Transport of substances in animals briefly. Transfer of nutrients in plants and animals

Remember

1. What substances do cells consist of?
2. How do substances enter cells?

In unicellular animals, for example, in the common amoeba and slipper ciliates, the transfer of substances is facilitated by the constant movement of the cytoplasm.

The cells of multicellular animals receive all the substances necessary for life from the tissue fluid that washes them. In worms, insects and other invertebrate animals, this fluid circulates throughout the body and is called hemolymph. The most advanced system for transporting substances is the circulatory system. Many animals have it.

In vertebrates, blood is separated from tissue fluid. She moves on blood vessels and serves as an intermediary between tissue fluid and the external environment. Blood continuously brings oxygen and nutrients to every living cell, and carries away carbon dioxide, excess water, and unnecessary metabolic products formed in the cells.

The blood of vertebrates, including humans, consists of liquid blood plasma and the formed elements contained in it: red blood cells, platelets and leukocytes (Fig. 59). Red blood cells are involved in the process of respiration; the iron-containing protein hemoglobin gives them their red color. It is involved in oxygen transport. Leukocytes perform protective functions in the body of animals and humans, destroying bacteria and viruses that have entered the body.

Rice. 59. Plasma and formed elements of blood

In animals, hemolymph and blood are the main carriers nutrients and oxygen, as well as a means of removing metabolic products from the body. The movement of hemolymph and blood through the vessels is ensured by a special organ - the heart. It works like a pump.

In the earthworm, the functions of the heart are performed by several thick annular vessels located in the front of the body. In insects, the dorsal vessel is divided into chambers. It communicates with the body cavity through openings with valves that allow blood to flow in only one direction (forward) and close when the blood flows back.

Fish have a heart consisting of two muscular chambers. They contract in turn and forcefully drive blood to the gills.

Birds and animals have a more complex heart, consisting of four chambers - two atria and two ventricles (Fig. 60).

The importance of transport of substances in the body of animals. Almost all animals have a special system for the transport and distribution of substances in the body. The exceptions are coelenterates and flat and roundworms. Inside the body of these organisms, substances travel such small distances that they can easily move by diffusion. In planaria, for example, the intestine is highly branched, and its branches extend to all parts of the body (Fig. 4.10), which shortens the path of nutrients to the cells.

As body size and structural complexity increase, the amount of substances entering the body also increases. The distances that substances have to travel also increase, and simple diffusion is no longer sufficient for their distribution. In this regard, in the process of evolution animals have formed circulatory system- a system of vessels through which

fluid circulates (blood, hemolymph). The circulatory system serves to transport not only nutrients, but also gases involved in the respiration process, breakdown products, hormones, antibodies and salts. In addition, in warm-blooded animals (birds, mammals), heat is transferred and evenly distributed in the body through the bloodstream, which helps maintain a constant body temperature and prevents overheating of deeply located organs.

Basic elements of the circulatory system. Animals have different groups developed different types of circulatory systems in organization. However, they contain basic elements that perform similar functions in all animals.

1. The main contractile organ that serves to push blood through the body’s circulatory system. In most cases, this body is heart.

2. Arterial system, responsible for the distribution and delivery of blood from the heart to all organs and tissues and thus playing the role of a pressure reservoir.

3. capillaries, due to which the transfer of substances occurs between the blood and the cells of various tissues of the body.

4. venous system, representing a reservoir for blood and ensuring its return to the heart -

In all animals, unidirectional blood flow (from the heart to the arteries, then to the capillaries, veins again to the heart) is ensured due to the presence of valves, and the lumen of the vessels is regulated by the work of the smooth muscles of the vascular walls, which makes it possible to control the amount of blood flowing through one or another vascular bed , and thereby redistribute blood flow in the body.

Types of circulatory systems. In [animals there are two types of circulatory system - closed And open (not closed).

At closed circulatory system blood circulates in a closed cavity, within which it spreads from the heart through conducting vessels to organs and tissues and then, without leaving this cavity, returns to the heart (Fig. 4.11). This system is characteristic of annelids, chordates and some other groups of animals.

