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What is the Cardiovascular System

What is the Cardiovascular System, and why is it so Important?

15.MAR.2023

Written by Anna Sanniti Medically reviewed by Dr. Zara Fullerton

The cardiovascular system consists of the heart (cardio) and blood vessels such as arteries and veins (vascular). The main function of the cardiovascular system is to move blood around your body and supply your organs and tissues (tissues are groups of similar cells) with oxygen and vital nutrients [1]. In this article, we will talk about the function of the:

  • Heart

  • Arteries and veins

  • Capillaries

  • Coronary vessels

Heart

The heart is a very powerful muscle the size of your closed fist that creates enough force to pump blood around your entire body (It pumps 5 liters of blood every minute!). 

You probably have heard of cardio exercise. This is any physical exercise that aims to increase your heart rate and pump more blood through your vessels and around your body. 

The heart is split into two sides, the right and the left, which are further split into two chambers called atriums and ventricles. Blood flows through the right atrium and the right ventricle, then travels to the lungs to pick up oxygen and drop off carbon dioxide. The oxygenated blood then returns to the left atrium and the left ventricle and is pumped to the rest of the body. ¹

Arteries and veins

Blood vessels, called arteries and veins, are like the motorways and larger roads that connect all the parts of the body so that the blood can deliver oxygen and nutrients and remove waste products. ¹

Arteries carry blood away from the heart, and veins carry blood towards the heart. 

Your body is very clever - blood vessels direct and carry more or less blood to different areas of the body according to its needs. For example, after a large meal, more blood will be delivered to your digestive system.² In cold weather, more blood is sent to keep your internal organs working, which is why you may get cold hands and feet! ³

Capillaries

Capillaries are very small blood vessels that connect the arteries with the veins. They are the small local roads that connect the motorways and main roads together. The main function of the capillaries is to exchange oxygen and nutrients with carbon dioxide and other waste products within the tissues. ¹

Coronary vessels

As the heart is primarily a muscle, it requires its blood supply to provide oxygen and nutrients and to remove waste products. The coronary arteries supply oxygenated and nutrient-rich blood to the muscular tissues of the heart, The blood, now containing waste products, then passes into the coronary veins. Most of this blood will then flow into the right atrium to pick up oxygen again. ¹

The health of our heart is, therefore, dependent on the health of our blood vessels. It is important to ensure that our heart receives the oxygen and nutrients it requires to work optimally.

Let’s recap

  • The cardiovascular system moves blood around your body, supplies your organs and tissues with oxygen and nutrients, and removes waste products such as carbon dioxide. 

  • The heart is a powerful muscle that creates enough force to pump blood around your entire body. 

  • Blood vessels, called arteries and veins, are like the motorways and larger roads that connect all the parts of the body. Arteries carry blood away from the heart, and veins carry blood towards the heart. 

  • Capillaries are very small blood vessels that connect the arteries with the veins. They are the small local roads that connect the motorways and main roads. The exchange of oxygen and nutrients with tissues happens in the capillaries. 

  • The heart contains strong muscle that requires its blood supply and a large network of capillaries. Oxygenated and nutrient-rich blood is supplied by the coronary arteries, and waste products are taken away by the coronary veins.

  • The health of our heart is dependent on many factors including the health of our blood vessels.

Please note that the following is for educational use only and is not a substitute for medical advice. This content cannot diagnose or provide information about treatment. Consult with your healthcare provider if you have any concerns or need specific medical advice relating to any symptoms, conditions, diagnosis, or treatment. Do not delay seeking medical advice and do not disregard professional medical advice based on this content. Your healthcare provider can provide the most suitable guidance based on your situation.

References

1. National Cancer Institute. Seer Training Modules. Cardiovascular. Online: training.seer.cancer.gov

2. National Library of Medicine. The Gastrointestinal Circulation. Online: ncbi.nlm.nih.gov

3. Stephen S Cheung. Responses of the hands and feet to cold exposure. Temperature, 2015;2:1,105-120. Online: tandfonline.com