1. The Immune System

2. GROUP DISCUSSION WILL FOLLOW!
Why do you think the human body makes a great place for disease causing organisms to grow?
What are some examples of organisms that cause disease?
What are some ways diseases are spread?
In spite of being under constant attack by pathogens, we do not get sick all the time. What organ system is responsible for this?
Think – Pair - Share
Answer the following questions in your science notebooks.
GROUP DISCUSSION WILL FOLLOW!

3. What are we learning today?
Benchmark
Objectives
SC.912.L Explain the basic functions of the human immune system, including specific and nonspecific immune response, vaccines, and antibiotics
I will identify and explain the basic functions of the human immune system, including specific and nonspecific immune responses.

4. What is the essential question?
What are the key differences between non-specific immune response and specific immune response?
Answer: The immune response is targeted toward pathogens it remembers. Memory cells continue to patrol the body’s tissues, circulating through the blood and lymph for long periods of time and responding quickly against pathogens they recognize. The inflammatory response can inhibit the growth of pathogens and stimulate macrophage action, but the inflammatory response is not selective.

5. What Is A Disease?
A disease is any change, other than an injury, that disrupts the normal functions of the body.
Diseases are produced by agents, such as
Pathogenic Agents (bacteria, viruses, and fungi).
materials in the environment, such as cigarette smoke.
Others are inherited (genetics).
Disease-causing germs are called pathogens.
Diseases caused by pathogens are generally called infectious diseases.

6. What are the basics?
Homeostasis is the ability of an organism to maintain a stable internal environment.
Diseases can disrupt this stability.
Your immune system is the organ system that protects your body from disease.
Your body has three different lines of defense against pathogens, or disease causing agents.
To the Teacher: Take time to explain the importance of the circulatory system to the immune system. Ask students why they think the immune system could not function properly without the assistance of the circulatory system? If a pathogen does get into the body, the circulatory system helps fight the infection by transporting the immune system’s specialized cells to the source of infection

7. What are the two types of immune defense?
The immune system includes two general categories of defense mechanisms against infection.
Nonspecific defenses guard against infections by keeping most things out of the body.
Specific defenses track down harmful pathogens that have managed to break through the body’s nonspecific defenses.
To the Teacher: Refer to essential question as students identify the differences between the two types of defense.

8. 1st Line of Defense: Barriers to Infection
Nonspecific
To cause disease, a pathogen must invade the body.
Your body has barriers to keep pathogens out.
Skin provides a protective barrier.
Mucous membranes line up interior surfaces that come into contact with the environment.
Pathogens that are swallowed are likely to be destroyed by your stomach acids.
Sweat and tears contains salts, acids, and enzymes that help kill pathogens in your skin and eyes.
To the Teacher: Ask students for the name of the structure in the pictures. Some students will recognize the Great Wall of China. Add a few factoids like it is over 1500 years old and it is the only man-made structure that can be seen from outer space. Ask students to explain why they think the Chinese built the wall? What organ in our body have a similar function?

9. 2nd Line of Defense: Inflammatory Response (innate)
Nonspecific and innate (born with it)
The inflammatory response is the body’s response to tissue damage.
As soon as pathogen enters your body, damaged tissue releases chemical signal.
Blood vessels expand. What is a consequence of this?
Plasma carries macrophages that engulf and destroy pathogens during phagocytosis
If infection persists, body may increase temperature resulting in a fever. Why?
To the Teacher: OPTIONAL: Using the information on this slide or the animation linked to the image (click on the far right side of image), have students make a graphic organizer in which they summarize the stages of the inflammatory response. You may ask students to include in their organizers the cause-and-effect relationships of the inflammatory response. A sample graphic organizer is shown below:
NOW CLI CK TO THE
RIGHT OF THE PICTURE
Inflammatory response
is triggered by
damaged or infected cells
consume invading pathogens
which causes
which release
which attracts
chemical alarm signals
increased capillary permeability
which cause
white blood cells
blood vessel dilation
which
which causes
which causes
suppresses bacterial growth
which
swelling
temperature increases

