Blood passes through the heart, lungs, and throughout the body in several stages. After transporting oxygen and nutrients to all organs and tissues, it enters the heart and travels to the lungs to be oxygenated and eliminate waste. It then returns to the heart, which pumps renewed blood through the aorta to nourish the body.
What is the role of blood flow through the heart and body?
Life requires a constant flow of blood through the heart and throughout the body. The heart is a influential muscle that pumps oxygen-rich blood through the body. After leaving the heart, blood travels through numerous blood vessels, accomplishment all parts of the body, from major organs like the brain to the smallest tissues like the tips of the toes. Blood is constantly moving and has two main functions:
- It transports oxygen and nutrients to all organs and tissues.
- It eliminates carbon dioxide and other waste products.
Then, when it is low in oxygen and high in waste products, the blood returns to the heart. It needs to absorb oxygen and remove carbon dioxide so the heart can pump it to the blood vessels in the lungs. The blood is oxygenated and freed of waste products in the lungs before returning to the heart. The heart gratefully accepts this renewed blood and pumps it back to the body.
In addition to its function of transporting oxygen and nutrients, blood also covers infection-fighting cells, called white blood cells. White blood cells play a dangerous role in protecting the body from infection. They circulate throughout the body and react to infections and foreign bodies.
This blood cycle repeats itself over and over again, every second of every day. All of this is due to the heart and blood vessels, which is why together they are known as the circulatory system. The various parts of the circulatory system work together as a first-class service, ensuring that blood is distributed accurately throughout the body.
Blood vessel blockages (such as clots) or other disorders can disrupt this system and lead to health problems. Therefore, it is important to understand how blood flows through the heart and body. You can do everything you can to keep this powerful system, invisible to you in everyday life, in good working order.
Where does blood flow through the heart?
The heart has four chambers, which we can imagine as rooms in our house. Two of them are on the right side of the heart (the right atrium and the right ventricle) and two on the left (the left atrium and the left ventricle). Blood passes through all four chambers, but not all at once.
Like when you get home after a long day at work, blood returns to the heart after traveling throughout your body. It enters the right atrium and then directly into the right ventricle. (It’s like when you walk into the living room and immediately go to the kitchen to grab a bite to eat.)
From the right ventricle, blood can’t immediately reach the two chambers on the left side of the heart. It first has to stop in the lungs to eliminate waste and obtain oxygen. So, it leaves the heart and enters the lungs. (It’s like running to the bathroom to relieve yourself and take a quick shower.)
After leaving the lungs, blood enters the left atrium and, from there, the left ventricle. The left ventricle pumps lifeblood throughout the body, where it circulates before returning to the heart. (You go to your bedroom to get some sleep, and the next day you wake up and go back to work.)
Heart valves
Just like the rooms in your house, the chambers of your heart have doors. These doors, called heart valves, open and close to control blood flow and keep it moving in the right direction. You have four main heart valves:
- The tricuspid valve attaches the right atrium to the right ventricle.
- The pulmonic valve connects the right ventricle to the pulmonary vein (the main artery that carries blood to the lungs).
- The mitral valve joins the left atrium to the left ventricle.
- The aortic regulator connects the left ventricle to the aorta (the main vein that carries blood from the heart to the rest of the body).
What is the order of blood flow through the heart, step by step?
The right and left sides of the heart work together to pump blood throughout the body. Blood circulates through the heart in several stages. These stages occur during a heartbeat, which lasts only one or two seconds.
On the right side
- Oxygen-poor blood from all over the body enters the right atrium over two large veins: the superior vena cava and the mediocre vena cava. These veins drain blood from the greater and lower body, respectively, and deliver it directly to the right atrium.
- The tricuspid valve opens, allowing blood from the right atrium to flow interested in the right ventricle.
- As the right ventricle fills, it contracts, closing the tricuspid valve and opening the pulmonary valve.
- Blood flows through the main pulmonary artery and its branches to the lungs, where it picks up oxygen and releases carbon dioxide.
On the left side
- Oxygenated blood movements from the lungs to the left atrium through large veins called the pulmonary veins. These veins send blood directly to the left atrium.
- The mitral valve opens, sending blood from the left atrium to the left ventricle.
- As the left ventricle fills, it contracts, closing the mitral valve and opening the aortic valve.
- The heart sends blood through the aortic valve into the aorta, from where it flows to the rest of the body.
How much blood does your heart pump?
