1. Chapter 43 Warm-Up Define the following terms:
Pathogen
Antigen
Antibody
Allergen
Vaccine
What are lymphocytes? Where do B cells and T cells mature?

2. Ch. 43 Review Warm-Up
What is the difference between innate vs. adaptive immunity?
Contrast the functions of B cells and T cells.
How are antigens recognized by immune system cells?
What are memory cells?
How does HIV affect the immune system?

3. DEFENSE! Immunology (Immunology: the scientific study of the way the immune system works in the body, including allergies, resistance to disease, and acceptance or rejection of foreign tissue

4. Why do organisms need an immune system?
Protection from external pathogens (ex: bacteria, viruses, fungi, and parasitic protists)
Enter the body through the following routes: digestive system, respiratory system, urogenital system, or a break in the skin)
Travel through the body using the following transport systems: circulatory system and lymphatic system
Protection from internal attack by abnormal human body cells (ex: cancer cells)

5. Why an immune system? animals must defend themselves against invaders
VIRUSES
HIV, flu, cold, measles, chicken pox, SARS
BACTERIA
pneumonia, meningitis, tuberculosis
FUNGI
Yeast, athletes foot
PROTISTS
amoeba, Lyme disease, malaria
cancer cells
mutated body cells

6. What organs and tissues are considered part of the human immune system?
Lymph vessels = tubes that run parallel to the circulatory vessels (arteries and veins) and serve as a blood filtration system to remove foreign particles
Lymph nodes = oval shaped organs in the armpits, neck, etc. that are connected to lymph vessels ; they collect foreign particles and store B and T lymphocyte cells
Spleen = stores blood cells ; removes clumped pathogens coated with antibodies from the blood stream

7. What organs and tissues are considered part of the human immune system?
Adenoids (aka tonsils) = trap pathogens
Bone Marrow = stem cells within the bone marrow differentiate into blood cells ; location where the B lymphocytes (aka B cells) mature
Thymus = organ in the neck that is used to create and promote maturation of T lymphocytes (aka T cells)

8. These are the parts of the immune System

9. What defenses are most organisms born with?
Plants and all animals have nonspecific (aka innate/natural) immune responses that they are born with ; these responses attack any pathogen that tries to invade the body in the same way
Example in Plants: Hypersensitivity response (cells that come in direct contact with the pathogen undergo apoptosis and signal other nearby cells to improve defenses in their cell walls)

10. What defenses are most organisms born with?
Examples in Humans:
First Line of Defense: External Barriers
Physical Barriers: Skin; mucous membranes in the eyes, nose, anus, etc ; cilia lining the respiratory tract (sweep out pathogens)
Chemical Barriers: Sweat (pH 3-5), tears + saliva (contain an enzyme called lysozyme that digests bacterial cell walls), stomach acid (hydrochloric acid is at pH 2)

11. What defenses are most organisms born with?
Second Line of Defense: Internal Barriers
Leukocytes (phagocytic white blood cells that “swallow” any foreign particle)
Ex: Macrophages
The Inflammatory Response:
-cells release histamine (causes dilation / widening of blood vessels)
-increased blood supply to the injury causes redness, warmth, and swelling
-blood brings leukocytes to the area to “swallow” and digest pathogens

12. What defenses are most organisms born with?
-Fever = widespread inflammatory response; higher body temperature interferes with
bacterial and viral activity
When a local response is not enough
full body response to infection
raises body temperature
higher temperature helps in defense
slows growth of germs
helps macrophages (white blood cells)
speeds up repair of tissues

13. The first line of defense! Broad "external" defense
Physical Barriers
non-specific defense
external barriers
skin & mucus membranes
excretions
sweat
stomach acid
tears
mucus
saliva
“lick your wounds”

14. The first line of defense! Broad "external" defense
Mucous Membranes
Mucous membranes line the interior surfaces of our bodies
Secrete mucous, a sticky fluid that traps pathogens
Respiratory and digestive tract mucous membranes delivers pathogens to the stomach where they are killed
Urinary and reproductive mucous membranes pass pathogens out of the body
Skin
Did you know that skin is the largest and most important organ in the human body?
Provides a physical barrier to pathogens
Releases sweat, oil, and waxes which contain chemicals that kill many pathogens

