Biology lesson 9 anatomy lymphatic system. Lymphatic system

The internal environment of the body is formed by blood, lymph and intercellular (tissue) fluid. There is constant exchange between these liquids, so their composition differs. Lymph consists of a liquid part and formed elements. Lymph contains proteins, glucose, minerals, fats. Amount of proteins and fats in to a large extent depends on food intake and amount of water drunk. The composition of ions and their quantity is the same as that of blood plasma. TO shaped elements lymph includes lymphocytes, and to a lesser extent macrophages.

The interaction of blood and cells is carried out through tissue fluid, which washes all cells. There is a constant exchange of substances between cells and tissue fluid.

There, between the cells, the blind-closed capillaries of the lymphatic system begin. Once the fluid enters the capillaries, the intercellular fluid becomes lymph. The amount of lymph in the human body is approximately 1-2 liters.

The mechanism of lymph formation Arrows indicate the direction of movement of fluids The constant movement of fluids has important. For example, the constancy of physical and chemical properties organism. This constancy is maintained even with very strong external influences. Self-regulation, the ability of the internal environment of the body to maintain the constancy of its internal state called homeostasis. The concept of homeostasis includes maintaining chemical composition internal environment, as well as physical parameters, for example, temperature, heart rate, respiration. Maintaining this consistency is necessary for normal operation the whole body.

§ 2 Functions of the lymphatic system

The body's lymphatic system performs a series of important functions:

Is a system of additional outflow between tissue fluid from organs;

Lymph nodes found along the path of fluid outflow are biological filters in which foreign elements and microorganisms are disinfected and retained;

V lymph nodes B-lymphocytes mature and enter the blood, producing antibodies;

Absorption of fats from the small intestine occurs in the lymphatic capillaries;

Capillaries circulatory system are not able to pass large protein molecules from the intercellular space, so they first enter the lymphatic duct, and then into blood vessel.

Let's look at the structure of the lymphatic system.

The lymphatic system originates from capillaries that penetrate all organs and tissues. The walls of the capillaries are formed by a single layer adjacent to the surrounding tissues. The capillary wall has a large number of pores through which intercellular fluid flows out. The capillaries enlarge, forming first small ones and then larger ones. large vessels. They merge into the thoracic lymphatic duct, which flows into the subclavian vein. The lymph thus combines with the blood.

§ 3 Lymph nodes

Lymph nodes are of great importance for the human body.

A lymph node is a peripheral organ of the lymphatic system that functions as a biological filter through which lymph flows from organs and parts of the body.

Lymphs have an oval or bean-shaped shape and sizes from 0.5 to 50 mm. They are educated connective tissue. The inflowing lymph brings foreign antigens that enter it from the intercellular fluid.

Macrophages and B-lymphocytes carry out immune response reactions, i.e. carry out phagocytosis (capture and digestion of solid particles) and form antibodies.

Lymph nodes are located in clusters near blood vessels in such a way as to be in the path of infection. They can be found in the elbow bend, in armpit, in the knee bend, as well as groin area. The lymph nodes of the neck provide protection against infections and tumors of the head and organs located in the neck. Great amount lymph nodes are located in the abdominal and thoracic cavity.

What promotes the movement of lymph? Lymphatic capillaries have valves that can open and close, allowing intercellular fluid to pass into the capillary. Intercellular fluid is continuously formed in the body. Its pressure is greater than the pressure of the lymph in the lymphatic vessels. Therefore, intercellular fluid enters the capillary. Another reason for the movement of lymph is the suction action. chest during inhalation. Reduction smooth muscle walls lymphatic vessels and reduction skeletal muscle- this is the third reason for the movement of lymph. The reverse flow of fluid is prevented by semilunar valves located along the vessels.

§ 4 Brief summary of the topic of the lesson

1. Lymph includes proteins, glucose, minerals, fats, water, lymphocytes, macrophages.

2. The chemical composition of lymph depends on the amount of water and food taken by a person.

3. The constant movement of lymph in the body maintains its homeostasis.

4. The lymphatic system performs a number of important functions: removes excess water from tissues, filters microorganisms and foreign elements, transports fats and large protein molecules.

