Oct 21, 2024

Blood circulation

Article on the role and functioning of blood circulation

Welcome to this article dedicated to blood circulation and the crucial role it plays in the human body. You'll discover how this complex system transports oxygen and nutrients and removes waste to keep our organs healthy. Before you begin, test your knowledge with this quick quiz.

Test your knowledge of blood circulation

What is blood circulation?

Circulation is the process by which the heart pumps blood through a network of blood vessels to deliver essential oxygen and nutrients to all cells in the body. This system consists of the heart, arteries, veins, and capillaries. It operates in two main circuits:

Pulmonary circulation : transports deoxygenated blood from the heart to the lungs to recover oxygen.
Systemic circulation : transports oxygenated blood from the lungs to the rest of the body.

Did you know? Every day, your heart pumps approximately 7,000 to 8,000 liters of blood through your body!

Figure 1: Blood vessels in purple. Credit: Hynes Lab, Koch Institute

Why are cardiomyocytes so important?

Blood circulation is vital to keeping every organ and tissue alive. Blood carries oxygen from the lungs to every cell in the body and returns carbon dioxide, a waste product, to the lungs to be expelled during breathing. It also distributes nutrients absorbed by the digestive system and helps eliminate waste through the kidneys and liver.

Arteries are responsible for carrying oxygenated blood from the heart to the rest of the body, while veins return oxygen-deficient blood to the heart to be reoxygenated in the lungs. Capillaries, tiny vessels, play a key role in facilitating the exchange of gases, nutrients, and waste between the blood and cells.

Figure 1: Cardiomyocytes derived from induced pluripotent stem cells, stained for F-actin (magenta) and DNA (gray). Credit: Dr. Outi Paloheimo

How does the heart work?

The heart is a muscular pump that beats approximately 100,000 times a day to pump blood throughout the body. It consists of four chambers: two atria and two ventricles. Deoxygenated blood enters the right atrium and then passes into the right ventricle, which pumps it to the lungs to be oxygenated. Oxygenated blood then returns to the left atrium, passes into the left ventricle, and is pumped throughout the body via the aorta.

Did you know? The left ventricle is the most powerful chamber of the heart because it must pump blood throughout the body, sometimes to distant areas like the tips of the fingers or toes!

What do you think?

Can blood vessels regenerate after injury or disease?

Expert Answer: Yes, blood vessels can regenerate after injury or disease. This process is known as neovascularization, which involves the formation of new vessels from existing ones. However, the ability to regenerate depends on several factors, such as age, general health, and the severity of the injury. Research advances, such as those of Didier Letourneur, are highlighting innovative methods to promote this regeneration. So, the correct answer is "Yes."