Elementary School Science

Input:
What is the most important content in this lesson?
To reach this lesson’s objective, students need to understand:

• The functions of the immune system.

• The four types of immunity.

• The role of leukocytes.

• How pathogenic organisms cause diseases in humans.

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How will the learning of this content be facilitated?

Prior to the start of the lesson, enlarge the “Organs of the Lymphatic/Immune System” worksheet and laminate. Also laminate the “Organs” cards. Place the “Organs of the Lymphatic/Immune System” worksheet onto the board or a wall.

**If you prefer, you can add Velcro to the “Organs” cards and “Organs of the Lymphatic/Immune System” worksheet.**

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• Begin the lesson with a review of the “Organs of the Lymphatic/Immune System”. Show the students the “Organs of the Lymphatic/Immune System” and the “Organs” cards. Hold up one card, say what organ it is, and have the students tell you where on the diagram it belongs. Once all of the organs have been placed onto the diagram, the teacher will review what the students know about the lymphatic system. From that discussion, the teacher should introduce the immune system.

 

• The teacher should hand out the “Our Immune System” worksheet. If it is possible, project the “Our Immune System” worksheet onto the board using a projector or put into a PowerPoint document and project so that the teacher can point while they explain. As the teacher explains, the students should fill in the blank spots on their worksheet. From this activity, the students will learn about the functions of the immune system.

**The student worksheet does not contain all of this information. Use this as a guide to help explain the immune system more in depth to the students**

 

• The immune system is made up of special cells, tissues, organs, and proteins that all work together to help the body maintain good health and to protect the body from harmful substances.

• Harmful substances that can affect the body include:

  • Pathogens: disease-producing microorganisms

  • Allergens: substances that cause allergic reactions

  • Toxins: poisonous, harmful substances

  • Malignant Cells: life-threatening, cancer-causing cells

• If bacterium does get into the body, the immune system works to destroy it.

• Immune response is what we call the immune system attacking foreign substances/ bacteria/ illnesses that may enter the body.

• Leukocytes, or white blood cells, are stored in the thymus, spleen, and bone marrow. They are also housed in lymph nodes.

• Leukocytes travel around the body through the lymphatic vessels and blood vessels.

• The two main groups of leukocytes are: phagocytes and lymphocytes.

  • Phagocytes: absorbs invading bacteria; neutrophil is a common phagocyte that helps to fight bacteria.

  • Lymphocytes: allows the body to remember invaders that had entered the body and helps the body destroy those invaders.

  • B Lymphocytes: secrete antibodies (tell the T lymphocytes what invaders to destroy)

  • T Lymphocytes: produced by the thymus gland; helps to destroy the invaders.

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• Humans have four types of immunity:

  • Natural: the immunity that a fetus receives from its mother.

  • Innate: the immunity we are born with. We cannot contact some of the diseases that affect animals, even if we come in contact with that disease. For example, feline leukemia or distemper.

  • Adaptive: the immunity we receive through vaccines. For example, measles immunization or flu shot.

  • Passive: the immunity borrowed from another source. For example, breast milk antibodies help to protect a baby in his/her early life. Younger children need to build up immunity to germs. As we get older, our body becomes immune to more germs.

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Information Sources:

• Medical Terminology for Healthcare Professionals by Ann Ehrlich and Carol L. Schroeder. © 2012.

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• To build upon the immune system, the teacher should introduce how the immune system attacks an invader. The teacher should hand out the “How the Immune System Works” information sheet. The teacher and students will both have a completed copy of “How the Immune System Works” information sheet. If it is possible, project the “How the Immune System Works” information sheet onto the board using a projector or put into a PowerPoint document and project so that the teacher can point while they explain. As the teacher explains, the students should fill in the blank spots on their worksheet. From this activity, the students will learn how the immune system attacks invaders.

**The student worksheet does not contain all of this information. Use this as a guide to help explain the lymphatic system more in depth to the students**

• Antigens or foreign substances, invade the body.

• Once the body recognizes the antigens, cells respond.

• B-lymphocytes produce antibodies or special blood proteins that counteract the antigens.

• Antibodies stay in a person’s body once they are produced. If the antigens invade the person’s body again, the body already knows how to react to them.

• Immunizations place an antigen into a person’s body, but do not get them sick. Instead, it helps to correct antibodies so that if that antigen invades the body, it already knows how to react them. For example, children receive a chicken pox shot to prevent them getting chicken pox. The immunization contains a live virus that is injected into the body via a needle. The body then begins to create antibodies.

• Antibodies cannot destroy the antigens on their own; this is why we have T-cells. The T-cells are the cells that destroy the antigens.

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• Next, the teacher should introduce “Pathogenic Organisms”. If it is possible, project the “Pathogenic Organisms” worksheet onto the board using a projector or put into a PowerPoint document and project so that the teacher can point while they explain. While the teacher explains, the student will fill in the boxes. From this activity, the students will learn about some of the pathogenic organisms that can affect the body. The teacher should explain that “pathogen” means germ. Pathogens enter the body and make you sick. This is why it is important that hands are always washed. Examples of pathogens include:

• Virus: very small; consist of DNA with protein-coated covering; live by invading other cells; examples include: measles, common cold, hepatitis, and the flu.

• Bacteria: small microorganisms; examples include: tuberculosis, typhoid fever, tetanus, and cholera.

• Parasites: organisms that live off their hosts (body they are in); examples include:  scabies, sleeping sickness, and malaria.

• Fungi: microorganisms; examples include: fungal meningitis, thrush, and ringworm.

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• Once the worksheet and information sheet explained, the students will break into pairs. Each student will be given an “Under the Microscope” worksheet and pictures. The pictures are of each organism mentioned on the “Pathogenic Organisms” worksheet. The students need to look at the picture and the name of the pathogen and then decide which column it belongs in. The students will cut and glue only the pictures into the correct column. (the names are used only to help the students identify which pathogen it is) Then, the students will discuss with their partner their observations about the pictures they saw “under the microscope. For the first 10 minutes, the students will not be allowed to use their worksheets. For the last 5 minutes, the students should be allowed to use their worksheets”. Allow the students about 15 minutes to work together. Reconvene when 15 minutes is over and review the activity.

 

• The final assessment will be for the students to answer the question:

Think about what you learned about today in class. What is the function of the immune system? How is immune system similar to the lymphatic system? What cells “tell” the body there are invaders? What cells attack the invaders? What is a pathogen? How many groups of pathogens are there?