An Overview of the Circulatory System for Kids


Every time our heart beats, it sends blood throughout the body. Blood carries nutrients and oxygen to our organs, and our organs need nutrients and oxygen even second to survive.

Every day your body sends about 2,000 gallons of blood through your blood vessels. Your blood vessels connect your heart to every part of your body.

The circulatory system serves the purpose of carrying the nutrients and oxygen that your body wants where they are needed. It also carries waste products and unwanted chemicals out of the body.

The Heart

The heart is the most important organ in the circulatory system. It is a pump that pushes blood to every part of the body.

Your heart beats around 100,000 times per day, and will beat nearly 3 billion times in your life. When you are asleep your heart does not need to work as hard, so your heart slows down and pumps blood less often.

If you begin exercising or running your heart will speed up and pump more blood. This is because your body needs more oxygen and nutrients when you are exercising.

The heart is made up of 4 different chambers which have muscular walls surrounding them. The heart pumps blood through a vast system of blood vessels.

The Blood Vessels

Arteries – These carry blood away from the heart and are filled with blood that is carrying oxygen.

Arterioles – These are smaller arteries which are not as flexible.

Capillaries – These are very tiny vessels that connect arteries to veins and allow nutrients to reach every part of your body. They also carry waste products out of every part of the body. The capillaries are where the arteries meet the veins.

Veins – These carry blood back to your heart. They are not as strong as arteries, but they have valves that stop your blood from flowing backwards.

The Walls of the Arteries

The arteries are surrounded by a three layer wall, and they are the strongest blood vessels in the body.

The endothelium is a smooth covering inside the artery that allows blood to flow quickly as it moves through the artery.

The media is a layer of muscle and flexible tissue in the middle of the artery wall.

The adventitia is a protective covering on the outside of the artery.

Diseases of the Circulatory System

The circulatory system can have a variety of diseases and problems. These problems affect children, teenagers, and adults alike. There are problems that people are born with, called congenital defects. There are also acquired problems which develop after a person is born.

Coronary Heart Disease

Coronary heart disease is the most common heart problem in adults. The disease is caused by deposits of fat and dead cells that form on the walls of the blood vessels in the heart. These deposits are called plaques and they disrupt the flow of blood to the heart itself.

A clot can also form in a coronary vessel which causes blood flow through that vessel to completely stop. This is a very dangerous emergency, and it can lead to a heart attack.

Heart attacks can result in the heart being damaged if they are not treated quickly. The damage comes from the blood not being able to carry vital oxygen and nutrients to the heart. Heart attacks mostly happen in older adults.

Stroke happens when a blood vessel in the brain ruptures or becomes blocked. Several different things can increase a person's risk for stroke including cigarette smoking, high blood pressure, and  high cholesterol levels.

High Blood Pressure

High blood pressure is a dangerous condition where the heart is working harder than normal to push blood throughout the body. High blood pressure results from a group of factors including smoking, genetics (you have a higher risk of high blood pressure if it runs in your family), having too much salt in the diet, stress, and not eating enough fruits and vegetables. High blood pressure can lead to both stroke and heart attacks.

Keeping Healthy

It is important to develop healthy habits early in life to keep your circulatory system healthy and decrease your risk of heart disease. Regular exercise is recommended for anyone at any age to stay healthy. Eating fruits and vegetables is also critical to keeping your circulatory system healthy. Saturated fats such as the fat found in butter and red meat should also be limited, especially for older adults.

Sometimes healthy eating and a healthy lifestyle is not enough to prevent heart disease or stroke. This is because some individuals are more likely to experience cardiovascular diseases due to genetics (their family’s history of cardiovascular disease).

Thankfully, there are a variety of drugs and treatments that are used to both prevent and treat stroke, heart disease, high blood pressure, and other cardiovascular diseases. Modern medicine comes out with new ways to treat these illnesses every day including new medications, surgical procedures, and preventative treatments (treatments that lower a person's risk of cardiovascular disease).