Transcript Natural Killer Cells

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Thank you,
Vicki Hughes
CHAPTER 12:
Lymphatic System
http://www.argosymedical.c
om/Other/samples/animati
ons/Lymph/index.html
Assignments:
OL CH 12 Practice Test
The lymphatic system
carries fluid lost from
capillaries.
Lymph = clear-to-white
fluid made of:
White blood cells,
especially lymphocytes,
the cells that attack
bacteria in the blood
and fluid from the
intestines called chyle,
which contains proteins
and fats.
lymph
Lymph returns to the
blood in the right
lymphatic and
thoracic ducts.
Lymph also transports
the products of fat
digestion, and is a
major component of
the immune system.
Everywhere there are
cardiovascular capillaries,
there are lymphatic
capillaries.
The walls of the
lymphatic vessels act as
one-way valves, only
letting fluid enter.
Once in the vessels, the
lymph is advanced
toward the systemic
circulation.
Along the way, the lymph is filtered through several lymph
nodes where it is inspected for foreign substances.
http://www.youtube.
com/watch?v=mimy
915mpWs
Upon reaching the
thoracic duct, the
lymph re-enters
circulation.
Lymph nodes contain
large numbers of
lymphocytes and
macrophages that fight
invading microorganisms.
Lymphatic Organs
Spleen
• filters blood
• recycles old erythrocytes
• stores platelets and
leucocytes
• fights some bacteria
Spleen
What does the Spleen Do – Harvard
http://www.youtube.com/watch?v=aEi_4Cyx4Uw
Lymphatic Organs
Thymus
• makes T cells
from white
blood cells
formed in the
bone marrow
Lymphatic Organs
Tonsils
• behind tongue
Adenoids
• at back of nasal
cavities
Both tonsils and
adenoids trap
pathogens that enter
through your nose
and mouth.
The Defense System
Foreign Substance = anything Pathogen = harmful or
not endemic to the body
disease-causing microorganism
Common Pathogens: Bacteria
Strep throat
Fastest Around the Track!
Bacteria
Welcome to school!
7:40 a.m.
You are
infected by a
single
bacterium.
Total bacteria in
your body:
1 bacterium
Fastest Around the Track!
Bacteria
Settling into
1st
Period
8:00 a.m.
You feel fine.
Total bacteria in
your body:
10 bacteria
Bacteria
Fastest Around the Track!
Moving toward mid-morning.
9:00 a.m.
You feel fine.
Total bacteria in
your body:
40 bacteria
Bacteria
Fastest Around the Track!
Just after mid-morning.
10:20 a.m.
You feel a
little tired.
Total bacteria in
your body:
5120 bacteria
Fastest Around the Track!
Bacteria
Just after lunch.
1:00 p.m.
You feel sick
and are ready
to go checkout
early.
Total bacteria in
your body:
How Your Body Deals with Bacterial Invasions
http://www.youtube.com/watch?v=M3JGXWoXBnc
http://www.youtube.com/watch?v=_BKK2xlmX0E&feature=relmfu
http://www.youtube.com/watch?v=3lImNGDh5kA&feature=relmfu
1,310,720 bacteria
Bacteria
The Good, the Bad, and the Ugly
Intestinal bacteria processes
vitamin K for humans - GOOD!
E. coli
E. Coli outbreak causes
sickness in hundreds - BAD!
Bacteria
The Good, the Bad, and the Ugly
C. tetani causes tetanus - UGLY!
Clostridium tetani
Common Pathogens: Viruses
HIV
Common Pathogens: Parasites
African eye worm
Flash: Monsters Inside Me
Hookworm
Common Pathogens: Protists
Malaria
African Sleeping Sickness
Mosquito
Trypanosoma
Tse Tse Fly
Plasmodium
Specific vs. Nonspecific Defenses
A. Nonspecific Defense System = immediate response to any
threat
1.
2.
3.
4.
skin
mucous membranes
inflammatory response
proteins
B. Specific Defense System (Immune System) = attacks
specific threats
1. immune cells (lymphocytes and macrophages)
2. special molecules
Nonspecific Defense
First Line of Defense
Surface Membrane Barriers:
1. Acid pH of skin and vaginal secretions – kill bacteria.
2. Stomach HCl and enzymes – kill pathogens.
3. Saliva and lacrimal fluid (tears) containing lysozymes –
kill bacteria.
4. Digestive and respiratory tract mucus traps pathogens.
5. Nonspecific
Nonspecific Defense
First Line of Defense (cont.)
Phagocytes:
Cells that eat foreign particles. (Nonspecific)
1. macrophage = large phagocyte
2. neutrophils = blood born phagocyte
Use lysosomes (vacuoles with digestive enzymes) to digest
particles once they are inside the phagocyte body.
Nonspecific Defense
First Line of Defense (cont.)
Natural Killer Cells (NK cells):
1. “police” the body looking for intruders.
