Elementary School Science

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

• The structures and functions of the lymphatic system.

• The three major groups of lymph nodes.

• The role of white blood cells.

• The role of the spleen.

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How will the learning of this content be facilitated?

• The class will begin with the teacher showing the video “The Lymphatic System” (source: https://www.youtube.com/watch?v=tjkHzEVcyrE) The video is only about two minutes long and gives an overview of the function of the lymphatic system. Once the video is over, the teacher should begin a discussion about what the student’s observed in the video/ their reactions to the video. The teacher should show the students the two pictures: the Lymphatic System and Lymph Nodes. The teacher should explain that there are lymph nodes throughout the body. When we go to the doctor, he will feel the front and side of our neck to check for enlarged lymph nodes, which could be the sign of an infection. When we are sick, our neck lymph nodes swell up. The reason they swell is because our body is fighting off an infection.

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• Next, the teacher should hand out the “Organs of the Lymphatic/Immune System” worksheet. If it is possible, project the “The Organs of the Lymphatic/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 write the names of each organ on the line. From this activity, the students will learn about the structures and functions of the immune/lymphatic system.

  • Tonsils & Adenoids: tonsils are located in the throat; adenoids are located high up in the nose. Both help to catch germs that may enter your mouth and nose.

  • Lymph Nodes: small masses of tissue of the lymphatic system. In the lymph nodes, lymph is filtered and lymphocytes are formed.

  • Lymphatic Vessels: structures that carry lymph.

  • Thymus: located in the neck; organ that produces T-cells

  • Spleen: organ that produces and filters out blood.

  • Appendix: tube-shaped sac at the end of the large intestine.

  • Peyer’s Patches: areas of the lymphoid tissue located in the small intestine’s wall; function is to develop immunity to antigens located there.

  • Bone Marrow: located in the cavity of the bones; soft, fatty substance; site of white blood cell production.

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Information Sources:

New Oxford American Dictionary

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• Next, the teacher should hand out the “Our Lymphatic System” worksheet. If it is possible, project the “Our Lymphatic 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 structures and functions of the lymphatic system.

**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**

• Lymphatic System

  • Think of the lymphatic system as a drainage system, like the video mentioned. The lymphatic system helps to filter out any waste, bacteria, or foreign substances in the body.

  • The three major groups of lymph nodes are called: cervical (found on the neck); axillary (found under the arms; armpits); inguinal (found in the groin; lower abdomen).

  • The lymphatic system helps to keep the fluid levels in the body balanced. The lymphatic system also helps to defend against infections.

  • Lymph vessels carry lymph—a clear, watery fluid that contains protein, salt, glucose, urea, and other substances. Lymph relies on the movement of muscles around it.

  • The spleen is located under the ribcage in the upper left part of the abdomen. The spleen’s job is to clean out old red-blood cells and other foreign substances.

  • The lymphatic system takes the extra lymph from our body tissues and returns it to the blood.

  • Our tissues would swell if the lymphatic vessels did not remove the excess fluid.

  • The lymphatic system also helps fight against germs and bacteria.

  • When germs enter the body, they are filtered out by our lymph nodes.

  • Each lymph node, which is a mass of tissue, contains lymphocytes (white blood cells).

  • White blood cells make antibodies, which help to fight against infections and kill the germs that can make us sick. The spleen, which also houses lymphocytes as well macrophages (another white blood cell), helps to trap foreign substances and destroy them.

 

Information Sources:​

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

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• To build upon the functions of the lymphatic system, the teacher begin explaining how a healthy lymphatic system works. The teacher and students will both have a completed copy of “How Our Lymphatic System Works” worksheet. If it is possible, project the “How Our Lymphatic System Works” worksheet onto the board using a projector or put into a PowerPoint document and project so that the teacher can point while they explain.

**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**

• Lymph fluid drains into the lymph capillaries (tiny vessels)

• The fluid is pushed when the muscles contract.

• The lymph vessels are very thin and have many opening. Lymph fluid goes through the openings, nourishes the surrounding cells, and takes away any bacteria. This is called interstitial fluid. The interstitial fluid is collected by the lymph vessels and is emptied into the large veins in the upper chest.

• Lymph enters the lymph nodes and any bacteria/ foreign substance is destroyed by the macrophages.

• Once the fluid is “clean” it is returned to the bloodstream.

 

Information Source: http://kidshealth.org/en/parents/spleen-lymphatic.html#

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• The teacher should next begin a discussion about some of the pathologies of the lymphatic system. It is important that the teacher explain that not all pathologies/illnesses of the lymphatic system are cancer. The teacher should hand out the “Pathologies of the Lymphatic System.” If it is possible, project the “Pathologies of the Lymphatic 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. From this activity, the students will learn about some of the pathologies/ illnesses that can affect the lymphatic system.

**Refer to the teacher’s copy of the worksheet**

 

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

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• Once the lymphatic system pathologies are explained, the students will break into groups of three or four. Each student will be given a “What’s the Diagnosis?” worksheet. On desks throughout the room will be “Patient Cards”. The cards are scenarios of patients that are experiencing problems associated with their lymphatic system. The students will work together as a group and determine what the patient’s diagnosis is. The students will write the diagnosis on their “What is My Diagnosis?” worksheet. Allow the students about 15 minutes to go around the room and “examine the patients”. Reconvene when 15 minutes is over and review the worksheet. The answers to the worksheet are:

• Bob: tonsillitis

• Jill: splenorrhagia

• Roxanne: lymphadenitis

• Billy: splenomegaly

• Jackie: lymphedema

 

• 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 lymphatic system? How many groups of lymph nodes do we have? What is lymph? Why does our body have lymph? What would happen if we didn’t have a lymphatic system?