Today is Thursday, February 19 th, 2015 Pre-Class: How many
tiers does the immune system have? (take a guess) Also, whats the
best way to make your immune system more effective? In This Lesson:
Immunology (Lesson 3 of 3)
Slide 2
Todays Agenda The Immune System Including all three levels of
response. Antibodies Immunity Where is this in my book? Chapter
43.
Slide 3
By the end of this lesson You should be able to narrate the
immune response to a pathogen with details for each of the three
levels. You should be able to distinguish between five general
types of white blood cells with detail given to the four main types
of lymphocytes. You should be able to describe the five classes of
immunoglobulins.
Slide 4
Perspective This is the part where I try to give you guys
inspiration or motivation to learn. Ill be honest with you and this
is not a joke to me this is one of the most beautiful things in
biology. Think about it weve learned about evolution and all the
amazing ways organisms have developed to become more efficient at
life. Now we look at a part of the body that has had, by far, the
most intense selective pressures for the longest evolutionary
time.
Slide 5
Perspective Now youre going to witness conflict on a molecular
scale. Quite literally, this is a battle for resources between an
invader and the body. Watch as cells interact with one another with
one side trying to outdo the other and exploit weaknesses. The best
part? Nothing is actually conscious. Its nothing short of
brilliant. Its nothing short of amazing.
Slide 6
The Germ Theory Today, were well aware of germs. We know that
things we cant see can hurt us. However, there was a time when the
idea of a microscopic pathogen was laughable. Its the 1860s. Enter
Louis Pasteur.
Slide 7
The Germ Theory Louis Pasteur (same dude as the pasteurization
process) takes on a centuries-old debate about the nature of
disease. He shows that disease is caused by bacteria through:
Breakdown of tissue. Toxin release. Further, disease can be
transmitted by: Air Water Food Contact Invertebrates (especially
insects) Louis Pasteur
Slide 8
The Germ Theory So the Germ Theory is born. The Germ Theory
simply states that microscopic organisms are capable of causing
disease. So, no more is it the vapors making women ill.
http://www.broadsheet.ie/wp-content/uploads/2011/06/mlady.gif
Slide 9
Fast forward to 1890 Robert Koch, considered the father of
modern bacteriology, puts forth Kochs Postulates to connect a
pathogen to a disease. A researcher must: Find the same pathogen in
all diseased organisms. Isolate and grow the pathogen in a lab.
Sicken healthy animals with the pathogen. Isolate the same pathogen
from the newly- infected organism and grow it again.
http://upload.wikimedia.org/wikipedia/commons/thumb/8/8d/RobertKoch_cropped.jpg/190px-RobertKoch_cropped.jpg
Robert Koch
Slide 10
Kochs Postulates
Slide 11
Disease Transmission With the Germ Theory comes five modes of
disease transmission: Direct contact Example: Infectious
mononucleosis, chlamydia. Indirect contact A surface that transfers
disease like a doorknob a sick person touches that infects someone
else is a fomite. Example: The common cold. Aerosol [large
water/mist droplet] Example: Respiratory viruses. Airborne [small
droplet] Example: Measles, tuberculosis, chicken pox, smallpox.
Vector [other organism or food] A vector is another organism that
transfers a disease. Example: E. coli, listeria, bubonic plague.
http://phprimer.afmc.ca/Part3-PracticeImprovingHealth/Chapter11InfectiousDiseaseControl/Modesandcontroloftransmission
Slide 12
Case-in-Point: Typhoid Mary This is Mary Mallon (1869-1938),
better known as Typhoid Mary. Let me tell you why she doesnt look
happy. She carried typhoid fever but was completely asymptomatic.
She also happened to work as a private cook for families. Whoops.
Because of her job, she continuously made people ill. Over the
course of her career she infected 51 and is linked to at least 3
deaths, but possibly up to 50. She is also quoted to have said she
did not understand the purpose of hand washing and refused to give
up her job as a cook. She was forcibly quarantined by the City of
New York twice and died after almost 30 years in isolation. It
appears that Salmonella typhi may hide in white blood cells called
macrophages.
http://upload.wikimedia.org/wikipedia/commons/e/eb/Mary_Mallon_%28Typhoid_Mary%29.jpg
Mary Mallon
Slide 13
Immune System So along with the advancement of bacteriology,
science also began to turn its attention to immunology (how your
body defends itself). Whats your bodys first line of defense? The
first line of the immune system? The boundaries of your body.
Slide 14
Infection Thus, the points of entry for a pathogen include:
Digestive system Respiratory system Urogenital tract Breaks in skin
(including cuts, eyes, ears) Infection can then spread via: The
circulatory system The lymphatic system
Slide 15
Lines of Defense Summary Slide 1 st Line: Barriers Skin, mucus
membranes, secretions. 2 nd Line: Non-Specific Broad, internal
defense. Known as the innate response. 3 rd Line: Specific Acquired
immunity specific to the pathogen. Known as the adaptive/acquired
response.
Slide 16
First Line of Defense: External Examples The trachea/windpipe
is lined with cells that have cilia (to sweep out pathogens) and
mucus (to stop them). Tears and saliva wash pathogens away and have
lysozymes (enzymes that damage bacterial cell walls). Sweat (pH
3-5) and stomach acid (pH 2) denature proteins.
Slide 17
Infection Once a pathogen enters your body, its up to your
immune system to fight it off. After all, youre a nice environment
for a pathogen. Youre warm. Youre packed with nutrients. You dont
even have cell walls! Pathogens can then circulate viathe
circulatory system. Luckily, you have an alternate circulatory
system for the immune system called the lymphatic system.
Slide 18
The Lymphatic System
Slide 19
Production of Red/White Blood Cells Inflammatory Response Fight
ParasitesShort-lived Phagocytes (most white blood cells) Become
Macrophages
Slide 20
Second Line of Defense: Internal White blood cells, broadly
known as leukocytes, are actually several different cells.
Furthermore, they have equivalents that exist within tissues that
dont circulate but play similar roles. Theres also other stuff that
floats around, plus the blood liquid itself. Heres a guide Mast
Cell Macrophage Neutrophil Natural Killer Cell
Slide 21
Blood Plasma and Blood Serum Blood plasma is the liquid in
blood, not including the blood cells. It includes clotting factors
like fibrinogens. Blood serum does not include fibrinogens.
Slide 22
Blood Components Fibrinogens Proteins that help in clotting.
Platelets Cells that help in clotting. Erythrocytes Red blood cells
[RBC] carry oxygen. 4.8-5.2 million RBC per milliliter of human
blood. Leukocytes White blood cells [WBC] immune system.
4000-10,000 WBC per milliliter of human blood. Five major classes.
http://bme.virginia.edu/ley/leukocytes.html
Slide 23
The Five Types of Leukocytes 1.Neutrophils (40%-75% of WBC)
Live for about three days. Find their way to infection site by
chemoattractants. Ingest and destroy bacteria. 2.Eosinophils (1%-6%
of WBC) Live for weeks. Move to infection site via chemoattractants
and kill bacteria. Defend against multicellular invaders (like
worms). http://bme.virginia.edu/ley/leukocytes.html