New ecopsychologyspiritual ecology. Respiratory system of insects Insects breathe through the entire surface of the body.

In insects, it is the most accurate reflection of their lifestyle. Since these creatures are always above the ground, they breathe exclusively thanks to the tracheae, which are much more developed in them than in other inhabitants of our planet. In fairness, it is worth highlighting that there are some superclasses of insects that live in the aquatic environment, or often go there. In this case, the respiratory system of insects is represented by gills. However, these are extremely rare species of this class, so we will also examine them very briefly. Well, let's move on to a more detailed study of this section of biology.

common data

So, the respiratory system in insects appears to us in the form of trachea. Numerous branches emanate from them, which spread to all vital organs and systems of the body. The whole body, with the exception of the head (that is, the thoracic region and abdomen) is covered with exit holes - spiracles. They form the tracheal system, thanks to which most insects can breathe through the surface of their body.

It is worth noting that these spiracles are reliably protected from environmental irritants by special valves. They quickly react to the flow of air due to well-developed muscles. It is also important to know that spiracles are found on the sides of each body segment. The size of their holes is adjustable, due to which the tracheal lumen changes.

Ventilation process

To understand thoroughly how insects breathe, it is important to first understand that each tracheal system that is located in the body is always ventilated. The necessary air exchange occurs due to the fact that the valves that are located along the body, roughly speaking, open and close according to a certain schedule, that is, coordinated. For example, consider how a similar process occurs in locusts. During the entry of air, the anterior 4 spiracles open (among them two thoracic and two abdominal anterior). At this time, all the others (6 rear) are in the closed position. After air has entered the body, all spiracles close, and then the opening occurs in the following sequence: 6 rear ones open, and 4 front ones remain closed.

Basic breathing movements

Many years ago, scientists, looking at how insects breathe, noticed that their bodies contracted and unclenched in a certain way. This process turned out to be synchronous with the process of oxygen entering the body, and therefore it was concluded that many representatives of arthropods breathe precisely thanks to standard mechanical actions. Thus, the respiratory system in insects can function due to contractions of individual sections of the abdomen. This type of "breathing" is characteristic mainly of all terrestrial creatures. The same individuals who live partially or completely in the water are characterized by a reduction in some of the thoracic regions. It is also important to remember that it is muscle contraction that occurs on exhalation. When air enters the body, all the abdominal and thoracic segments of the insect, on the contrary, expand and completely relax.

The structure of the trachea

It is the trachea, as mentioned above, that represents the respiratory system of insects. For children, such a concept may turn out to be too complicated, so if you explain this biological process to your child, then first tell him what this very respiratory organ looks like. In almost all insects, each trachea is a separately existing trunk. It comes from the valve through which the spiracle passes. Branches emanate from the tracheal tube, which are presented in the form of a spiral. Each such branch is formed from a very dense cuticle, which is always securely fixed in its place. Thanks to this, the branches do not fall off, they do not get tangled, therefore gaps are always preserved in the insect body through which oxygen and carbon dioxide can normally circulate, and without which life of this class is unrealistic.

How are flying insects different?

The respiratory system of insects that can fly looks a little different. In this case, their organisms are equipped with so-called air sacs. They are formed due to the fact that the tracheal tubes expand. Moreover, these extensions are much larger than the original width of the respiratory organ. Another characteristic feature of such bags is that they do not have spiral seals, therefore they behave much more mobile inside the body of an insect. The expansion and contraction of air sacs in flying insects occur passively. During inhalation, the body increases, during exhalation, respectively, it decreases. In this process, only the muscles that control everything are involved. It is also important to note that the respiratory system of flying insects is designed so that they can take in more oxygen for a longer period.