Cyclostomes and fish (except lungfish) have one circulation. Lungfishes (most of them are extinct; modern ones are represented by six relict species) and terrestrial vertebrates have two circulations.

In many invertebrates (molluscs, arthropods) The circulatory system is not closed. In this case, the hemolymph is ejected by the heart through the artery into the body cavity and, without entering the capillaries, directly washes the tissues. There are no veins through which blood would return to the heart, so from the body cavity blood flows directly into the heart, passing through valves that open at the moment his relaxation (Fig. 4.12).

The most important features of an open-loop circulatory system are usually low blood pressure, difficulty regulating its distribution, and slow return of blood to the heart. In this regard, the closed circulatory system is more dynamic.

Most animals and humans have everything substances obtained or allocated them to letkas, transported with blood. U In some animals, the blood moves in a system of closed vessels (closed circulatory system), in others - by cavity

bodies and partly from osudam (open circulatory system ).

1. Why did animals need to develop a circulatory system?

1. What elements of the circulatory system perform similar functions in all animals?

3. What are the differences in the structure of closed and open types of circulatory systems and the features of their functioning?

Methodological development of a biology lesson in 6th grade according to the program N.I. Sonin in the technology of developing critical thinking. Includes lesson notes, presentation, electronic homework for distance learning.

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Target: to develop knowledge about the characteristics of the transfer of substances in the body of unicellular and multicellular animals.

Tasks:

Educational:repeat the features of the transfer of substances in the body of plants, identify the importance of the transfer of substances and oxygen in the life of animals, study the structural features of the circulatory system, the composition of the blood.

Educational: continue to develop the skills to compare and draw conclusions, use educational literature, solve problematic issues, and make diagrams.

Educational: cultivate a caring attitude towards flora and fauna.

Lesson type: combined.

Equipment: textbook drawings, computer, interactive board, TsOR

During the classes

Testing students' knowledge.

Solving biological problems:

1. Why is it recommended to trim the side shoots of tomatoes and grapes? Why should young tree trunks be protected from damage by rodents? How are they protected?
2. In the spring, the gardener discovered two damaged trees. The mice partially damaged the bark of one, and the hares gnawed the trunk of another in a “ring.” Which tree can die? Why?
3. In Eucalyptus trees growing in Australia, water rises through the vessels to a height of up to 100 m. What contributes to this?

Completing test tasks according to options (5 minutes).

Call.

Transport of substances occurs in all living organisms. What is its significance?

How does it occur in unicellular and multicellular animals?

Why is the epigraph of the lesson the words of Rosenblat, “The elixir of life” is blood?”

Since ancient times, interest in blood has not been accidental. Significant blood loss, when wounded, caused loss of consciousness or loss of consciousness. They worshiped blood, swore friendship and love with blood, washed away shame and insults with blood. Do all organisms have it? How did it come about? Where is it located in the body?

Understanding.

Let us consider the features of the transport of substances in unicellular animals using the example of amoeba. Treat this single-celled organism with respect. This is roughly what our distant ancestors once looked like.

In an amoeba, as a result of its movement, the cytoplasm flows from one part to another. The substances contained in it are mixed and distributed throughout the cell.

The mechanisms of substance transfer are similar to those in plants, however, in addition to passive transport, active transport also appears (video). Why are pinocytosis and phagocytosis possible only in animal cells? The marine environment - the cradle in which life originated and served its children for a long time vehicle, delivering everything they needed to their cells. But as animals developed, they became more complex. And then a remarkable transformation took place (of course, not immediately, but over millions of years) the organisms enclosed part of the water that surrounded them inside their bodies, creating their own “plumbing”. Gradually, the captured sea input changed and turned into an amazing liquid circulating through the circulatory system. This is how the world acquired blood.

Even under a microscope, nothing is visible in the blood, only a thick red veil. But if the blood is diluted two hundred times and then dropped onto a microscope slide, a picture will be revealed that delighted the Dutchman Leeuwenhoek.

Working with the “Structure of Blood” diagram. Watch the video “Structure of Blood”.

