiles – plenty; 1st line of defense; 1st to respond during an infection
HALLMARK OF ACUTE INFECTION (10days)
Once they leave, they cannot go back (through “DIAPEDESIS”)
CBC - increased Neutrophiles = acute infection
Disease is current; can be bacterial
HOW DO NEUTROPHILES KILL BACTERIA?
  • Phagocytic – active engulfing
  • Degranulation – release granules in the cytoplasm which contains cytotoxins that kill the bacteria
2. Eosinophiles – mediate for Allergies; Hypersensitivity reaction; Anaphylactic reaction;
Contains vasoactive dilators:
  • Serotonin
  • Histamine
  • Bradykinin
Limited phagocytic activities
“Picky eaters” eat only * complement system, * Ag aggregated with Ab
3. Basophiles – HEPARIN – anti coagulant; lesser blood clots

b) AGRANULOCYTES

1. Monocytes – found in the blood which rids bacteria, virus, and other debris
“scavengers” (10 days in circulation)
ACTIVE phagocytes
DIAPEDESIS – mode of escape w/o damage
MACROPHAGES – once they are out, monocytes take this form; derivative
Neutrophiles, Monocytes, Macrophages = 3 active phagocytic cells
2. Lymphocytes – non phagocytic cells
HALLMARK OF CHRONIC INFECTION
a) T –CELLS/ T-LYMPHOCYTES = (Cellular Immunity)
T- cells mature in the Thymus glands(Lymphoid organs)
Once there is an infection, they become ACTIVE EFFECTOR CELLS
  • Natural killer cells – non phagocytic cells which kills by secreting LYMPHOKINES
    kills ON CONTACT; has intimate contact with bacteria (sila ang Police na pumapatay sa kahit sinong magnanakaw - virus,bacteria)
  • Helper cells – calls for other WBC’s which circulate around the body by secreting “OPSONINS” (chemically attract WBC). WBC aids in the attack; (nagtatawag para may katulong ang Police sa laban)
  • Suppressor cells – the absence of these mediators will cause destruction of normal tissues
    (taga awat kung bugbog na ang kalaban, kung walang aawat sila-sila din ang magpapatayan kahit kakampi nila- "Autoimmune disease")
b) B CELLS/ B LYMPHOCYTES - mediator of specific immunity
  • must 1st recognize specific Ag (nag draw-drawing ng cartographic sketch ng magnanakaw the 1st time na pumasok sya sa bahay)
  • acquires Ab’s once exposed to microorganism (ipapakita niya yung drawing niya sa police para next time na papasok ang magnanakaw kilala na ng police at bubugbugin na niya ang magnanakaw)

  • improves with exposure (mas madalas niya makita at mas madalas sya manakawan, mas lalo na niya nakikilala ang magnanakaw para lalong maituro at mahuli ng police )
  • Humoral immunity

  • ACTIVE EFFECTOR B CELLS:
    • MEMORY CELLS – (Ang "WITNESS" na nag draw-drawing ng cartographic sketch ng magnanakaw the 1st time na pumasok sya sa bahay)
    • PLASMA CELLS – makes Ab’s specific to description of the memory cells; (bumubuo ng "TASK FORCE POLICE" para lumaban sa muling pagbalik, dun lang sa magnanakaw na nai-drawing ng witness - "Antigen-Antibody Response")


      IMMUNIZATION – is the process by which we reinforce our immune system by introducing antigens that stimulate antibody responses
    • ACTIVE – our own body participates in the production of Ab’s
      slow acting so it is introduced during our childhood; last longer than passive
      VACCINES – made up of dead, inactivated organisms; parts of Ag’s; or attenuated (weakened virus or bacteria)
    • PASSIVE – giving antibodies (Ab’s) especially during epidemic
      Gives immediate protection but temporary (3-6months)
      Ex. Equine vaccine from horses
      A) NATURAL – from mother to baby
      B) PASSIVE – Ab’s from other sources

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