2. Can lyse and kill cancer and virus-infected cells.
3. Can respond to ANY intruder. (nonspecific)
Natural Killer Cells
http://www.youtube.com/watch?v=HNP1EAYLhOs&feat
ure=player_embedded
Nonspecific Defense
Inflamm = set on fire
Second Line of Defense
Inflammatory Response:
1. Nonspecific
2. Four cardinal signs of acute inflammation:
a. Redness
b. Heat
c. Swelling
d. Pain
Nonspecific Defense
Second Line of Defense
INJURY!
Damaged cells
Release inflammatory chemicals (kinins, histamine)
Blood vessels dilate
Capillaries Leak
Clotting
proteins
Increased blood flow
Edema
(fluid in tissue)
Neutrophils
Monocytes
Dead cell/pathogen
clean up
Second Line of Defense
Nonspecific Defense
Clotting
proteins
Increased blood flow
REDNESS
HEAT
Increases
metabolic
rate
Edema
(fluid in tissue)
SWELLING
More
nutrients
& O2
Dead cell/pathogen
clean up
PAIN
Fibrin
barrier
Limited
movement
HEALING
Fever = abnormally high body temperature
Pyrogens = chemicals secreted by white blood cells and
macrophages that cause a rise in body temperature.
When a fever is good:
Bacteria require iron and zinc. During a fever the liver hoards
these minerals. Fever also increases the metabolic rate which
delivers nutrients, white blood cells, etc. to the damage zone.
When a fever is bad:
If a fever gets too high it causes a “scrambling” of enzymes and
other body proteins.
http://www.youtube.com/watch?v=wGVoMMo1KW8
Specific Defense Third Line of Defense
Immune Response
Antigen = receptor on the surface of cells (both harmful cells
and body cells).
Cytotoxic T cell = releases destructive chemicals (cytotoxins).
Memory cell = retains information identifying pathogens that
have been fought before.
Antibodies = inactivate antigens by 3 methods:
1. neutralization = antibodies bind to bacterial exotoxins
or to viruses and block harmful effects.
2. agglutination = mismatched blood or bacteria clumps.
3. precipitation = settling out of unwanted particles.
Specific Defense
Virus infects the cell.
Macrophage eats infected cell.
Macrophage expresses viral antigens.
Expressed antigens trigger Helper T Cells.
Expressed antigens trigger Helper T Cells.
Helper T Cells trigger Cytotoxic T Cells and B Cells.
Cytoxic T Cells travel to the infection site and destroy
infected cells. (Natural Killers circulate all the time and so are not
considered a part of the specific defense system.)
B Cells produce
antibodies.
Antibodies travel
to infection sites
and attach to
receptors on freeroaming viruses
preventing them
from docking with
uninfected body
cells.
Phagocytes clean
up the debris.
Flash: An Inside Look at the Flu
Quiz: Inside Look at the Flu Video
1. What is the first line of defense discussed in the video?
a. Natural killer cells
b. Increase in mucus
c. Production of antibodies by B-cells
d. Attack of T-cells
2. How does the flu virus manage to enter Holly’s throat cell?
a. It is mistaken for a harmless protein.
b. It destroys the throat cell membrane.
c. It dissolves through the cell membrane.
d. It doesn’t enter, it simply inserts DNA into the cell.
3. What is the function of the natural killer cells?
a. Produce antibodies
b. Spray killer toxins
c. Eat viruses
d. Eat waste material
4. What do B-Cells do?
a. Eat viruses
b. Spray killing toxins
c. Produce antibodies
d. Block viral receptors
5. What is the purpose of Holly’s cough?
a. Remove live viruses
b. Remove waste because the cilia is damaged
c. Help fight against the virus
d. Attack T-cells
6. Why is it best for Holly not to take fever reducers?
a. Fevers aid in the fight against the infection.
b. Fevers keep Holly from doing too much while she
recovers.
c. Fevers provide a way for the T-cells to attack.
d. Fevers allow the blood to flow faster.
7. How can you catch the flu?
a. Breathing it in.
b. Drinking or eating it.
c. Kissing.
d. All of the above.
8. Would it have helped Holly to get antibiotics?
a. No, because she didn’t have a bacterial infection.
b. No, because she didn’t have a viral infection.
c. Yes, because she had a fungal infection.
d. Yes, because she had a protist infection.
9. What caused Holly’s whole body to ache even though only
her throat cells were being damaged?
a. The virus was spreading.
b. Macrophages were eating cells.
c. Interleukens were increasing Holly’s sensitivity.
d. All of the above.
10. How will Holly’s body react if she encounters
influenza B again in the future?
a. She will have to fight the disease from scratch all
over again.
b. She will not be infected a second time.
c. Her memory T cells will mount a quicker attack the
next time.
d. She will not have any way to fight the next time
because she used up all of her defenses already.
Diseases of the Immune System
Autoimmune
diseases arise from
an inappropriate
immune response of
the body against
substances and
tissues normally
present in the body.
Addison’s Disease
AIDS
Berger’s Disease
Cushing’s Syndrome
http://app.discoveryeducation.com/
search?Ntt=immune+diseases