Students find the functions of blood and plasma cells in the textbook on page 80 and write them down in their notebooks.

Without hemoglobin, blood dissolves 70 times less oxygen. How can cells destroy microbes?

What is blood? Formulate a definition.

Students examine frog and human blood samples under a microscope and propose hypotheses about the reasons for the differences in the number and size of red blood cells.

There are animals in the world - pure aristocrats the color of blood. These are scorpions, spiders and octopuses. Instead of hemoglobin, they have a pigment containing not iron, but copper.

And their blood is not really blood, but hemolymph.

Recording the term in a notebook.

Why is the hemolymph not involved in the transfer of gases in insects?

Which organ system is directly related to the transport of substances?

The beating of the heart and the movement of blood were already known ancient man, but these processes have been studied

were only in the XVI-XVII centuries.

For almost twenty centuries, science was dominated by Aristotle's erroneous idea that blood and heat are formed in the heart. The English physician William Harvey first explained the circulation of blood through the circulatory system, and this was a real feat, a revolution in science. The thorny path was passed before the facts now familiar to every schoolchild became known. List these facts without repeating yourself.

Introduction to the structure of the circulatory system. Students identify the differences between vessels using the textbook text on page 81 and write the definitions in their notebooks.

In vertebrates, the circulatory system is organized according to a single “plan”. Everyone has a closed circulatory system, blood, vessels and heart.

In the atria, blood collects from the veins, then enters the ventricles, and the contraction of the latter pushes it into the arteries, through which it disperses throughout the body, carrying oxygen and nutrients.

And in insects, crustaceans, and mollusks, the circulatory system consists of blood vessels and the heart. Hemolymph flows through them. Which, like blood, carries nutrients and oxygen. But unlike the system of earthworms, in these animals hemolymph flows from the vessels into the spaces between the organs - the body cavities. Then it again enters the vessels and the heart. Such a circulatory system is called open. Video fragment “The circulatory system of crustaceans.” Working with drawings (determining the type of circulatory system of various animals).

In humans and many other animals, the lymphatic system also participates in the transport of substances.

The lymph circulating in it contains white blood cells and cell waste products filtered from the intercellular substance. The lymphatic system pumps excess water from tissues and returns it to the blood.

Homework instructions:pp. 80-81 in the textbook, learn the terms by heart.

Reflection.

What new did you learn in today's lesson?

What surprised you?

What questions would you like answered?

Completing the test task in notebooks.

Preview:

Movement of substances in the animal's body.

1. Study the textbook article on pp. 80-81 and the presentation on the transport of substances in the animal’s body.
2. Write down in your notebook and memorize the definitions of the terms: phagocytosis, pinocytosis, blood, hemolymph, heart, arteries, veins, capillaries, atrium, ventricle of the heart, closed circulatory system, open circulatory system.
3. Fill in the diagrams in your notebook:

Function: function: function: function:

________ ________ _________ __________

Circulatory system

heart

vessels

atrium

1. Solve a crossword puzzle on the topic “Transport of substances in the animal’s body”:

1. A substance that gives blood its red color.
2. Vessels carrying blood from the heart.
3. What does the circulatory system consist of?
4. The smallest vessels.
5. What circulates through the vessels?
6. What is the name of blood in insects and mollusks?
7. Department of the heart.
8. The circulatory system, in which blood flows only through vessels.

Task "Expertise"

The criminal, in order to hide traces of the crime, burned the victim's bloody clothes. However, a forensic examination based on ash analysis established the presence of blood on the clothing. How?

Movement of substances in the body of animals The “elixir of life” is blood. V. V. Rosenblat.

Transport of substances in the body of unicellular animals 1) Passive: diffusion, osmosis, filtration - removal of water and some substances from a solution. Amoeba vulgaris 2) Active: phagocytosis – absorption of solid particles by the cell; Inocytosis is the absorption of liquid droplets by a cell.

