Download IMMUNE SYSTEM

Chapter 7 and 17
The Immune system and
Development and Aging
IMMUNE SYSTEM
IMMUNE SYSTEM
FIGHTS OFF DISEASES
 2 TYPES OF DEFENSES
1. NON-SPECIFIC- GENERAL
INFLAMMATION AND ATTACK
2. SPECIFIC- HIGHLY ACCURATEANTIBODIES AND T-CELLS

ANTIGEN



ANY FOREIGN SUBSTANCE THAT IS
CAPABLE OF ACTIVATING THE IMMUNE
SYSTEM
USUALLY SMALL PARTICLES ON THE
SURFACES OF INVADING CELLS AND
VIRUSES
POLLEN AND MOLD CAN BE ANITGENS
FOR THOSE WITH ALLERGIES
LYMPHATIC SYSTEM
LYMPHOID VESSELS AND ORGANS
1. COLLECT EXCESS CLEAR FLUID
(plasma that leaks out of blood vessels)
AND RETURN IT TO BLOODSTREAM
2. TINY LYMPH VESSELS ABSORB
FATS IN THE SMALL INTESTINE
3. HELPS FIGHT DISEASE

LYMPH VESSELS
FOUND THROUGHOUT THE BODY
 CONTAIN ONE WAY VALVES,
MUSCULAR CONTRACTION PUMPS
FLUID
EDEMA= TOO MUCH FLUID
 LYMPH IN VESSELS EVENTUALLY
DRAINS INTO 2 LARGE VEINS IN THE
BASE OF THE NECK

LYMPHOID ORGANS
Lymph NODES- A CAPSULE LINED
WITH IMMUNE CELLS
SPLEEN- CAPSULE FILLED WITH
BLOOD AND IMMUNE CELLS
THYMUS- where T LYMPHOCYTES
MATURE
RED BONE MARROW- MAKES ALL
BLOOD CELLS
NON-SPECIFIC DEFENSES
FIGHTS CANCER CELLS AND
PATHOGENS- VIRUSES AND OTHER
ORGANISMS THAT CAUSE DISEASE
 SKIN, MUCOUS MEMB., STOMACHPREVENTS ENTRY
 INTERFERON- A CHEMICAL THAT IS
PRODUCED BY A VIRAL INFECTED
CELL- TELLS OTHER CELLS TO
MAKE ANTIVIRAL CHEMICALS

BROKEN SKIN
INFLAMMATORY Reaction
BRADYKININS from damaged cells
 STIMULATE PAIN RECEPTORS
 STIMULATE MAST CELLS which make
HISTAMINES which dilate capillaries
and make them leaky
 MACROPHAGES crawl out of the
dilated capillaries and destroy invaders

SPECIFIC DEFENSES
B- CELLS
 T- CELLS

B-CELLS
MATURE IN RED BONE MARROW
 PRODUCE SPECIFIC PROTEINNS
CALLED ANTIBODIES WHICH BIND
TO ANTIGENS- this either KILLS the
PATHOGEN OR MARKS IT FOR
ATTACK by T-cells
 PLASMA CELLS MAKE ANTIBODIES
MEMORY CELLS ARE DORMANT but
CAN BE REACTIVATED

SPECIFICITY
THOUSANDS OF DIFFERENT TYPES
OF B-CELLS
 EACH TYPE HAS A SPECIAL
ANTIGEN RECEPTOR
 WHEN A CELL’S ANTIGEN BINDS- IT
DIVIDES INTO PLASMA CELLS
(which make antibodies) AND
MEMORY B CELLS

T CELLS
MATURE IN THE THYMUS
 SOME DIRECTLY ATTACK CELLS
THAT BEAR ANTIGENS, OTHERS
STIMULATE B CELLS
 ALSO HAVE SPECIFIC RECEPTORS
 Must be presented with the antigen by
an antigen presenting cell (APC)
 CLONAL SELECTION PRODUCES
KILLER T CELLS AND MEMORY T

ACTIVE IMMUNITY to DISEASE




FROM INFECTION OR VACCINATION
TRIGGERS IMMUNE RESPONSE BY B AND
T CELLS- MAKES MEMORY B, T
NEXT EXPOSURE= secondary exposure
MEMORY B AND T CELLS DIVIDE VERY
QUICKLY AND AN INFECTION CAN BE
FOUGHT OFF QUICKLY
Most of the time you don’t ever feel sick
IMMUNIZATION
VACCINES CONTAIN PARTICLES OF
THE PATHOGEN OR A WEAKENED
OR KILLED PATHOGEN= ANTIGEN
 SMALL POX- ERADICATED by vaccine
in 1970’s, but possible terrorist weapon
 TETANUS, DIPHTHERIA, HEP. B, FLU,
MEASLES, MUMPS, RUBELLA, POLIO

PASSIVE IMMUNITY
ANTIBODIES FROM ANOTHER
SOURCE ARE GIVEN TO A PERSON
 FOUND IN MOTHER’S MILK OR MADE
BY ANOTHER ORGANISM AND
INJECTED
 NO MEMORY CELLS= SHORT TERM
IMMUNITY

ALLERGIES
OVERACTIVE IMMUNE SYSTEM
 SPECIAL BAD TYPE E ANTIBODIES
ARE SOMETIMES PRESENT ON
CERTAIN MAST CELLS
 IF AN ALLERGEN MATCHES THE E
ANTIBODIES THEN THE MAST CELL
RELEASES HISTAMINE- WHICH
CAUSES LEAKY CAPILLARIESRUNNY NOSE itching etc.

