Circulatory System of Earthworm

What Is The Circulatory System Of Earthworms?

The earthworm circulatory system forms a significant part of earthworm biology, as it is responsible for the transportation of food, gases, and waste products in and about the body. An earthworm has a closed type of blood circulatory system, which is more efficient than the open one, for it can regulate blood pressure and blood flow.

Overview Of Circulation

• The earthworm's circulatory system is a closed type.

• It means that the blood flows only through a series of vessels and does not come into direct contact with the body tissues.

• Such an arrangement allows for more efficient transportation of oxygen and nutrients to the various organs and tissues.

Components Of The Circulatory System

• It consists of a few important components: blood vessels, a heart made up of a series of aortic arches, and blood.

• These combined elements ensure the proper flow of materials throughout the earthworm's body.

Blood Vessels

• The two main kinds of blood vessels found in earthworms are the dorsal blood vessels and the ventral blood vessels.

• The former is along the top of the body, picking up blood from the posterior segments.

• On the other hand, the latter runs underneath the alimentary canal, delivering blood to the body segments.

Aortic Arches

• Earthworms have five pairs of aortic arches which function as hearts.

• The primary purpose of these hearts is to push the blood from the dorsal vessel to the ventral vessel, thus maintaining a continuous blood flow without an interrupted circulation system.

Blood Composition

• The blood of the earthworm is red in colour, as it contains haemoglobin in the plasma.

• Haemoglobin plays a vital role in carrying oxygen to various parts of the body for the metabolism of the earthworm's various activities.

Direction Of Blood Flow

• The blood flow is unidirectional in earthworms.

• Blood is pumped from the dorsal vessel into the aortic arches and then into the ventral vessel, and circulation within the body is very effective.

Blood Glands

• Blood glands in segments 4-6 produce blood cells as well as haemoglobin which is essential in the transport of oxygen.

• These glands are indeed crucial in maintaining healthiness as well as functionality of the circulatory system.

Significance Of Circulation

• It transports nutrients, gases, and waste products necessary for metabolic activities and good health of the earthworm.

• It helps in the regulation of the internal environment, ensuring homeostasis of the earthworm.

Comparison With Other Systems

• The earthworm's closed circulatory system is, therefore, much more efficient compared with the open systems found in most invertebrates.

• Coupled with that is its advantage of succeeding in the soil environment, whereby it forms a major component in nutrient cycling and soil health.