15. Second line of defense…
Patrolling white blood cells
attack invaders that get through the skin
recognize invader by reading antigen
surface name tag
phagocyte cells
macrophages
“big eaters”

16. Second line of defense…
Non-specific immunity includes:
Inflammatory response
Temperature response
Proteins
Just like the first line of defense (skin and mucous membranes), non-specific immunity is non-specific OR it works the same way against any and all pathogens

17. Why do injuries swell? Inflammation
injured cells release chemical signals called Histamines
increases blood flow
brings more white
blood cells to fight
bacteria
brings more red blood
cells & clotting factors
to repair

18. Inflammatory response
Proteins: Complement proteins circulate in the blood system and kill
pathogens when they encounter them.
Interferons are proteins that are released by cells infected with a
virus to warn nearby cells and help them get ready to resist viral infection

19. What defenses do organisms develop throughout their lifespan?
Vertebrates have specific (aka acquired) immune responses that they develop over time in response to encounters with specific pathogens
Third Line of Defense

20. What defenses do organisms develop throughout their lifespan?
Example in Humans:
A specific type of macrophage called an antigen – presenting cell (aka APC), which is part of the innate immune system, swallows an antigen released by a pathogen, chops it up, and presents it on its cell surface
(Antigen = a molecule (usually a protein or carbohydrate) found on the surface of a pathogen or released by a pathogen that triggers the production of specific immunity molecules called antibodies)
The APC binds with a helper T cell, which initiates the specific immune response

21. What defenses do organisms develop throughout their lifespan?
Helper T cells trigger the differentiation of several types of lymphocytes (specific types of leukocytes, or white blood cells)
B lymphocytes (aka B cells) – come in two forms, plasma B cells and memory B cells
-plasma B cells actively make antibodies to bind to the antigen presented by the original APC
-Antibodies = Y shaped proteins with tips that bind specifically to a particular antigen and cause clumping of multiple antigens; this clumping signals a macrophage to swallow the clump and digest it
-memory B cells are made to prevent an infection by the same pathogen years later; they can be converted quickly into plasma B cells
-B cells are part of Humoral Immunity (regulates destruction of “naked” pathogens in the body fluids – blood, saliva, tears, etc.—that have not yet infected a body cell)

22. B-cells develop in the Bone Marrow

23. What defenses do organisms develop throughout their lifespan?
T lymphocytes (aka T cells, cytotoxic T cells, or killer T cells) – come in two forms, active cytotoxic T cells or memory cytotoxic T cells
-active cytotoxic T cells bind to the antigens displayed on infected body cells and release perforins (protein molecules) to break open the pathogens cell membrane and induce cell death
-memory cytotoxic T cells are made to prevent an infection by the same pathogen years later ; they can be converted quickly into active cytotoxic T cells
-Cytotoxic T cells are part of Cell-Mediated Immunity (regulates destruction of body cells that have been infected by a particular pathogen)

24. T-Cells – develops in Thymus
Gland on Your Heart! How Romantic

25. Why can’t humans “catch” the same infection twice?
Memory B and cytotoxic T cells can quickly develop into plasma B cells and active cytotoxic T cells to rapidly eradicate a pathogen recognized by the body
This is called the secondary immune response.

26. A question released on the 2013 AP Biology practice test that relates to the secondary immune response.
An individual’s humoral response to a particular antigen differs depending on whether or not the individual has been previously exposed to that antigen. Which of the following graphs properly represents the humoral immune response when an individual is exposed to the same antigen more than once?

