Download Immunity From Disease

IMMUNITY FROM DISEASE
CHAPTER 39
DISEASE
• DISEASE-ANY CONDITION THAT IMPAIRS THE NORMAL FUNCTIONING OF THE BODY
• VIOLATION OF HOMEOSTASIS
• HOMEOSTASIS-ABILITY OF THE BODY TO KEEP PROPER INTERNAL CONDITIONS NO MATTER WHAT IS HAPPENING
OUTSIDE OF IT
• CAN BE INFECTIOUS OR NON-INFECTIOUS
• INFECTIOUS DISEASES ARE TYPICALLY CAUSED BY PATHOGENS
• BACTERIA, PROTISTS, FUNGI, VIRUSES, PRIONS, WORMS, ETC.
• NON-INFECTIOUS DISEASES ARE USUALLY THE RESULT OF ERRORS WITHIN THE BODY
• CANCER, HEART DISEASE, ETC.
• THE LINE BETWEEN THE TWO IS BLURRY
• SOME INFECTIOUS AGENTS CAN LEAD TO NON-INFECTIOUS DISEASES
• VIRUSES CAN ALTER THE CELL CYCLE AND LEAD TO CANCER
INFECTIOUS DISEASES
• ANY DISEASE CAUSED BY THE PRESENCE OF PATHOGENS IN THE BODY
• CAN BE TRANSMITTED TO OTHERS
• CONTAGIOUS-DISEASE THAT SPREADS FROM ONE ORGANISM TO ANOTHER THROUGH CLOSE
PROXIMITY
• DOES NOT EVEN REQUIRE CONTACT
• COMMUNICABLE-DISEASE THAT CAN SPREAD FROM PERSON TO PERSON, BUT NOT USUALLY SPREAD
THROUGH EVERYDAY CONTACT
• EXAMPLE: HERPES
THE GERM THEORY OF DISEASE
• PEOPLE ONCE THOUGHT THAT SPIRITS CAUSED DISEASE
• HOLES WERE DRILLED IN INFECTED PEOPLE’S HEADS IN AN ATTEMPT TO RELEASE THE EVIL SPIRITS
• IN 1857, FRENCH SCIENTIST LOUIS PASTEUR MADE THE CONNECTION BETWEEN
MICROORGANISMS AND DISEASE
• HE HYPOTHESIZED THAT THE DISEASE COULD BE ELIMINATED IF THE ORGANISM WAS ELIMINATED
• MANY PEOPLE DID NOT ACCEPT THE THEORY
JOSEPH LISTER
• 1865
• BRITISH SURGEON
• NOTICED THAT ABOUT ½ OF HIS PATIENTS DIES FROM INFECTIONS, EVEN AFTER SUCCESSFUL
SURGERY
• HEARD ABOUT PASTEUR’S THEORY AND BEGAN DOING SOMETHING DRASTIC
• WASHING HIS HANDS…
• THE NUMBER OF INFECTIONS DROPPED DRAMATICALLY (NEARLY 0)
• HE PUBLISHED HIS CRAZY HAND-WASHING IDEA AND ENCOURAGED HIS STUDENTS AND
FELLOW SURGEONS TO PRACTICE MORE SANITARY METHODS
• YES, LISTERINE IS NAMED AFTER HIM
ROBERT KOCH
• 1883
• GERMAN PHYSICIAN
• FOUND THAT HE COULD MAKE ORGANISMS SICK BY INJECTING IT WITH PATHOGENS FROM A
SICK ANIMAL
• CAME UP WITH 4 CONDITIONS THAT MUST BE MET BEFORE ONE CAN CONCLUDE THAT THAT A
CERTAIN PATHOGEN CAUSES A DISEASE
• CALLED KOCH’S POSTULATES
KOCH’S POSTULATES
1.
THE PATHOGEN MUST BE FOUND IN EVERY CASE THE DISEASE IS FOUND
2.
THE PATHOGEN MUST BE ISOLATED AND GROWN IN A PURE CULTURE
3.
HEALTHY ORGANISMS INFECTED WITH THE CULTURE MUST DEVELOP THE DISEASE
4.
THE PATHOGEN MUST BE ISOLATED FROM THE SECOND ORGANISM AND FOUND TO BE
IDENTICAL TO THE FIRST
SPREAD OF INFECTIOUS DISEASES
• THE MAIN SOURCE OF HUMAN PATHOGENS IS THE HUMAN BODY ITSELF
• CARRIERS-SOMEONE WHO PASSES THE ILLNESS ON WITHOUT BEING INFECTED THEMSELVES
• SOME DISEASES CAN BE TRANSMITTED BY OTHER SPECIES
• ZOONOTIC DISEASES
• OTHER DISEASES CAN BE FOUND IN THE ENVIRONMENT
• DIRT, WATER, ETC.
