Human Heart

After running, when you stop, do you hear that pumping sound? Yes, you guessed it right. That is your heart pumping very fast. You can feel it when you put your hand to your chest. But what is it pumping? Just like a water pump, pumps water, your heart pumps blood. It pushes blood all over your body.

FUN FACT: Does your heart stop momentarily when you sneeze? It’s false!! It is a common myth, but it’s not true, your heart beats through your ‘aa-choo’!

Our heart, like all other organs, is made up of very strong muscles and is situated a little left to the centre of our chest in an angle, between our lungs. Blood acts as the messenger carrying nutrients and oxygen, along with some waste products from different body parts to our heart, and the other way around. The blood that is sent to the heart flows in veins and it is deoxygenated with very fewer nutrients.

FUN FACT: A human heart weights approximately 450g, which is almost half of a kilogram !!

The heart is divided into two parts, the left and right part, separated by a wall made of cells, so they aren’t connected internally. You must be wondering why. Well, the heart is a complex organ performing a very critical role in our body.

Each of these halves, has two chambers (cavities), the upper cavities are called as right and left atrium(passages) and the lower ones are called as right and left ventricles. So, in total there are 4 chambers which make up our heart.

Now, this is where it gets interesting. The blood comes to the right atrium first. This blood is deoxygenated, meaning that it will have less oxygen and nutrients. Then it goes to the right ventricle through a valve.

Word of the day: VALVE– it is a structure which controls the passage of fluid through it. You must be wondering why would a heart need a valve? It is to make sure that the blood does not go back to the chamber it came from. Did you know that fluid can mean both air and liquid???

From the right atrium, the blood is sent to the place which is extremely rich of oxygen. Yes, you guessed it right, it’s the lungs. Here, the blood gets properly oxygenated, filled with oxygen and nutrients.

After this, the blood ( imagine a well-fed tummy) moves back to the left atrium, and to the left ventricle from there through a valve. Now this blood is sent to all the parts of the body so that our body works like a well-oiled machine.

FUN ACTIVITY: To understand how our heart beats, imagine your hand (clenched fist) as a heart. Every time it opens, it fills up with blood, and when you close it, it pumps blood outwards. 

Before we end, let’s see how much you have learned.


Q 1. The heart is a part of which body system?

a) Digestive System

b) Respiratory System

c) Circulatory System

d) Nervous System

Q 2. A heart has how many ventricles?





Q 3. In a day, how many times does our heart beat?





Q 4. Our arteries carry deoxygenated blood.

a) True

b) False

Q 5. When we run, our body parts need more oxygen, and that is why our heart beats faster.

a) True

b) False

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