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How Does the Heart Work?

Manali Oak
The human heart works like a pump that circulates blood throughout the body. Starting to beat as early as 18-21 days after conception, it continues to function throughout one's life. Let's take a closer look at the working of our heart.
The circulatory system enables the movement of nutrients and wastes to and from the cells of our body. It helps in the maintenance of homeostasis. It is composed of blood, the blood vessels, and the heart.
The heart is an involuntary muscle which pumps blood through the arteries and veins thus facilitating blood circulation. It is truly the 'heart' of our circulatory system.

How the Heart Works

If you imagine the heart to be a pump, blood vessels are the pipelines laid out all over the body. This pumping system is responsible for circulating pure blood throughout the body.
After about 21 days following conception, the human heart starts beating at a rate which is nearer to the mother's heart rate. It is still a mystery how blood circulates in the embryo for the first 21 days when the heart has not yet formed.
The heart consists of four chambers - two atria and two ventricles.
The right side of the heart collects deoxygenated blood in the right atrium. Blood flows to the lungs via the right ventricle. In the lungs, the blood is oxygenized. Purified blood is collected in the left atrium. From here, the blood goes into the left ventricle. The left ventricle is responsible for circulating it to all the body parts.

1. Blood in the right atrium enters the right ventricle through the tricuspid valve.

2. It flows to the lungs via the pulmonary artery.
3. Blood travels to the left atrium through the pulmonary vein. The vein brings in the oxygen-rich blood to the left atrium.

4. It then has to flow through the mitral valve to reach the left ventricle.
5. Through the aortic semilunar valve, blood is pumped to the aorta. The aorta forks and the blood takes its path to travel to the organs of the upper and the lower body.

6. The arteries, the arterioles, and the capillaries form a network for the flow of blood to each and every cell of our body.
7. Some blood goes to the kidneys. They filter out the wastes from blood before the blood treads on its way back to the heart.

8. The venules that fuse to form the veins and then the inferior and superior venae cavae are carriers of deoxygenated blood back to the right atrium.
9. The atria and the ventricles alternately contract and relax to pump the blood to our body. When the ventricles contract, blood can flow backwards into the atria. But the mitral and tricuspid valves prevent this from happening by closing when the ventricles are full.
How does the heart work without ceasing? From where does it derive nutrition?
Blood that the heart pumps does not supply it with oxygen. Coronary arteries are special blood vessels which are attached to the heart from outside. They render oxygen and nutrients to the heart. The right coronary artery supplies blood to the right ventricle while the left one services the rest of the heart.
The sinoatrial node in the right atrium of the heart generates an electrical impulse at regular intervals. It causes the atria to contract and pump blood into the ventricles.
How does the heart beat?
The impulse reaches the atrioventricular node from where it reaches the ventricles through the atrioventricular bundle. Ventricles contract to pump blood to the arteries. The heart then relaxes for a small period after which it starts beating again.
The electrical system of the heart makes its beating possible. When an individual is at rest, the heart beats at the rate of 70-100 beats per minute. It makes a lub-dub sound with each beat.
Our heart is the most wonderful organs of the human body. It gives life to every cell of the body by feeding it with oxygenated and nutrition-rich blood. Now that you know how the heart works, don't you think it is important to provide it with a healthy environment to work in? And that's a reason we should follow a healthy lifestyle and have a positive mind.