Insects that have gills

Arthropod inhabitants of water bodies, like fish, have gills and gill openings. In this case, the respiratory process is still carried out thanks to the trachea, however, this system in the body is closed. Thus, oxygen from the water enters the body not through the spiracles, but through the gill slits, after which it enters the tubes and spirals. If the insect is arranged in such a way that with the process of growing up it gets out of the aquatic environment, begins to live on the ground or in the air, then the gills become a vestige that disappears. The tracheal system begins to develop more actively, the tubes and spirals become stronger, and the breathing process no longer has anything to do with the gills.

Conclusion

We briefly examined what kind of respiratory system insects have, how it is characteristic, and what varieties of it can be found in nature. If you dig deeper, you can find out that the respiratory systems of arthropods of various categories are very different from each other, and most often their features depend on the habitat of certain species.

How do insects breathe, and do they breathe at all? The body structure of the same beetles differs significantly from the anatomy of any mammal. Not all people know about the features of the life of insects, because it is difficult to observe these processes due to the small size of the object itself. However, these questions sometimes come up - for example, when a child puts a captured beetle in a jar and asks how to ensure a long, happy life for him.

So do they breathe, how is the process of breathing carried out? Is it possible to close the jar tightly so that the bug does not run away, will it suffocate? These questions are asked by many people.

Oxygen, respiration and insect size

Modern insects are really small in size. But these are exceptionally ancient creatures that appeared much earlier than warm-blooded ones, even before dinosaurs. In those days, the conditions on the planet were completely different, the composition of the atmosphere was also different. It's even amazing how they could survive millions of years, adapt to all the changes that have taken place during this time on the planet. The heyday of insects is behind, and in those days when they were at the peak of evolution, it was impossible to call them small.

Interesting fact: the fossilized remains of dragonflies prove that in the past they reached half a meter in size. During the heyday of insects, there were other exceptionally large species.

In the modern world, insects cannot reach this size, and the largest are tropical individuals - a humid, hot, oxygenated climate gives them more opportunities to thrive. Literally all researchers are convinced that it is precisely their respiratory system with its specific device features that prevents insects from flourishing on the planet in today's conditions, as it was in the past.

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Respiratory system of insects

When classifying insects, they are classified as a subtype of tracheal breathing. This already answers many questions. Firstly, they breathe, and secondly, they do this through the trachea. Arthropods are also classified as gill-breathers and chelicerae, the former being crayfish and the latter being mites and scorpions. However, let us return to the tracheal system, characteristic of beetles, butterflies, and dragonflies. Their tracheal system is extremely complex; evolution has polished it for more than one million years. The tracheae are divided into numerous tubes, each tube goes to a certain part of the body - in much the same way as the blood vessels and capillaries of more advanced warm-blooded, and even reptiles, diverge throughout the body.

The tracheae fill with air, but this is not done through the nostrils or mouth, as in vertebrates. The trachea are filled with spiracles, these are the numerous holes that are on the body of the insect. Special valves are responsible for air exchange, filling these holes with air, and closing them. Each spiracle is supplied by three branches of the trachea, including:

• Ventral for the nervous system and abdominal muscles,
• Dorsal for dorsal muscles and spinal vessel, which is filled with hemolymph,
• Visceral, which works on the organs of reproduction and digestion.

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The tracheae at their end turn into tracheoles - very thin tubes that braid each cell of the insect's body, providing it with an influx of oxygen. The thickness of the tracheol does not exceed 1 micrometer. This is how the respiratory system of an insect is arranged, due to which oxygen can circulate in its body, reaching every cell.

But only crawling or low-flying insects have such a primitive device. Flyers, such as bees, also have air sacs like those of birds in addition to lungs. They are located along the tracheal trunks, during flight they are able to contract and inflate again in order to provide maximum air flow to each of the cells. In addition, waterfowl insects have systems for retaining air on the body or under the abdomen in the form of bubbles - this is true for swimming beetles, silverfish, and others.

How do insect larvae breathe?

Most larvae are born with spiracles; this is true primarily for insects living on the surface of the earth. Aquatic larvae have gills that allow them to breathe underwater. Tracheal gills can be located both on the surface of the body and inside it - even in the intestines. In addition, many larvae are able to receive oxygen throughout the surface of their body.

