Activity 5.3.1: To Drain and Protect

Introduction

In this unit, you have taken a look at the barriers, skin and bone, and accessory organs and secretions that protect the body from injury and initial invasion by pathogens. Now you are going to take a deeper look at the body system that functions todrain and distribute fluid in the body, and to protect the human body against specific invaders – the lymphatic and immune system.

When you think of transportation of fluid around the body, you probably think of the network of blood vessels in the circulatory system. But the body has another transportation system – the lymphatic system. The lymphaticsystem consists of organs, ducts, and nodes and transports a watery clear fluid called lymph.Up to three liters of fluid remain behind in the tissues and must be returned to the blood each day. Lymph vessels interact with the circulatory system to drain this fluid from your cells and tissues. Lymph also distributes immune cells around the body. White blood cells called macrophages and lymphocytes, that are also found in the blood, form the body’s immune system – your most powerful defense weapon. These cells initiate highly specific responses directed against particular microbes, such as viruses or bacteria or abnormal cells, such as cancer cells, and protect the body while it is under attack.

In this lesson, you further explore the body’s defenses and study the way in which specific cells can target and destroy invaders. But first, let’s take a look at the system that makes this all possible. In this activity, you will investigate the basic structure of the lymphatic and immune system and add these organs, glands and tissues to a graphic organizer. You will research the pathways of lymph vessels and the location of lymph nodes and build these structures on your Maniken®. You do not want your Maniken® to get sick, so let’s get started.

Equipment

  • Computer with Internet access
  • Anatomy in Clay®Maniken®
  • Green clay
  • Spaghetti gun and extruder
  • Body system graphic organizer handout
  • Colored pencils or markers
  • Laboratory journal
  • Reference textbook (optional)

Procedure

  1. Obtain a body system graphic organizer from your teacher and label it “Lymphatic and Immune System.”
  2. Research the lymphatic and immune system and draw and label at least five essential organs, tissues or glands on your graphic organizer. The following websites may help start your search.
  • NIH Medline Plus – Immune System Structures
  • Discovery Health – How the Immune System Works
  1. Add a text box for each structure on your organizer that describes the role that the structure plays in the lymphatic and immune system. Draw arrows from each structure to the appropriate text box.
  2. Answer conclusion questions 1 and 2.
  3. Using websites or reference textbooks, find a graphic that shows the path of lymph vessels and lymph nodes in the body. Your teacher may provide you with a reference graphic.
  4. Create clay spaghetti strands using green clay. Notice that the strands you are creating are thinner than those you used for arteries, veins and nerves. Hang the strands over your desk so they do not get tangled. Your teacher may have already created these strands for you.
  5. Add a lymphatic system to yourManiken® that includes:
  • A simple representation of lymph vessel webbing and branching on the arm, chest and neck.
  • Placement of lymph nodes (use small “seeds” of green clay) along the axillary (armpit), mammary (breast) and throat regions.
  1. Remember that lymphatic vessels travel with arteries and veins. Find major vessels such as the subclavian artery, the carotid artery and the femoral artery and use the path of these vessels along with your diagram to assist with placement. Do not worry about perfect placement.General structure is the same, but we each have a unique immune system.
  2. If you have not already done so, draw some lymph vessels and nodes on your graphic organizer.
  3. If you have extra time, add lymph vessels to the leg and add lymph nodes in the inguinal (groin) region.
  4. Answer the remaining conclusion questions.

Conclusion

  1. Why is red bone marrow considered part of the immune system?
  1. The walls of lymph vessels are extremely thin. How does this structure relate to function?
  1. Explain how the lymphatic system assists with movement around the body?
  1. Since movement of the lymphatic fluid is not fueled by a pump, such as the heart, how do you think this liquid is propelled around the body? (HINT: Think back to some of the features of veins that helped blood fight back to the heart.)
  1. What is the function of the lymph nodes? Why are they often inflamed or swollen when we get sick?
  1. Why do you think the defense mechanisms we have discussed thus far in this unit are considered “non-specific” resistance? What do you think is meant by specific resistance?

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Human Body Systems Activity 5.3.1 To Drain and Protect – Page 1