What is a heart? Let's talk about this little engine in detail!

Have you ever wondered where that constant 'dug-dug' sound coming from inside your chest comes from, and what's causing it? It's our heart , a small but very powerful engine-like organ that gives life to our bodies. Today, we'll talk about this amazing organ, how it works, the diseases it causes, and what we can do to keep it healthy.

What exactly is a heart?

Simply put, your heart is a small, but very important organ, about the size of your fist. It's like the main blood pump in our body. It pumps blood throughout our body. This amazing machine is made up of muscles and tissues.

Your heart has four main chambers, like the rooms in a house. Blood enters these chambers and stays there for a while before it is pumped out to other parts of the body. The heart beats with electrical impulses. These impulses move the blood through these chambers. Your brain and nervous system control the heart’s function.

So, what really happens in the heart?

The main function of the heart is to pump blood throughout the body . This blood supplies all the cells in our body with the oxygen and nutrients they need. It also carries away waste products, such as carbon dioxide, that are produced by the cells and delivers them to other organs where they can be eliminated.

In addition, your heart does other things:

• It controls the rate and rhythm of your heartbeat.
• It helps keep your blood pressure at the right level.

The heart doesn't do these things alone. It works in conjunction with other systems:

• Nervous System: The nervous system helps control your heart rate. It sends signals to slow down your heart rate when you're sleeping and speed it up when you're stressed. Just think about how fast your heart beats before you take an exam!
• Endocrine System : This system secretes hormones . These hormones tell your blood vessels to constrict or dilate. This affects your blood pressure. For example, hormones from your thyroid gland can affect how fast or slow your heart beats.

What are the parts of the heart? It's like a house!

We can imagine the parts of the heart like the parts of a big house. Take a look at this description:

• Walls: Like the walls of a house.
• Chambers: Can be thought of as rooms.
• Valves: Like doors to rooms, they can open and close.
• Blood vessels : Like the water pipe system in a house.
• Electrical conduction system: Like the electrical wiring system that supplies electricity to a home.

Heart walls

The walls of your heart are made up of muscles that contract and expand to help pump blood throughout your body. The walls of the heart are divided into right and left sides by a muscular tissue called a septum .

There are three layers in the heart wall:

• Endocardium: The innermost layer.
• Myocardium: The muscular middle layer. This is what primarily contributes to the beating of the heart.
• Epicardium: The protective outermost layer.

This epicardium is one layer of your pericardium . The pericardium is a protective sac that surrounds your entire heart. It produces fluid to lubricate the heart and prevent it from colliding with other organs.

Heart chambers

Your heart has four separate chambers, like four rooms. There are two upper chambers (atria) and two lower chambers (ventricles), on the right and left sides of the heart.

• Right atrium: Two large veins bring oxygen-poor blood into the right atrium. The superior vena cava brings blood from the upper parts of the body. The inferior vena cava brings blood from the lower parts of the body. The right atrium then pumps this blood into the right ventricle.
• Right ventricle: This lower right chamber sends oxygen-poor blood to the lungs via the pulmonary artery . The lungs then re-oxygenate the blood.
• Left atrium: After the blood is oxygenated by the lungs, the pulmonary veins bring oxygen-rich blood to the left atrium. This upper chamber pumps the blood to the left ventricle.
• Left ventricle: The left ventricle is slightly larger than the right ventricle. This is because it pumps oxygen-rich blood throughout the body. So it requires a little more force.

Heart valves

Your heart valves are like doors between the chambers of your heart. They open and close to let blood flow. They also stop blood from flowing in the wrong direction. Isn't that amazing?

Atrioventricular (AV) valves

These valves open between the upper and lower chambers of your heart. They are:

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

Semilunar (SL) valves

These valves open when blood flows out of your veins. They are:

• Aortic valve: Opens as blood flows from your left ventricle into the aorta (the main artery that carries oxygen-rich blood to the body).
• Pulmonary valve: Opens when blood flows from your right ventricle into the pulmonary arteries (the only type of artery that carries oxygen-poor blood to the lungs).

Blood vessels

Your heart pumps blood through three main types of blood vessels:

• Arteries: These carry oxygen-rich blood from the heart to the body's tissues. However, your pulmonary arteries are different, carrying less oxygen-rich blood to the lungs.
• Veins: These bring oxygen-depleted blood back to the heart.
• Capillaries: These are very fine blood vessels. Oxygen-rich blood and oxygen-poor blood exchange through these capillaries.

Electrical conduction system – the 'current' in the heart

The heart's conduction system is like the electrical wiring in a house. It controls the rhythm and speed of your heartbeat. Signals start at the top of the heart and travel down. This conduction system includes:

• Sinoatrial (SA) node: This is where the signals that cause the heart to beat are generated. This is also called the heart's 'natural pacemaker'.
• Atrioventricular (AV) node: Conducts electrical signals from the upper chambers of the heart to the lower chambers.
• Bundle of His, Left and Right bundle branches, and Purkinje fibers: These are what make your heart cells contract and pump blood out.

What are the common diseases that affect the heart?

Heart disease is one of the most common medical conditions. In fact, in some countries, it is the leading cause of death.

Here are some common diseases that can affect your heart:

• Arrhythmia: A heart rate that is too fast, too slow, or irregular.
• Cardiomyopathy : Abnormal thickening, enlargement, or stiffness of the heart muscle.
• Congestive heart failure: The heart becomes so stiff or weak that it cannot pump blood properly.
• Coronary artery disease: Fatty deposits (plaque buildup) inside the coronary arteries, narrowing them.
• Heart attack / Myocardial infarction: A sudden blockage of a coronary artery, depriving a portion of the heart muscle of oxygen.
• Heart valve disease: A heart valve that does not work properly.
• High blood pressure: Your blood pushes hard against the walls of your arteries.
• High cholesterol: An increase in the amount of fats in your blood.

How to keep your heart healthy?

If you have a heart condition, it's important to follow your doctor's treatment plan exactly . There are also several lifestyle changes you can make to keep your heart healthy.