10. Interferon
are proteins made and released by host cells in response to the presence of pathogens such as viruses, bacteria, parasites or tumor cells.
They allow communication between cells to trigger the protective defenses of the immune system that eradicate pathogens or tumors.
They increase the ability of uninfected host cells to resist new infection by virus

11. 3rd Line of Defense: Immune Response (acquired)
Specific and Acquired (it learns as you mature)
The immune response attacks specific pathogens using specialized cells and proteins.
T cells are white blood cells that attack and kill harmful bacteria or other T cells can activate B cells.
B cells are white blood cells that make antibodies.
An antibody is a Y-shaped protein that attaches to a specific foreign substance, known as an antigen.
bind to the pathogen's membrane proteins
cause pathogen to clump together
weaken the pathogen's membrane
To the Teacher: Have students who have had chickenpox raise their hands. Have them keep their hands raised if they had it more than once. Ask them to explain why most, if not all, hands went down in response to the second question.

12. An immune response produces memory cells.
Next time that pathogen invades your body, your memory cells are ready to fight the infection. They destroy the pathogens so quickly, you usually don’t even get sick.

13. Primary vs Secondary response
Notice the secondary response for antigen A is more rapid and much stronger than the primary response. This is because of the plasma memory cells release the antibodies more quickly than the B- cells in when they first encounter the antigen (primary response)

14. Role 1st Stomach acid and digestive enzymes destroy many pathogens
Line of defense
Nonspecific Defense
Role
1st
Skin
Most important nonspecific defense
Acts as a barrier to infection
Engages in chemical warfare
Mucus membrane
Covers internal body surfaces that come in to contact with the environment
Contains glands that secrete mucus
Traps pathogens in the nose and throat
Cilia
Found in the respiratory tract
Helps to trap pathogens.
Sweat/Oil/Acid
Tears
Body secretions
Stomach acid and digestive enzymes destroy many pathogens
Oil and sweat glands in the skin produce an acidic environment that kills many bacteria.
Antibacterial enzymes are found in saliva and tears

15. Inflammatory response
Line of defense
Nonspecific Defense
Role
2nd
Inflammatory response
(innate immunity)
Reaction to tissue damage caused by injury or infection. (see complement below)
Produces millions of WBC’s to fight infection or injury
Macrophages/phagocytes
Histamine is released to increase swelling in the area
Fever
Body or pathogen releases chemicals that increase the core body temperature
An elevated temperature stops the growth of pathogens.
Interferon
Attack Virus
Tell other cells to be ready for virus attack so they can keep the virus out
Complement proteins
Are proteins released from damaged cells that help clear pathogens from the body and bring white blood cells to infected area (chemotaxis)

16. (adaptive immunity, acquired immunity, learned immunity )
Line of defense
Example of Specific Defense
3rd
Immune Response
(adaptive immunity, acquired immunity, learned immunity )
T cells are white blood cells that attack and kill harmful bacteria. (cell mediated – cell are involved)
B cells are white blood cells that make antibodies. (humural – antibodies are involved)
An antibody is a Y-shaped protein that attaches to a specific foreign substance known as an antigen.
bind to pathogen's membrane proteins
cause pathogen to clump together
weaken the pathogen's membrane
Destroy pathogen

19. THE IMMUNE ANIMATION

20. What are we learning today?
Benchmark(s)
SC.912.L Explain the basic functions of the human immune system, including specific and nonspecific immune response, vaccines, and antibiotics. (AA)
SC.912.L.14.6 Explain the significance of genetic factors, environmental factors, and pathogenic agents to health from the perspectives of both individual and public health.
HE.912.C.1.4 Analyze how heredity and family history can impact personal health.
HE.912.C.1.8 Analyze strategies for prevention, detection, and treatment of communicable and chronic diseases.
Students will…
Identify and/or explain the basic functions of the human immune system, including specific and nonspecific immune responses.
Describe how the human immune system responds to vaccines and/or antibiotics.
Explain the significance of genetic factors, environmental factors, and pathogenic agents to health from the perspective of both individual and public health.