The heart pumps about 7,600 liters of blood per day. This is enough to fill a swimming pool measuring 2.4 x 3 meters. It beats about 100,000 times a day. Over an average lifespan of almost 79 years, the heart will beat almost 2.9 billion times.
What conditions affect blood flow through the heart?
Several conditions can affect blood flow to the heart. Some of these include:
- Arrhythmia: Irregular heartbeats, such as atrial fibrillation or ventricular fibrillation.
- Congestive heart failure: Damage or weakness of the heart muscle, making it difficult to pump blood to the rest of the body.
- Coronary artery disease (CAD): Hardening and narrowing of the arteries that carry blood to the heart muscle due to plaque buildup.
- Peripheral artery disease (PAD): Hardening and narrowing of the arteries that carry blood to the rest of the body due to plaque buildup.
- Heart attack: Sudden blockage of a coronary artery that prevents oxygen from reaching part of the heart muscle.
- Heart valve disease: A problem with a heart valve. For example, it may be narrowed or leak blood. Structural congenital heart defects: Congenital abnormalities of the heart’s structure, including a bicuspid aortic valve.
- Sudden cardiac arrest: Unexpected loss of heart function due to a problem with the heart’s electrical system.
How does blood flow through the body, step by step?
The heart pumps oxygenated blood through the aortic valve into the aorta. The aorta is the body’s main artery, with numerous branches branching off in different directions to reach different parts of the body. Imagine a tree with a main trunk (the aorta) and many branches (all the arteries that connect to it). The aorta and its branches are responsible for supplying blood to the entire body.
This is what happens when blood enters the aorta:
- Blood flows from the aorta into other arteries that branch directly off it (aortic branches).
- The first branches of the aorta are the coronary arteries, which source blood to the heart muscle.
- Many other arteries branch off from the aorta, passing through the chest and abdomen.
- Finally, the aorta divides (bifurcates) into two terminal branches called iliac arteries. The aorta and iliac arteries form an inverted Y near the navel. Many of the aorta’s branches have their own offshoots, which we can think of as twigs. These arteries run throughout the body.
- Blood from the arteries enters even smaller blood vessels called arterioles.
- The arterioles connect to even smaller vessels called capillaries. Capillaries have very thin walls, allowing oxygen and nutrients to flow to organs and tissues.
- After exchanging oxygen and nutrients for waste products, the capillaries connect to venules. Venules are small blood vessels that connect to veins.
- Veins carry oxygen-poor blood full of waste products back to the heart.
Blood from all veins eventually flows into the superior and inferior vena cava. These two large veins drain blood directly into the right atrium of the heart. The blood then passes through the heart and lungs before returning to the body. Blood flow in the body is a complex and beautiful system. It works 24 hours a day, whether you’re conscious or asleep. This constant blood flow allows you to think, speak, move, and interact with your environment.
What conditions affect blood flow through the body?
Many different circulatory diseases can disrupt normal blood flow in the body. For example, you may develop:
- Weak spots in the walls of your arteries (aneurysms).
- Plaque buildup in your arteries (atherosclerosis).
- Weakened or damaged veins (venous disease).
- Abnormal connections between arteries and veins (arteriovenous fistulas).
Sometimes, you can prevent or at least reduce your risk of developing these diseases. Other times, factors such as heredity (the genes you inherited from your biological parents) and aging play a role, and there’s little you can do about them.
Although you can’t prevent all diseases that affect your blood flow, you can consult a doctor to help you manage any problems that arise and prevent them from getting worse.
How can I improve blood flow in my heart and body?
Here are some tips to maintain healthy blood circulation:
- Achieve and maintain a healthy weight.
- Eat a heart-healthy diet.
- Exercise about 150 minutes a week (i.e., 30 minutes five days a week).
- Limit alcohol consumption.
- Manage stress with healthy methods, such as psychotherapy or meditation.
- Quit smoking and using tobacco products.
Overview
Close your eyes and imagine what you see out the window of an airplane as you prepare to land near a major city. Picture a complex network of roads and highways, connecting and branching at various points. Long lines of cars drive along them, trying to keep up with the traffic and reach their destination. A similar hustle and bustle is constantly happening inside your body, but on a much smaller scale, as blood circulates through your heart and blood vessels.
It’s easy to forget about the small internal processes of your body because you don’t see them every day. However, this constant flow of blood keeps you alive day after day. You may not need to know every detail of how everything works. But knowing the basics can help you discuss any issues that arise, or simply how to stay healthy, with your healthcare professional. Don’t hesitate to contact your healthcare expert if you have questions or concerns about blood flow or any other aspect of your health.