WHAT IS CLOSED CIRCULATION? - ANATOMY AND PHYSIOLOGY - 2024

The closed circulation is a system which carries blood through the body of an organism using a system of blood vessels. The heart pumps oxygen-rich blood through arteries throughout the body, and waste-filled, oxygen-deprived blood returns to the heart through the veins.

The circulatory system is one of the transport systems through which nutrients, gases and other molecules are transported within the body of animals. There are two main types of circulatory systems: the open circulatory system and the closed circulatory system.

In the open circulatory system, blood bathes cells directly as opposed to the closed circulatory system in which blood travels through vessels. Since blood in an open circulatory system is not confined to vessels, blood and interstitial fluid have no distinction.

In contrast, blood and interstitial fluid do not mix in a closed circulatory system. A closed circulatory system is made up of the heart that pumps blood to vessels to reach tissues and organs. Gas exchange in the bloodstream occurs between the smallest vessels (capillaries) and tissues.

In a closed circulatory system, blood passes through different blood vessels to reach different organs. In this set, there is a pulmonary circulation and a systemic circulation.

Blood also moves due to a difference in pressure within the blood vessels. This system is ideal for larger animals to supply adequate blood to the extremities.

The closed vascular system is a highly developed system due to:

1. Organisms have a thick wall to prevent the evaporation of water, so the exchange of materials between the cells of the body and the environment by diffusion is not possible.
2. Organisms have a higher metabolic rate and need a greater supply of nutrients and oxygen. They also need faster removal of waste and carbon dioxide.
3. External temperature changes.

Examples of animals with a closed circulatory system are annelids and vertebrates (including humans). Humans have a cardiovascular system made up of the heart and blood vessels that circulate blood throughout the body and another system for the circulation of lymph called the lymphatic system.

Advantages of the closed circulatory system

It is efficient in delivering oxygen throughout an organism

This type of system offers large capacity for oxygen delivery. This involves ultrafiltration of the blood, pulmonary circulation, and systemic circulation. Deoxygenated blood is transported from the heart to the lungs to be oxygenated, which is known as pulmonary circulation.

The oxygenated blood is then transported to the rest of the organs, which is known as systemic circulation. After the blood reaches the tissues through the capillaries, it is returned to the heart through the veins, with the blood pressure in the venous system lower compared to that in the arterial system.

Provides more power in the form of pressure

Compared with the open circulatory system, the closed circulatory system works with a much higher blood pressure.

Since oxygen-containing blood can reach the extremities of the body at a much faster rate than with an open circulatory system, humans, as well as other organisms with the closed system, can metabolize much faster, leading to faster movements, to digestion and elimination of waste.

Apart from this, it also allows for better and efficient distribution of antibodies, making immune responses much stronger and making the body more powerful in fighting infections.

Has a lymphatic system that works separately

In this system, the lymphatic system works separately. The blood is responsible for the transport of gases (oxygen and carbon dioxide), the cells defend the body by regulating the balance of electrolytes and fluids, the balance of acid and base, and body temperature.

It also protects the body from infection and blood loss through clotting. Meanwhile, the lymphatic system is responsible for cleaning the cellular environment by offering a way to absorb fat and fat-soluble vitamins into the bloodstream.

It also helps to return tissue fluids and proteins to the blood and is responsible for the body's defense against disease.

Disadvantages of the closed circulatory system

It is more complex than the open circulatory system

Humans, vertebrates, and the largest and most active animals have a closed circulatory system. Compared with the open circulatory system, the closed circulatory system is much more complex since it includes two main processes: pulmonary and systemic circulation.

While the pulmonary circulation carries deoxygenated blood through the lungs to obtain oxygen, the systemic circulation distributes this oxygenated blood throughout the body. To direct this blood to all organs and tissues, it uses a network of arteries and veins.

The closed circulatory system works with the blood that remains in the vessels and is transported to all the extremities of the body at high pressures and fast speed. The open circulatory system is simpler.

In this, the heart pumps blood into open chambers, with the blood vessels carrying the blood at low pressure throughout the body, and then bathes all organs and tissues with blood.

Also, it does not use the main veins and arteries to increase blood pressure. Organisms with an open circulatory system, such as spiders, insects, mollusks, and shrimp, usually have a lot of blood, yet they have low blood pressure.

Requires more energy for blood distribution

Compared with the open circulatory system, the closed circulation system requires more energy for the distribution of blood. That is why it is said to be naturally designed for animals that have a fast metabolism and larger bodies.

This is also true considering the fact that oxygenated blood needs a large number of networks to travel to the extremities of the body. A lot of organisms on this planet need a circulatory system in order to distribute nutrients throughout your body in an efficient matter and survive.

It is important to consider that the two types of circulatory systems have their own sets of advantages and disadvantages. Although the closed circulatory system allows for faster distribution and is more advanced, it is not suitable for all species. In reality this system comes down to where it is most efficient.

References

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