How do insects and other invertebrates exchange gases without lungs?

Insects and other invertebrates exchange gases through a system of internal tubes called tracheae.

Tracheae are a network of tubes that branch throughout the insect's body, delivering oxygen directly to the cells and removing carbon dioxide. The tubes are supported by chitin, a tough, flexible material that allows them to bend and flex with the insect's movements.

Insects and other invertebrates do not have lungs, so they rely on the diffusion of gases through their tracheal system. The tracheae are connected to the outside environment through small openings called spiracles, which can be opened and closed to regulate gas exchange.

The rate of gas exchange in insects is influenced by a number of factors, including temperature, humidity, and the insect's metabolic rate. Insects that are more active or have a higher metabolic rate require more oxygen and produce more carbon dioxide, so they need to exchange gases more rapidly.

In some insects, such as grasshoppers and cockroaches, the tracheal system is supplemented by air sacs that help to increase the efficiency of gas exchange. These air sacs can store and release air, allowing the insect to breathe more efficiently during periods of high activity.

Overall, the tracheal system is a highly efficient way for insects and other invertebrates to exchange gases, allowing them to survive in a wide range of environments and perform a variety of activities.

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