The heart is a fist-sized organ that pumps blood throughout your body. It’s the primary organ of your circulatory system.

Your heart contains four main sections (chambers) made of muscle and powered by electrical impulses. Your brain and nervous system direct your heart’s function. Read this article full with Pritish Kumar and get enough knowledge about Human’s Heart.

What does a heart diagram look like?

The inside and outside of your heart contain components that direct blood flow:

Heart looks from inside

Outside view of heart


What is the heart’s function?

Your heart’s main function is to move blood throughout your body. Your heart also:

  • Controls the rhythm and speed of your heart rate.
  • Maintains your blood pressure.

How does your heart work with other organs?

Your heart works with other body systems to control your heart rate and other body functions. The primary systems are:

Nervous system: Your nervous system helps control your heart rate. It sends signals that tell your heart to beat slower during rest and faster during stress.

Endocrine system: Your endocrine system sends out hormones. These hormones tell your blood vessels to constrict or relax, which affects your blood pressure. Hormones from your thyroid gland can also tell your heart to beat faster or slower.


Where is your heart located?

Your heart is located in the front of your chest. It sits slightly behind and to the left of your sternum (breastbone). Your ribcage protects your heart.

What side is your heart on?

Your heart is slightly on the left side of your body. It sits between your right and left lungs. The left lung is slightly smaller to make room for the heart in your left chest.

How big is your heart?

Everyone’s heart is a slightly different size. Generally, adult hearts are about the same size as two clenched fists, and children’s hearts are about the same size as one clenched fist.

How much does your heart weigh?

On average, an adult’s heart weighs about 10 ounces. Your heart may weigh a little more or a little less, depending on your body size and sex.

What are the parts of the heart’s anatomy?

The parts of your heart are like the parts of a house. Your heart has:

  • Walls.
  • Chambers (rooms).
  • Valves (doors).
  • Blood vessels (plumbing).
  • Electrical conduction system (electricity).

Heart walls

Your heart walls are the muscles that contract (squeeze) and relax to send blood throughout your body. A layer of muscular tissue called the septum divides your heart walls into the left and right sides.

Your heart walls have three layers:

  • Endocardium: Inner layer.
  • Myocardium: Muscular middle layer.
  • Epicardium: Protective outer layer.

The epicardium is one layer of your pericardium. The pericardium is a protective sac that covers your entire heart. It produces fluid to lubricate your heart and keep it from rubbing against other organs.

Heart chambers

Your heart is divided into four chambers. You have two chambers on the top (atrium, plural atria) and two on the bottom (ventricles), one on each side of the heart.

Right atrium: Two large veins deliver oxygen-poor blood to your right atrium. The superior vena cava carries blood from your upper body. The inferior vena cava brings blood from the lower body. Then the right atrium pumps the blood to your right ventricle.

Right ventricle: The lower right chamber pumps the oxygen-poor blood to your lungs through the pulmonary artery. The lungs reload blood with oxygen.

Left atrium: After the lungs fill blood with oxygen, the pulmonary veins carry the blood to the left atrium. This upper chamber pumps the blood to your left ventricle.

Left ventricle: The left ventricle is slightly larger than the right. It pumps oxygen-rich blood to the rest of your body.

Heart valves

Your heart valves are like doors between your heart chambers. They open and close to allow blood to flow through.

The atrioventricular (AV) valves open between your upper and lower heart chambers. They include:

  • Tricuspid valve: Door between your right atrium and right ventricle.
  • Mitral valve: Door between your left atrium and left ventricle.

Semilunar (SL) valves open when blood flows out of your ventricles. They include:

Aortic valve: Opens when blood flows out of your left ventricle to your aorta (artery that carries oxygen-rich blood to your body).

Pulmonary valve: Opens when blood flows from your right ventricle to your pulmonary arteries (the only arteries that carry oxygen-poor blood to your lungs).

Blood vessels

Your heart pumps blood through three types of blood vessels:

  • Arteries carry oxygen-rich blood from your heart to your body’s tissues. The exception is your pulmonary arteries, which go to your lungs.
  • Veins carry oxygen-poor blood back to your heart.
  • Capillaries are small blood vessels where your body exchanges oxygen-rich and oxygen-poor blood.

Your heart receives nutrients through a network of coronary arteries. These arteries run along your heart’s surface. They serve the heart itself.

Electrical conduction system

Your heart’s conduction system is like the electrical wiring of a house. It controls the rhythm and pace of your heartbeat. It includes:

  • Sinoatrial (SA) node: Sends the signals that make your heart beat.
  • Atrioventricular (AV) node: Carries electrical signals from your heart’s upper chambers to its lower ones.

Your heart also has a network of electrical bundles and fibers. This network includes:

  • Left bundle branch: Sends electric impulses to your left ventricle.
  • Right bundle branch: Sends electric impulses to your right ventricle.
  • Bundle of His: Sends impulses from your AV node to the Purkinje fibers.
  • Purkinje fibers: Make your heart ventricles contract and pump out blood.

How can I keep my heart healthy?

If you have a condition that affects your heart, follow your healthcare provider’s treatment plan. It’s important to take medications as prescribed.

You can also make lifestyle changes to keep your heart healthy. You may:

  • Achieve and maintain a healthy weight for your sex and age.
  • Drink alcohol in moderation.
  • Eat a heart-healthy diet with plenty of fruits, vegetables and whole grains.
  • Exercise moderately for at least 150 minutes per week.
  • Limit your sodium intake.
  • Manage your stress with healthy strategies like meditation or journaling.
  • Quit smoking and/or using tobacco products and avoid secondhand smoke.