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Single Circulation

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Single Circulation: An Overview

Do you know what are gills used for? Are gills only present in fish or do some other organisms have gills? Gills are used for respiration and they are present in most aquatic organisms for breathing. Gills are also used in single circulation and serve all fish. Blood only passes through the heart once in a single circulatory system, completing a full circuit through the body of the fish. The exchange of gases occurs in the gills, where the blood goes from the heart (carbon dioxide is released and oxygen is absorbed). To know more about single circulation, continue reading this article!!

What is Single Circulation?

Fishes have a single circulatory system. In the hearts of fish, there are two chambers: an atrium and a ventricle. Deoxygenated blood from the tissues is pumped to the gills for purification, where it is then returned to the heart to be given to the various bodily tissues with oxygen. Blood that has been deoxygenated returns to the heart from tissues. As a result, solitary circulation refers to the flow of blood along a single circulatory channel. Single circulation is exhibited by many aquatic animals such as all fishes, exocomets, hippocampus, etc.

Single Circulation in Fishes

A single circulatory system serves all fish. Blood only passes through the heart once in a single circulatory system, completing a full circuit through the body of the fish. The exchange of gases occurs in the gills, where the blood goes from the heart (carbon dioxide is released and oxygen is absorbed). The body's numerous organs receive oxygenated blood from the gills, which then returns to the heart via these organs. In single circulation, blood flows through the heart only once.


Single Circulation


Single Circulation

Main Features of Single Circulation

The main features of single circulation are explained below.

  • In single circulation, blood only travels once to the heart for every circuit of the body.

  • A single circulatory system is present only in those animals who have two-chambered or three-chambered hearts.

  • Singles circulatory system present in aquatic organisms.

  • In single circulation, only deoxygenated blood goes to the heart.

Differences Between Single Circulation and Double Circulation

Single Circulation

Double Circulation

An atrium and a ventricle are the two chambers of the human heart.

The heart has two atria and two ventricles and is four-chambered.

To complete the circuit, blood only passes through the heart once.

To complete the whole circuit, blood passes through the heart twice.

Blood does not return to the heart after being oxygenated in the gills; instead, it travels straight to body tissues.

Following oxygenation in the lungs, blood returns to the heart where it is then circulated throughout the body.

The heart merely moves deoxygenated venous blood.

The heart pumps both oxygenated and deoxygenated blood via it.

Blood flows at low pressure and is less effective because of this mechanism.

The system is more effective, and the blood flows under strong pressure.

One route is used for blood flow.

Pulmonary circulation and systemic circulation are the two routes through which blood moves.

Happens in fish.

Occurs in mammals and birds.

Single- and Double-Circulation Flow Diagrams


Single and Double Circulation Flow Diagram


Single and Double Circulation Flow Diagram

Interesting Facts

  • About 100,000 km is the length of the circulatory system.

  • The RBCs have a size of 8 microns.

  • Heart rate is slower in larger mammals.

  • Outside of the body, the heart may beat for three to five minutes.

  • Blood comes in various red shades.

  • About 2.5 billion heartbeats have been recorded worldwide.

Important Questions

1. Do arteries carry only oxygenated blood?

Ans: Yes, all arteries carry oxygenated blood, but there is one exception: the pulmonary artery is the only artery that carries deoxygenated blood.

2. Write the names of organisms exhibiting single circulation?

Ans: Single circulation occurs in fishes, reptiles, and other organisms.

3. Is single circulation open or closed?

Ans: Single circulation is a closed type of circulation.

Practice Questions

  1. Do all veins carry deoxygenated blood?

  2. Why is the double circulatory system better than the single circulatory system?

  3. What is single closed circulation?

Conclusion

When the heart pumps blood to the gills for oxygenation, the blood then circulates through the rest of the body before returning to the heart. This process is known as single circulation. It is well known that some animals, like fish, have a single circulatory system. Additionally, they have two chambers in their hearts rather than the usual one atrium and one ventricle. As a result, solitary circulation has a substantial drawback since it delivers oxygen slowly, which slows down metabolism. In the twofold circulatory system seen through humans, blood circulates in two separate circuits.

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FAQs on Single Circulation

1. What is meant by systemic circulation?

Aorta, arteries, arterioles, veins, venules, and vena cava make up the systemic circulation, which transports oxygenated blood from the heart to various parts of the body and deoxygenated blood back to the heart, respectively. The left ventricle's oxygenated blood travels to the aorta, where it travels to numerous tissues through arteries and arterioles. Through venules, veins, and the vena cava, deoxygenated blood from tissues returns to the right atrium. Systemic circulation assists in delivering nutrients and oxygen to tissues while also removing waste materials such as carbon dioxide for excretion.

2. Describe pulmonary circulation.

Pulmonary circulation is the name of a route in which the pulmonary arteries and veins transport deoxygenated blood from the heart to the lungs and oxygenated blood back to the heart, respectively. The deoxygenated blood from the right ventricle does so after passing via the pulmonary artery and into the lungs for purification. Through the pulmonary vein, the left atrium receives its supply of oxygenated blood supplied by the lungs. Pulmonary circulation is the name of this route.

3. What is the purpose of the human circulatory system?

The body receives oxygen, nutrients, and metabolic waste from the blood as it is pumped through the blood arteries by the heart. The blood is then pushed to the lungs to exhale carbon dioxide and absorb additional oxygen after returning to the heart. The cycle is repeated as the blood returns to the heart and is pumped back out to the body. The circulation may be divided into two categories: deoxygenated blood from the heart travels via the lungs through pulmonary circulation, where it is oxygenated and allowed to exhale carbon dioxide.


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