Blood Venous – saturated with carbon dioxide Arterial – saturated with oxygen Transport of substances in the body of multicellular animals

Composition and functions of blood Blood platelets blood cells plasma (intercellular substance) red (erythrocytes) white (leukocytes) (platelets)

Hemolymph (from the word "hema" - blood and lat. "lymph" - pure water) is a liquid that performs functions similar to those of blood. Colorless Blue Yellow Green Purple Red

William Harvey (1578-1657) English physician who described the structure and functions of the circulatory system and the process of blood circulation

Structure of the circulatory system Circulatory system heart vessels atrium ventricle arteries veins capillaries

Arteries are vessels that carry blood away from the heart. Veins are vessels that carry blood to the heart. Capillaries are the smallest blood vessels.

Types of circulatory systems Amoeba vulgaris Closed Unclosed

pp. 80-81 in the textbook, memorize the entries in the notebook. Homework:

1. The organ system responsible for the transport of substances: a) digestive; b) circulatory; c) respiratory. 2. Blood composition: a) plasma only; b) plasma and blood cells; c) only blood cells. 3. The protective function is performed by: a) red blood cells; b) plasma; c) white blood cells. 4. The vessels that carry blood from the heart are called: a) veins; b) arteries; c) capillaries. 5. The heart of birds and mammals: a) three-chambered; b) two-chamber; c) four-chamber. 6. The exchange of substances between blood and tissues occurs in: a) veins; b) capillaries; c) arteries. 7. Mollusks and insects have a circulatory system: a) absent; b) closed; c) open.

Answers to school textbooks

During the transport of substances, they are supplied from places of entry into the body from environment or the places of their formation in the body to the organs that need these substances for life. Thus, in mammals, oxygen entering the lungs is due to transport system is transferred to all cells of the animal body, and carbon dioxide, on the contrary, is transported to the lungs and released into the external environment.

2. How does the transfer of substances occur in unicellular organisms?

In unicellular organisms, various substances are transported by the movement of the cytoplasm. For example, in an amoeba this occurs during its movement, during which the cytoplasm flows from one part of the body to another. The substances contained in it are mixed and distributed throughout the cell. In the slipper ciliate - a protozoan with a constant body shape - the movement of the digestive vesicle and the distribution of nutrients throughout the cell is achieved continuously in a circular motion cytoplasm.

3. What is the role of the circulatory system?

The circulatory system, consisting of vessels, provides blood access to all organs and tissues of the body and carries out one of the most important functions - the transport of substances and gases.

4. What is blood?

5. What does blood consist of?

Blood is one of the types of connective tissue that circulates through the circulatory system. Blood carries nutrients and oxygen throughout the body, and removes carbon dioxide and other waste products. Blood is made up of colorless liquid- plasma and blood cells. There are red and white blood cells, as well as platelets. Red blood cells give blood a red color, since they contain a special substance - the pigment hemoglobin (from the Greek “theme” - blood and the Latin “globulus” - ball). Combining with oxygen, hemoglobin carries it throughout the body. Thus, the blood performs the respiratory function. White blood cells perform a protective function: they destroy pathogens that enter the body. Blood platelets are involved in the process of blood clotting. So, when wounded, thanks to blood platelets, the blood at the wound site coagulates and the bleeding stops.

6. What are stomata, where are they located?

7. How do water and minerals move in a plant?

Water and minerals dissolved in it move in the plant from the roots to the above-ground parts through the vessels of the wood.

8, Which part of the stem does organic matter move through?

Organic substances move from the leaves to other parts of the plant through the sieve tubes of the phloem.

9. What is the role of root hairs? What is root pressure?

10. What is the significance of water evaporation from leaves?

Water enters the plant through root hairs. Covered with mucus, in close contact with the soil, they absorb water with minerals dissolved in it. Then the water rises under pressure through the vessels of the root to other, above-ground organs of the plant. Root pressure is the force that causes One Way water from roots to shoots.

Water evaporates from the surface of leaf cells in the form of steam and enters the atmosphere through the stomata. This process ensures a continuous upward flow of water through the plant. Having given up water, the cells of the leaf pulp, like a pump, begin to intensively absorb it from the vessels surrounding them, where water enters through the stem from the root.