Title: The immune system

Author: Zyta Sendecka

Target group

7th grade students of an elementary school.

Core curriculum

6. The immune system. Student:

1) indicates the location (in the diagram, drawing, as per description, etc.) of selected organs of the immune system: spleen, thymus and lymph nodes and determines their functions.

Lesson aim

Students describe the structure of the immune system and explain its role in the body.

Criteria for success

• explain what is the similarity between the composition of blood and lymph;

• you describe the elements that make up the lymphatic system: spleen, thymus and lymph nodes;

• discuss the role of the lymphatic system organs;

• name cells and organs of the immune system.

Key competences

• communicating in the mother tongue;

• communicating in a foreign language;

• digital competence;

• Mathematical competence and basic competences in science and technology; 

• learning to learn;

Methods/forms of work:

Working with the text, a talk, the method of „instant information”, the traffic lights method.

Individual work.

Teaching measures:

• abstract;

• interactive whiteboard or traditional blackboard;

• tablets/computers;

Lesson phases

Introduction

The teacher gives the subject and the purpose of the lesson in a language that the student understands and displays the criteria for success.

Realization

1. The instructor asks the pupils to read the fragments of „Lymph” and „Lymphatic system organs and their role”, and then independently perform interactive exercises No. 2 and No. 3.

2. A student selected by the teacher performs the exercises on the interactive whiteboard and justifies their selected answers. The class assesses the accuracy and addresses possible errors.

3. The teacher asks the students what the similarity of the composition of blood and lymph consists of and what it results in.

4. The teacher presents an interactive illustration „Construction of the immune system.” Volunteers name successive organ systems, discuss their position and role. Teacher verifies the students comments by clicking consecutive numbers included in the illustration.

5. The lecturer asks pupils to read the passage titled „Cells and molecules of the immune system”, and then independently perform interactive exercise No. 1.

Summary

1. Students describe gastrointestinal tract, using the „flash information” method.

2. The teacher displays the criteria of success and asks the pupils to assess the level of their knowledge gained during the classes using the students flip‑board (green means that the students are able to perform all the actions that the success criteria refer to, yellow - that the students are only able to do some of the given activities and they should re‑examine selected sections of the abstract, red - that students are not able to do any of the above‑mentioned activities and must read the abstract again).

Homework

Make at home a note from the lesson using the sketchnoting method.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

The immune system

Even the thinnest blood capillaries can not reach all the cells of the body. Consequently, tissue fluid mediates between the cells and the blood – lymph. It arises as a result of filtration of components of blood plasma from the blood into the space between the cells of the body. Lymph consists of water, mineral salts, proteins, fats and white blood cells. It allows the transfer of nutrients to cells as well as some unnecessary metabolic products to the blood vessels. Takes part in gas exchange between cells and blood vessels. The major part of the lymph returns to the blood vessels. The rest is collected from the inter‑cellular spaces through the capillaries of the lymphatic system. Lymph supports and complements the transport function of blood.

The lymphatic system forms such organs as the: spleen, thymus, lymphatic vessels, papules and lymph nodes, and immune cells and the substances produced by them.

The lymphatic system accompanies the blood system and works closely with it. In contrast, it is open. In the open system, the fluid is in vessels and fills the spaces between the cells. Lymphatic capillaries collecting tissue fluid from the inter‑cellular spaces are dead‑end branches.They merge into larger lymphatic vessels (lymphatic ducts) and eventually drain lymph into veins. Lymphatic vessels, like veins, transport fluid under low pressure, have thin walls and are equipped with valves. The lymphatic movement is forced by muscle cells of the walls of the lymph vessels and the muscles of organs located near these vessels. The lymph flows through the vessels through the lymph nodes. They clean the lymph, catching foreign bodies from it. When more microorganisms appear in the system, the lymph nodes are enlarged. The immune cells present there eat alien bodies.

The largest organ of the lymphatic system is the spleen. Here, white blood cells multiply, and erythrocytes and thrombocytes die. In the chest is the thymus, in which white blood cells mature, among them T lymphocytes (here they acquire the ability to recognize foreign bodies). After age 18, this gland gradually disappears, filling with fat cells.

We owe the body's immunity to white blood cells. There are several types of leukocytes. Bone marrow and lymphatic system result in white blood cells that develop into macrophages and lymphocytes. They participate in the body's immune responses by combating pathogens entering the body. Macrophages they are the largest white blood cells. They have the ability to move through to infected places. They absorb and destroy bacteria, produce substances that inhibit the multiplication of viruses and the development of cancer cells.

Lymphocytes are formed in the bone marrow. Some of them stay here, mature and acquire the ability to fight pathogenic agents. They are B lymphocytes, that go to the blood and produce antibodies recognizing and destroying foreign bodies. Rest of the lymphocytes are T lymphocytes goes from the bone marrow to the thymus. There, it matures and acquires the ability to recognize an intruder, destroy infected cells and cancer cells. T‑lymphocytes also produce substances that stimulate other defense cells of the system to function. Mature B and T lymphocytes circulate in the lymph and peripheral blood.

• The lymphatic system forms such organs as the: spleen, thymus, lymphatic vessels, papules and lymph nodes, and immune cells and the substances produced by them.

• Lymph vessels have a similar structure to veins and capillaries.

• Lymph is a blood filtrate.

• The organs of the lymphatic system, cells and antibodies are responsible for the immune response of the body.

• macrophages and T and B lymphocytes specialize in the destruction of pathogens.