How does air get into an insect's body?

Encounters with nature 2, textbook

Insects Insects have a belly marrow The insects' nervous system, which is relatively simple, consists of the brain located in the head, which is connected to the compound eyes. Two nerve cords pull away from the brain towards the abdomen and backwards. They are connected to one another via thickenings in the segments, the nerve nodes, like a rope ladder. This so-called rope ladder nervous system or abdominal cord is typical of insects. Insects have an open circulatory system In the previous year you only got to know animals that, like us, have red blood that is pumped through the body in blood vessels. Like all insects, the cockchafer does not have red blood, but a colorless liquid, the so-called hemolymph. It flows freely through the whole body, washing around the organs and supplying them with nutrients. A tubular heart keeps the hemolymph moving. The liquid is sucked in from the abdomen through small, lateral openings in the heart and pumped towards the head through a subsequent blood vessel. Since this dorsal vessel is open at the front, the hemolymph gets into the body cavity, flows backwards and is sucked back from there by the tubular heart. If the blood or the hemolymph circulates openly in the body cavity, it is called an open circuit. In a closed circuit, the blood constantly flows in a network of vessels. The respiratory organs of insects are called trachea mammals, birds and reptiles breathe with their lungs. The oxygen contained in the air enters the blood through the alveoli, where it is absorbed by the red blood cells and distributed throughout the body with the bloodstream. Insects like the cockchafer do not need red blood cells to transport oxygen. Your respiratory organs, the trachea, bring the air directly to the organs. Trachea (Fig. 9) are fine windpipes that run through the entire body of the insect. In many insects they are clearly visible in the wings, for example in the cockchafer in the hind wings. The entrances to the trachea are on the side of the abdomen. Oxygen-rich air flows in from the outside through these breathing openings, or air that is laden with carbon dioxide flows outside. The gas exchange can be increased by raising and lowering the abdomen. The intestine is divided into several sections. The intestinal canal is divided into fore, middle and rectum. The foregut consists of the esophagus, which widens before the transition to the next section of the intestine to form what is known as the goiter. In the midgut we differentiate between the glandular stomach and the glandular stomach. The food is further chopped up in the chewing stomach. The final digestion takes place in the glandular stomach. Indigestible food is passed through the rectum. The excretory organ flows into the rectum. It consists of thin tubes that absorb excretions from the hemolymph and release them into the rectum. Hemolymph haima (Greek) = blood, lympha (Latin) = spring water 1. Why do humans need red blood cells, but insects don't? 2. What is the difference between blood and hemolymph? 3. Describe the vertebrate excretory organs. It's your turn! 9 Trachea system (scheme) 10 The tracheas in the wings of the honey bee are easy to recognize. Breathing holes 25 For testing purposes only - property of the publisher รถbv

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