ALLERGY RELIEF
SHOTS- INJECT SMALL AMOUNTS
OF ALLERGEN
 TRIGGERS GOOD ANTIBODIES TO
BE MADE
 GOOD ANTIBODIES NEUTRALIZE
ALLERGEN BEFORE IT CAN ATTACH
TO BAD TYPE “E” ANTIBODIES

TRANSPLANT REJECTION
FOREIGN TISSUES OR ORGANS
HAVE FOREIGN CHEMICALS ON
SURFACES OF THE CELLS
 THE BODY NATURALLY ATTACKS
THESE ANTIGENS
 IMMUNOSUPPRESSIVE DRUGS
MUST BE GIVEN IN ORDER TO
PREVENT REJECTION

AUTOIMMUNE DISEASES





The immune system attacks your own cells
MULTIPLE SCLEROSIS- BODY ATTACKS
ITS OWN NERVE CELL COVERINGS
LUPUS BODY ATTACKS ITS OWN DNA
RHEUMATOID ARTHRITIS- JOINTS
TYPE 1 DIABETES- CHILD’S BODY
DESTROYS INSULIN MAKING CELLS IN
THE PANCREAS
DEVELOPMENT AND
AGING
FERTILIZATION
THE UNION OF THE SPERM
NUCLEUS AND THE EGG NUCLEUS
 PRODUCES A DIPLOID CELL CALLED
A ZYGOTE
 TAKES PLACE IN THE OVIDUCTS

STEPS
1. SPERM COME IN CONTACT WITH
THE OUTSIDE LAYER OF THE EGG
2. ACROSOMAL ENZYMES ARE
RELEASED- EATS THROUGH OUTER
LAYER of egg
3. SPERM NUCLEUS ENTERS EGG
CELL
4. SPERM & EGG NUCLEI FUSE
AFTER FERT.
ZYGOTE BEGINS TO DIVIDE
 CELLS GROW (INCREASE IN SIZE)
 CELLS DIFFERENTIATE- CELL
SHAPE CHANGES ACCORDING TO
THE FUNCTION IT IS ASSIGNED

PLACENTA
TISSUE THROUGH WHICH THE
EMBRYO RECEIVES NUTRIENTS
AND GETS RID OF WASTES
 NO BLOOD TO BLOOD CONTACTEMBRYO HAS ITS OWN BLOOD AND
HEART
UMBILICAL CORD- PIPE THAT
CONNECTS EMBRYO TO PLACENTA

EMBRYONIC DEVELOPMENT
0-2 MONTHS (60 DAYS)
 END OF 1ST MONTH- TAIL, LIMB
PADDLES, HEART BEATS, LIVER
PRODUCES BLOOD CELLS
 END OF 2ND MONTH- TAIL GONE,
ALL ORGANS ARE PRESENT
FETAL DEVELOPMENT- 3-9 MONTHS
(61+ DAYS)

BIRTH
FETUS PRODUCES ANDROGENS
 PLACENTA CONVERTS ANDROGENS
INTO ESTROGEN WHICH CAUSES
THE UTERUS TO CONTRACT
 3 STAGES

STAGE 1
MUCOUS PLUG PUSHED OUT OF
CERVICAL CANAL
 AMNIONIC MEMBRANE BREAKS
(water breaks)
 CERVIX DILATES

STAGE 2
STRONG CONTRACTIONS
 BABY USUALLY COMES OUT HEAD
FIRST
EPISIOTOMY- AN INCISION THAT
ENLARGES THE VAGINA
 UMBILICAL CORD IS CUT
 BABY’S FIRST BREATH

STAGE 3

AFTER SEVERAL MINUTES THE
PLACENTA (afterbirth) IS EXPELLED
LACTATION
AFTER DELIVERY THE MOTHER’S
PITUITARY PRODUCES PROLACTIN
 1ST FEW DAYS- COLOSTRUM IS
PRODUCED- THIN YELLOW MILKY
FLUID THAT IS RICH IN PROTEINS
AND ANTIBODIES
 IF CHILD IS BREAST FED- TRUE MILK
WILL BE PRODUCED NEXT

AGING
PROGRESSIVE CHANGES FROM
AGE 20 THAT CONTRIBUTE TO
INFIRMITY, DISEASE AND DEATH
(a depressing definition isn’t it?)

THEORIES
GENETIC- CELLS CAN ONLY DIVIDE 50
TIMES, MUTATIONS, FREE RADICALS
GENERAL WEARING OUT- EX. TYPE 2
DIABETES
EXTERNAL FACTORS- DIET, HARMFUL
CHEMICALS LEAD TO CELL DEATH
EFFECTS
SKIN- LESS ELASTIC, FAT CONTENT
DECREASES, LOOSE and WRINKLED
 DECREASED ELASTICITY- OF SKIN,
BLOOD VESSELS, LUNGS
 FATTY PLAQUES- PARTIALLY CLOG
BLOOD VESSELS
 POOR CIRCULATION= LESS BLOOD
AND NUTRIENTS TO ALL OTHER
ORGANS (EX. LIVER, KIDNEYS)

NERVOUS SYSTEM
REACTION TIME INCREASES
 DECREASED BLOOD FLOW CAN
STARVE NEURONS WHICH DIE
EASILY

REPRODUCTIVE SYSTEM
FEMALES- AFTER MENOPAUSE- NON
FERTILE
MALES- SPERM ARE PRODUCED
UNTIL DEATH