5. The movement of lymph is unidirectional - it begins in the intercellular space and ends in the circulatory system.

6. A lymph node is a biological filter.

7. The movement of lymph is facilitated by: the continuous formation of fluid in the body; suction action of the chest during inhalation; contraction of the smooth muscles of the lymphatic vessels and skeletal muscles.

Images used:

During this lesson we will learn about how lymph circulates through our vessels. Let's talk about their structure and functioning.

Subject:Blood and circulation

Lesson: Movement of Lymph

The main function of the lymphatic system is to remove poisons and toxins from the human body. Thus, it is directly involved in human immunity.

The lymphatic system consists of lymph nodes and lymphatic vessels (see Figure 1).

Rice. 1.

Lymphatic vessels resemble veins in structure (see Fig. 2). They have elastic walls and valves that prevent the reverse flow of liquid.

Rice. 2.

Lymph moves through the vessels, enters the thoracic duct, and from there into the neck veins, where it merges with the bloodstream.

Lymph is formed as a result of the absorption of tissue fluid into the lymphatic capillaries (see Fig. 3).

Rice. 3. Lymph formation

Lymph circulates through the vessels, passing through the lymph nodes.

That is, lymph is one of the fluids that forms internal environment body, whose composition resembles blood. It does not contain red blood cells and platelets, but large quantities there are lymphocytes.

Lymph flow is provided by the muscles surrounding the lymphatic vessels. They contract, pushing blood upward. And the reverse flow of liquid is prevented by valves in the vessels. Thus, lymph is in constant movement.

Bibliography

1. Kolesov D.V., Mash R.D., Belyaev I.N. Biology. 8. - M.: Bustard.

2. Pasechnik V.V., Kamensky A.A., Shvetsov G.G. / Ed. Pasechnik V.V. Biology. 8. - M.: Bustard.

3. Dragomilov A.G., Mash R.D. Biology. 8. - M.: Ventana-Graf.

Homework

1. Kolesov D.V., Mash R.D., Belyaev I.N. Biology. 8. - M.: Bustard. - P. 105, tasks and question 2, 3.

2. What are lymph nodes made of?

3. What is lymph and how is it formed?

4. Prepare a short report on diseases of the lymphatic system.

Biology lesson in 8th grade. "___"____ 20____

Movement of lymph.

Target. To give students an idea of the structure of the lymphatic system.

Educational. Study the structure of the lymphatic system; show the relationship between the lymphatic and circulatory systems.

Developmental. Continue to develop the skills to analyze, compare, draw conclusions based on the results of work, work with tables, perform laboratory work according to instructions, observe, decide problematic issues

Educational. Cultivate a caring attitude towards your health.

During the classes.

Org. moment.

Repetition of learned material.

Frontal survey.

Slide 2. Complete the diagram.

Slide 3. Which blood vessel is shown in the picture?

What functions does it perform?

Slide 4. Which blood vessel is shown in the picture?

What is its structure?

What functions does it perform?

Slide 5. Which blood vessel is shown in the picture?

What structure does it have, what is indicated by numbers?

What functions does it perform?

Slide 6. List the parts of the heart shown in the picture numbered 1-6.

Slide 7. What phase of the heart is shown in the figure?

Paperwork.

Slide 8. Match the parts of the heart indicated by numbers and the names indicated by letters.

Slide 9. Fill in the missing words.

The pulmonary circulation begins in (1)... ventricle and ends in (2)... atrium.

The great circle begins in (3)... ventricle and ends in (4)... atrium.

IN pulmonary artery(5) ... blood flows, and through the pulmonary veins - (6) ... .

There is blood in the left atrium and ventricle (7) ... .

There is blood in the right atrium and ventricle (8) ... .

The transformation of venous blood into arterial blood occurs in (9) ... in (10) .... the circulatory system.

Studying a new topic.

The circulatory system is not the only vascular system in our body. In most organs in the human body, in addition to the blood vessels, there are lymphatic vessels. They contain lymph.