TRANSMISSION OF DISEASE
• CAN BE TRANSMITTED 4 WAYS
1. BY DIRECT CONTACT
2. BY AN OBJECT
3. THROUGH THE AIR
4. BY AN INTERMEDIATE ORGANISM
• CALLED A VECTOR
INNATE IMMUNITY
• SKIN AND BODY SECRETIONS
• SKIN IS THE FIRST BARRIER AGAINST INFECTION
• THE ORGANISM MUST GAIN ENTRY TO YOUR BODY TO INFECT YOU
• MUCUS, SKIN OIL, SWEAT, TEARS, AND SALIVA ALSO PROTECT YOU
• ALL HAVE THE ABILITY TO BREAK DOWN THE CELL WALL OF BACTERIA
• INFLAMMATION OF BODY TISSUES
• LOCAL REDNESS, SWELLING, PAIN, AND HEAT
• WHITE BLOOD CELLS RELEASE HISTAMINE
• HISTAMINE DILATES BLOOD VESSELS, ALLOWING OTHER W.B.C. TO COME AND ATTACK THE INVADERS
INNATE IMMUNITY CONTINUED
• THE WHITE BLOOD CELLS THAT COME IN RESPONSE ARE PHAGOCYTES
• PHAGOCYTES ARE CELLS THAT ARE ABLE TO ENGULF AND DESTROY PATHOGENS (CALLED
PHAGOCYTOSIS)
• LYSOSOMAL ENZYMES DIGEST THE PARTICLES
• AFTER KILLING THE PATHOGENS, THE PHAGOCYTES DIE
• THE COLLECTION OF DEAD WBC AND FLUIDS FORM PUS
• INTERFERONS (PROTECTIVE PROTEINS) ALSO HELP PROTECT AGAINST VIRUSES
ACQUIRED IMMUNITY
• DEFENSE AGAINST A SPECIFIC PATHOGEN BY GRADUALLY BUILDING UP A RESISTANCE TO IT
• 2ND LINE OF DEFENSE AGAINST DISEASE
• TWO KINDS OF IMMUNE RESPONSES:
• ANTIBODY IMMUNITY AND CELLULAR IMMUNITY
ANTIBODY IMMUNITY
• ONE TYPE OF ACQUIRED IMMUNITY
• 1ST, YOUR INNATE IMMUNITY DOES ITS JOB
• PHAGOCYTES ATTACK THE PATHOGEN
• THEY THEN DISPLAY THE ANTIGENS (FOREIGN PARTICLES THAT INNATE AN IMMUNE RESPONSE) ON THEIR
SURFACE.
• HELPER T CELLS HAVE RECEPTOR CITES THAT RECOGNIZE AND BIND TO THE ANTIGENS
• PLASMA CELLS SECRETE ANTIBODIES
• THE ANTIBODIES ATTACH TO AND NEUTRALIZE PATHOGENS
• THEY THEN CALL PHAGOCYTES TO HELP DESTROY NEUTRALIZED PATHOGENS
CELLULAR IMMUNITY
• SIMILAR TO ANTIBODY IMMUNITY
• DOES NOT PRODUCE ANTIBODIES
• CREATE KILLER T CELLS (CYTOTOXIC)
• THESE T CELLS ATTACH TO AND LYSE (DESTROY) PATHOGENS
ALLERGIC REACTIONS
• IF YOUR IMMUNE SYSTEM OVERREACTS TO FOREIGN SUBSTANCES (SUCH AS DUST OR
POLLEN), IT CAN RELEASE MASSIVE AMOUNTS OF HISTAMINES
• THESE CAUSE THE SYMPTOMS OF ALLERGIC REACTIONS
• SNEEZING, INCREASED MUCUS PRODUCTION, REDNESS
• YOUR BODY CAN ALSO MISTAKE YOUR OWN CELLS AS FOREIGN AND ATTACK YOUR OWN
TISSUES
• CALLED AN AUTOIMMUNE DISORDER
• ARTHRITIS
• CAN ALSO ATTACK TRANSPLANTED TISSUES
PASSIVE AND ACTIVE IMMUNITY
• ACQUIRED IMMUNITY CAN BE ACTIVE OR PASSIVE
• PASSIVE IMMUNITY
• ANTIBODIES CAN BE TRANSFERRED FROM MOTHER TO CHILD THROUGH PLACENTA
• INJECTING ANTIBODIES FROM OTHER ORGANISM IMMUNE TO THE DISEASE
• OCCURS WITH ANTIVENOMS
• ACTIVE IMMUNITY
• CAUSED BY EXPOSURE TO ANTIGENS
• RECOVERING FROM AN INFECTION
• VACCINES
• INJECTING DEAD, WEAKENED, OR INCOMPLETE PORTIONS OF PATHOGENS TO CAUSE AN IMMUNE RESPONSE
EDWARD JENNER
• DEVELOPED THE FIRST VACCINE
• SMALLPOX
• INJECTED COWPOX, A LESS HARMFUL, YET SIMILAR, DISEASE, INTO A CHILD
• THEN INJECTED THAT CHILD WITH SMALLPOX, AN EXTREMELY DEADLY DISEASE
• THE CHILD DID NOT GET INFECTED
• SAVED MANY, MANY LIVES