How The Earthworm Breathes

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How The Earthworm Breathes
How The Earthworm Breathes

Video: How The Earthworm Breathes

Video: The Amazing World Of Earthworms In The UK - Springwatch - BBC Two 2022, December

The annelids, which include earthworms, do not have special organs responsible for respiration. Gas exchange occurs with them through the diffusion of the whole body, that is, they "breathe through the skin."

How the earthworm breathes
How the earthworm breathes


Step 1

Respiratory organs are not necessary for worms, since the annular structure and cylindrical shape provide an optimal ratio of volume and surface area involved in obtaining oxygen. Considering that worms move a little enough, we can say that such breathing through the skin is quite enough for them.

Step 2

However, worms have a circulatory system, unlike unicellular organisms and some species of insects, hemoglobin is dissolved in the blood of the earthworm, which is carried through the body through the contraction of large vessels when the worm moves. This circulates oxygen throughout the body, helping to maintain diffusion. Large vessels are one vein and one artery; this is how many vessels the worm has (except for the capillaries located under the cuticle).

Step 3

As such, the skin, like mammals, the earthworm, in principle, does not have, there is a very thin cover - the cuticle. Such skin is moistened by epithelial secretions, and due to its minimal thickness allows the worm to breathe. However, such skin is not protected from drying out, because the worms must live in a kind of humid environment in order to protect the skin from drying out. Oxygen is preliminarily dissolved in water, which covers the body of the worm, and only then is absorbed into the blood through the capillaries. If the skin of the worm dries up, it cannot receive oxygen from the environment and dies.

Step 4

Since the earthworm practically does not come to the surface, such a respiratory system turns out to be extremely beneficial for it - it can take oxygen directly from the soil for gas exchange. There is enough oxygen between the particles of the earth to supply them with the worm. During the rain, worms crawl out of the ground to the surface, this is due to the fact that water sticks together the particles of the earth, and there is no air between them. To get the oxygen they need, the worms must rise to the surface.

Step 5

To test the breathing of an earthworm, you can conduct a simple experiment: earth is poured into a jar, several worms are placed on top. After a short time, the worms will bury themselves in the ground, but if you pour water on the ground, they will rise to the surface. All annelids breathe in the same way - with the help of the skin, the entire surface of the body.

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