Insects don't have lungs. Their main respiratory system is the trachea. Insect tracheae are communicating air tubes that open outward on the sides of the body with spiracles. The finest branches of the trachea - tracheoles - permeate the entire body, braiding organs and even penetrating inside some cells. Thus, oxygen is delivered with air directly to the place of its consumption in the cells of the body, and gas exchange is ensured without the participation of the circulatory system.

The work of closing devices reduces the loss of water in the process of breathing. (video)

During respiratory movements, they move away from each other and approach each other, and in Hymenoptera they also make telescopic movements, that is, the rings are drawn into each other during “exhalations” and straighten out during “inspirations”. At the same time, the active respiratory movement, which is caused by muscle contraction, is precisely “exhalation”, and not “inhalation”, in contrast to humans and animals, in which the opposite is true.

The rhythm of respiratory movements can be different and depends on many factors, for example, on temperature: in the Melanoplus filly at 27 degrees, 25.6 respiratory movements per minute are performed, and at 9 degrees there are only 9. Before many intensify their breathing, and during it inhalations and exhalations often stop. A honey bee has 40 breaths at rest and 120 when working.

Some researchers write that, despite the presence of respiratory movements, insects do not have typical inhalations and exhalations. We can agree with this, taking into account the peculiarities of a number of taxa. Thus, in locusts, air enters the body through the anterior vapors and exits through the posterior ones, which creates differences from "ordinary" breathing. By the way, in the same insect, with an increased content of carbon dioxide, air in can begin to move in the opposite direction: it can be drawn in through the abdominal and out through.

How do aquatic insects breathe?

In insects that live in water, breathing is carried out in two ways. It depends on what structure they have.

Many of the aquatic organisms are closed, in which they do not function. It is closed, and there are no “exits” to the outside in it. Breathing is done with - outgrowths of the body, which enter and branch abundantly. Thin tracheoles come so close to the surface that oxygen begins to diffuse through them. This allows some insects living in the water (and caddisflies, stoneflies, mayflies, dragonflies) to carry out gas exchange. Upon their transition to a terrestrial existence (turning into), they are reduced, and from a closed one it turns into an open one.

In other cases, the respiration of aquatic insects is carried out by atmospheric air. Such insects have an open. They take in air through, floating to the surface, and then sink under water until it is used up. In this regard, they have two structural features:

Other features are also possible. For example, in a swimming beetle, they are located at the posterior end of the body. When she needs to "take a breath", she swims to the surface, takes a vertical position "upside down" and exposes the part where they are located.

The breathing of adult swimmers is interesting. They have developed, from the sides bending down and inward, towards the body. As a result, when floating to the surface with folded elytra, the beetle captures an air bubble that enters the subelytral space. They open there. Thus, the swimmer renews oxygen supplies. A swimmer of the genus Dyliscus can stay under water for 8 minutes between ascents, Hyphidrus for about 14 minutes, Hydroporus for up to half an hour. After the first frost under the ice, the beetles also retain their viability. They find air bubbles underwater and swim above them in order to "pick" them under.

In aquatic, the storage of air occurs between the hairs located on the abdominal part of the body. They are not wetted, so a supply of air is formed between them. When an insect swims under water, its ventral part appears silvery due to the air cushion.

In aquatic insects breathing atmospheric air, those small reserves of oxygen that they capture from the surface should be used up very quickly, but this does not happen. Why? The fact is that oxygen diffuses from the water into the air bubbles, and carbon dioxide partially escapes from them into the water. Thus, taking air under water, the insect receives a supply of oxygen, which replenishes itself for some time. The process is highly dependent on temperature. For example, the Plea bug can live in boiled water for 5-6 hours at warm temperatures and 3 days at cold temperatures.

In all of these cases, skin respiration occurs. Insects breathe the entire surface of the body (the first instars