Question

Mention about briefly the circulatory system of an earthworm?

Answer 1

Hint: The circulatory system of the earthworm is the system by which blood is flowing from the heart to the rest body organs of the earthworms. Earthworms are classified in the phylum Annelida which means ‘little rings’. The body of earthworms is segmented and looks like the various rings are fused.

Complete Answer:
- In this particular question we have to study the circulatory system of earthworms. It is a closed type system. Earthworm (also called Pheretima) has a closed type of blood circulatory system which comprises heart, blood vessels and capillaries. The pumping of the heart takes place in a single direction.
- Blood is supplied by the body with smaller cells to the gut nerve cord and then the body walls. Segments 4, 5and 6 have a blood gland which produces blood cells and haemoglobin which dissolved in the blood plasma. Three major vessels supply the blood to organs inside the earthworm. These vessels are the aortic arches, ventral blood vessels and dorsal blood vessels.
- Earthworm aortic arches are similar to the human heart. There are a total of 5 pairs of aortic arches that have the accountability of pumping blood into the ventral and dorsal blood vessels. Its ventral blood vessels are responsible for the transport of blood to the back part of the earthworm body and its dorsal blood vessels (single and largest blood vessels) are responsible for transport blood to the front part of the earthworm body.
- The colour of blood in earthworms is red because the haemoglobin is dissolved in the blood plasma. The dorsal vessels are the major vessels of the circulatory are single, largest vessels and it contracts rhythmically and the flow of blood is posterior to anterior. Another very important blood vessel is the ventral blood vessels which are located in the ventral region of the gut. These are single and distributed type vessels and the flow of blood is forward to backward.

Note: The blood circulatory system of an earthworm is the closed type circulatory system. This system comprises the three main types of organs: heart, blood vessels, and capillaries. There are two main blood vessels such as dorsal blood vessels and ventral blood vessels.