27. What is the difference between passive and active immunity?
Active immunity involves an individual making his/her own antibodies, which are long-lasting
-Natural = antibodies produced by B cells in response to infection by a particular pathogen
-Artificial = antibodies produced by B cells in response to a vaccine (weakened / killed antigen)
Exposure to harmless version of germ
stimulates immune system to produce antibodies to invader
rapid response if future exposure

28. Jonas Salk 1914 – 1995 Developed first vaccine against polio
April 12, 1955
Poliomyelitis (polio) is caused by a virus that enters the body through the mouth. The virus multiplies in the intestine and invades the nervous system. It can cause total paralysis in a matter of hours.
One in 200 infections leads to irreversible paralysis. Among those paralyzed, 5-10 percent die when their breathing muscles are immobilized.
Polio mainly affects children under age 5.
Poliomyelitis (polio) is caused by a virus that enters the body through the mouth. The virus multiplies in the intestine and invades the nervous system. It can cause total paralysis in a matter of hours.
One in 200 infections leads to irreversible paralysis. Among those paralyzed, 5-10 percent die when their breathing muscles are immobilized.
Polio mainly affects children under age 5.

29. Polio epidemics 1994: Americas polio free
1916 The first major polio epidemic strikes in the United States; 27,000 people suffer paralysis and 6,000 die. Increasing numbers of outbreaks occur each year.
1921 Franklin D. Roosevelt is diagnosed with polio.
1928 Iron lungs are introduced to help patients with acute polio breathe.
1932 Franklin D. Roosevelt is elected President of the United States
1949 Dr. John Enders, Dr. Frederick Robbins and Dr. Thomas Weller develop a way to grow poliovirus in tissue culture, a breakthrough that aided in the creation of the polio vaccine. Their work earned the three scientists the Nobel Prize in physiology and medicine in 1954.
1952 The United States reports 57,628 polio cases -- the worst U.S. epidemic on record.
1979 The last U.S. case of polio caused by wild poliovirus is reported.
1988 Worldwide, polio continues to affect some 350,000 people in 125 countries.
1994 The Americas are certified polio-free.
2000 The Western Pacific region is certified polio-free.
2002 Europe is certified polio-free.

30. Protecting you from disease
Vaccinations
advantage
don’t get illness
long term immunity
produce antibodies for life
works against many viruses & bacteria
disadvantage
not possible against all invaders

31. What is the difference between passive and active immunity?
Passive immunity involves antibodies being transferred from another organism, which are short-lasting
-Natural = mothers pass antibodies to their fetus via the placenta and newborn via breast milk
-Artificial = antibodies produced by a mouse in response to a pathogen can be injected into human tissue to protect against the same pathogen

32. Koch's Postulate
Dr. Robert Koch – first person to establish a clear procedure for identifying pathogens that cause infectious disease
He studied anthrax (a common cattle disease that could be passed to humans)

33. Why is HIV so harmful to the human body?
HIV = human immunodeficiency virus
The HIV virus attacks the body’s Helper T cells, so that the body cannot create new cytotoxic T cells or B cells to fight against other, unrelated infections (ex: pneumonia, tuberculosis)
When the Helper T cell count drops below 200 cells per cubic millimeter of blood, a patient has AIDS (acquired immunodeficiency syndrome) ; normally, a healthy individual’s T cell count ranges from 500 to 1800 cells per cubic millimeter of blood
So in other words, HIV is the virus that causes the condition AIDS
People who have AIDS typically die due to an inability to fight off other infections

34. What are autoimmune diseases?
Autoimmune diseases occur when the T cells and B cells fail to recognize the body cells as “self cells” and attack them as they would a pathogen
Ex:  Auto-immune diseases - immune system attacks own cells
psoriasis
lupus
antibodies attack many different body cells
rheumatoid arthritis
antibodies causing damage to cartilage & bone
Type 1 diabetes
insulin-making cells of pancreas attacked & destroyed
multiple sclerosis
T cells attack myelin sheath of brain & spinal cord nerves
fatal

35. Curing you of bacterial disease
Antibiotics = medicine
advantage
kill bacteria that have successfully invaded you
make you well after being sick
disadvantage
use only after sick
only good against bacteria
possible development of resistance by bacteria (if don’t use correctly)
can get sick again

36. Immune system malfunctions
Allergies
over-reaction to harmless compounds
allergens
proteins on pollen
proteins from dust mites
proteins in animal saliva
body mistakenly thinks they
are attackers