21. Essential Question
Your body has several lines of defense against disease. Explain your body’s mechanisms for keeping you healthy. (include nonspecific and specific response)

22. What is Smallpox? Smallpox was once found throughout the world.
Caused illness and death wherever it occurred.
Smallpox spreads easily from one person to another.
People were once vaccinated against this disease.
The United States stopped giving the smallpox vaccine in
In 1980, the World Health Organization (WHO) recommended that all countries stop vaccinating for smallpox.
The vaccine is no longer given to the general public because the virus has been wiped out. Or has it?

23. The last naturally occurring case of smallpox was diagnosed on 26 October 1977.
In ordinary type smallpox the bumps are filled with a thick, opaque fluid and often have a depression or dimple in the center.

24. What is an Acquired Immunity?
More than 200 years ago, the English physician Edward Jenner wondered if it might be possible to produce immunity against smallpox.
Jenner knew that people who had been affected by a mild disease called cowpox developed an immunity to smallpox.

25. What is an Acquired Immunity?
Jenner took fluid from one of the sores of a cowpox patient and put the fluid into a small cut that he made on the arm of a young farm boy named Jamie Phillips.
Two months later, he injected Jamie with fluid from a smallpox infection and …
The rest is history.
Briefly discuss medical ethics?

26. What is an Acquired Immunity?
The injection of a weakened form of a pathogen to produce immunity is known as vaccination.
Today, more than 20 serious human diseases can be prevented by vaccination.
Modern vaccines stimulate the immune system to create millions of plasma cells ready to produce a specific types of antibodies.
The type of immunity produced by the body’s reaction to a vaccine is known as active immunity.
May develop as a result of natural exposure to an antigen or from deliberate exposure to the antigen.
Flu shot, small pox vaccine, Hep B

27. What is a Passive Immunity?
If antibodies produced by other animals against
a pathogen are injected into the bloodstream, the antibodies produced a passive immunity against the pathogen.
Passive immunity lasts only a short time because eventually the body destroys the foreign antibodies.
Natural passive immunity occurs when antibodies produced by the mother are passed to the offspring during development or in early infancy through breast milk.
Deliberate passive immunity occurs when travelers to certain regions of the world are given vaccines before leaving home.

28. Fighting Infectious Diseases
Because prevention is not always possible, drugs have been developed for the use against some types of pathogens.
Antibiotics are compounds that kill bacteria without harming the cells of the human or animal host and work by interfering with the cellular processes of microorganisms.
Antibiotics have no effect on viruses.

29. What is Methicillin-resistant Staphylococcus aureus (MRSA)?
Is a bacterium responsible for several difficult-to-treat infections in humans.
MRSA is any strain that has evolved resistance to antibiotics, which include the penicillins (methicillin, dicloxacillin, ampicillin, oxacillin, etc.)
Resistance does make MRSA infection more difficult to treat thus more dangerous.
MRSA is especially troublesome in hospitals and nursing homes, where patients with open wounds, invasive devices, and weakened immune systems are at greater risk of infection than the general public.

30. Mueller Hinton agar showing MRSA resistant to oxacillin disk
A ruptured MRSA abscess

31. Infectious Situation Body’s Line of Defense
Bacteria and pathogen on skin surface
Skin cells with no gaps or cuts keep out pathogens. Sweat acids kill bacteria. Pathogens shed with old skin.
Pathogens in nose, mouth, or eyes
Pathogens in digestive tract
Pathogens in burn or cut
Influenza virus enters body for second time
Chickenpox virus enters body for second time
Measles virus enters body soon after measles vaccine
Rabies pathogens enter body from rabid dog bite

32. Essential Question
Your body has several lines of defense against disease. Explain your body’s mechanisms for keeping you healthy. (include nonspecific and specific response)