immunity

• Immunity

  -        resistance to disease
• Immune system

  -        provides defense against all the microorganisms and toxic cells
• The Immune System

  -        a functional system
• 1.      Nonspecific Immunity

  -        an innate reaction

  -        response against all kinds of pathogens
• a.     physical and chemical barriers

  • Prevent entry of pathogens

         - Remove pathogens that pass thru barriers
• Physical Barrier

  • 1st major level of protection
• Doderlein Bacili: a normal bacteria that lives on our body w/o causing disease
• a.     Mucous Membranes

  • line all systems that open to outside of body
• eye is protected by lacrimal apparatus
• saliva in mouth allows continual flushing of bacteria to stomach
• a.     urine provides continual flushing of bacteria entering urethra
• mostly neutrophils and macrophage (formed from monocytes) migrate to area of infection
• • Simple Phagocytosismany WBC’s travel through blood and tissues and gobble up bacteria and foreign material
• . Chemotaxis

  • chemical attraction to invaders, microbial products, components of WBC’s or damaged cells
• Adherence

  • attachment to surface of foreign material may be hampered by capsules (eg. S. pneumonia, H. Influenza) or M proteins (eg. S. pyogenes)
• Eosinophilscan produce toxinsmost active against parasitc worm
• Natural Killer Cellsthe “pit bulls” of the defense systemanother kind of WBC; not phagocyticpolice the body in blood and lymphpromote cell lysis of virus infected cells or cancer cells
• Inflammatory Responselarger response that prevents spread of infection from localized area

  • DAMAGE TO BODY’S TISSUES CAUSES:,redness, pain, heat and swelling sometimes loss of functionIf Nakita yang apat may darating na inflammatory response
• • Fever kapag nilalagnat may infectionNormal temp is 36 degrees Celsius to 37.4 degrees Celsius, pag 37.5 we have febrile or fever- systemic rather than local responseinvolves coordinated autonomic, neuroendocrine and behavioral responseused by all vertebrates as acute phase reaction to immune challenge
• • Interferon antiviral chemical secreted by infected cellsthey are host cell specific, not virus specific = different tissues in same host produce different interferons
• • Mode of transmissionThe way pathogen is spread from one host to anotherSuch as through droplets, contact or vectors
• SPECIFIC IMMUNITY

  ➢ functionally, the third line of defense against infections

  ➢ non innate, but adaptive:

  1. carefully targeted or recognizes a specific foreign substance and acts to immobilize or neutralize it

  2. amplifies the immune response, complement reactions, etc. against specific pathogen
• antibodies are proteins called immunoglobins
• -        each immunoglobin molecule consists of 4 polypeptide chains joined together to form a “Y” shaped molecule
• DIFFERENT TYPES OF ANTIBODIES

  IgG

  -        most abundant antibody in plasma

  -        75-80% of gamma globulin, abundant sa plasma but nakikita sa ibang organ

   also found in internal secretions
• DIFFERENT TYPES OF ANTIBODIES

  IgM

  -        largest of the antibodies

  -        only found in blood
• Ig A

  -        dimer, found in sevretions, in mucus

  -        10-25% in serum

  -        also found in body secretions: mucus, saliva, urine, milk, tears
• DIFFERENT TYPES OF ANTIBODIES

  Ig E

  -        associated with allergies

  -        causes certain WBCs to release histamine
• Ig D

  -        very low concentrations in serum

  -        levels increase during chronic infections
• natural

  -        immune response is triggered due to natural  exposure to a pathogen

  -        naexpose ka
• artificial (acquired) - bakunhan

  -        Immune response is triggered by a medical procedure, e.g., vaccination

  nabakunahan
• active

  exposure triggers body’s own immune response including memory cells
• passive

  -        more of artificial

  -        subject receives antibodies from another person or animal, rather than making them himself

  -        offers immediate protection, short term