Lymph is a light yellowish liquid of protein nature, contains water, mineral salts, glucose, amino acids, O 2, CO 2. It contains practically no red blood cells and contains much less proteins compared to blood plasma. But it contains a lot of lymphocytes. The amount of lymph in the human body is about 2 liters.

(slide 10) The lymphatic system consists of lymph nodes and lymphatic vessels. Lymphatic vessels are similar in structure to veins. They have elastic walls and valves that prevent the reverse flow of liquid.

It is formed from blood plasma tissue fluid, which washes all cells and tissues, giving them nutrients and oxygen. Then part of the tissue fluid is absorbed into the lymphatic capillaries and forms lymph. Lymphatic capillaries are present in all organs and tissues of the body, except the brain and spinal cord, cartilage and bone marrow. They have a larger diameter than blood capillaries, – up to 0.2 millimeters. Lymphatic capillaries connect with each other and form lymphatic networks.

(slide 11) From the capillaries, lymph enters the larger lymphatic vessels. The movement of lymph occurs from the bottom up, from the tips of the fingers and toes. Therefore on internal walls Lymphatic vessels contain valves that prevent the reverse flow of lymph.

(slide 12) Thanks to the valves, the lymph moves in one direction. In humans, lymphatic vessels end in the right lymphatic and thoracic ducts. Both ducts drain lymph into the superior vena cava great circle blood circulation near the heart. From 1 to 3 liters of lymph return to the blood per day.

(slide 13) Along the course of the lymphatic vessels there are special education – The lymph nodes. Some of them in the form of rounded seals can be found under lower jaw. There are also many of them in the armpits and popliteal cavities, in the groin and among internal organs.(slide 14)

If the lymph nodes retain a lot of bacteria, they increase in size, become inflamed and painful. (slide 15)

The cause of inflammation of the lymph nodes can be infectious and bacterial diseases.

The functions of the lymphatic system are protective, drainage and nutritional. Protective function the lymphatic system is associated with the formation of lymphocytes in its nodes, the production of antibodies and the retention of pathogens various diseases. Removal of excess fluid enters the tissues from the bloodstream through capillary epithelial cells that are loosely adjacent to each other and is ensured by the capillaries of the lymphatic system, which flow into large vessels and, finally, into the veins of the systemic circulation. Lymph also carries some of the lipids that are absorbed into small intestine.

The main function of the lymphatic system is to remove poisons and toxins from the human body.

Thus, the structure of the lymphatic system includes capillaries, vessels, nodes, trunks and ducts. In essence, the lymphatic system is part vascular system body, complementing the cardiovascular system.

Reinforcing the material learned. (slide 16)

Practical work " Oxygen starvation».

Briefly tighten your finger with a pharmaceutical rubber ring, twisting it in a figure eight. Explain the reasons for the observed phenomena. (pp. 84-85)

Observation result
Redness of the finger
Whitening of the finger
Tingling in the finger (feeling like crawling)
Deterioration of finger sensitivity

Homework. § 18

In the category Human Lymphatic System are free videos lessons on this topic. The human lymphatic system is part of the vascular system that complements cardiovascular system. It consists of lymphatic capillaries, vessels, nodes, trunks and ducts. The lymphatic system plays important role in cleansing the cells and tissues of the body, and also participates in metabolism. The lymphatic system, unlike the circulatory system, is open-ended and does not have a central pump. The movement of lymph occurs under the action of human muscles, therefore sedentary lifestyle life negatively affects his health. Studying the lymphatic system using video lessons will be useful for both beginners and more advanced experienced doctors. You can watch online lessons from the Lymphatic System category for free at any time. convenient time. Some video lessons on the lymphatic system include: Additional materials, which can be downloaded. Enjoy your learning!

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Lymph cleansing

This video lesson talks about cleansing the lymph, i.e. human lymphatic system. Toxic poisons enter the body through breathing, nutrition and skin. Then they enter through the blood arterial system and reach the cage. They return through the lymphatic system and enter the venous system and are excreted through the skin, kidneys, liver, digestive system and through the bronchi in the form of mucus. This is a conceptual diagram of purification. Now let's figure out how we can influence it...