1. How big is your heart?

First of all, the shape of the heart is completely different from the shape of the heart. It is more like a peach, similar in size to an adult’s fist, and weighs between 230 and 280g.

2. Where does the heart grow?

Most people have a heart on the left, but some people have a heart on the right. The normal heart is located in the chest cavity, above the diaphragm, about 2/3 on the left side of the centre line, 1/3 on the right side of the centre line, and the tip of the heart points to the left front and below. However, some people’s heart grows in the centre, and a very few people’s heart is mostly on the right side, and the tip of the heart points to the front and lower right, that is, the right heart. The right heart is generally a congenital abnormal position, with an incidence rate of about 0.1% of all newborns, but if it is not combined with other cardiovascular deformities, it can still live and work like a normal person.

3. The heart is a pump, and it is a muscle pump.

The blood pumping function of the heart is actually completed by the precise cooperation of the left and right blood pumps. The left and right blood pumps are composed of two parts: the upper part is the atrium and the lower part is the ventricle. There is a thin muscle diaphragm between the left and right ventricles, and a thick muscle septum between the left and right ventricles. Under normal circumstances, the atrial septum and ventricular septum are completely closed, but the lateral atrium and the ventricle will be connected through the atrioventricular valve to ensure the one-way flow of blood.

4. The heart is like a “four-bedroom” structure

The human heart has two atriums and two ventricles, but it is not suitable for all animals. Like humans, mammals, birds, and reptiles also have two atriums and two ventricles, but reptiles are not completely separated from each other; while amphibians have only two atrium and one ventricle; fish have only one atrium and one ventricle.

5. When did the first heartbeat start?

The first time in your life’s heartbeat began earlier than you can imagine. Studies have shown that the first heartbeat of a person may occur as early as around the 16th day of a woman’s fertilised pregnancy. The heartbeat in the mother’s stomach is often said to be the “fetal heart rate”. The normal foetal heart rate is much faster than the adult’s resting heart rate, which is 120 to 160 beats per minute.

6. You may be lazy, but your heart is very self-disciplined.

The heart is an extremely self-disciplined and busy organ. It has its own power system, which comes from the line beating and performs the function of pumping blood. In 80 years or more, the heart beats 60 to 100 times per minute, about 100,000 times a day, and the rhythm is very uniform. Even in the state of exercise (such as walking, running, etc.), the heart rate changes are very “smooth”. To summarise one word is “stability”.

7. How many times do you circle the earth? How long are people’s blood vessels?

The heart transports 5 litres of blood per minute, and the arteries and veins through which the blood flow are about 96,600 kilometres long, which is about two and a half weeks of the earth.

8. Whose heart rate is faster than one?

Young people are faster than the elderly, women are faster than men of the same age, and people who exercise less are faster than those who often exercise.

9. Keep warm. Body temperature will also affect your heartbeat.

Temperature affects the heart rate. Generally, every time the body temperature rises by 1°C, the heart rate will accelerate by 10 times per minute; on the contrary, when the body temperature decreases, the heart rate will also slow down.

10. Where does the heartbeat come from every day?

The heartbeat we usually hear does not come from the heart muscle or blood flow, but from the sound made when the heart valve is opened and closed (similar to applause).

11. Can the heart beat when it leaves the body?

The heart has an independent power system. Even if it leaves the body, it can still beat for a certain period of time.

12. How strong is the heart pressure? Beyond imagination

The systolic pressure produced by the heart can spray blood 9 metres away, which is equivalent to 3 floors high.

13. All organs of the human body can become cancerous, but the heart is difficult.

The clinical incidence of heart tumours is extremely low. The incidence of primary heart tumours is only about 0.02%, and it is mainly benign tumours such as myxoma.

14. Long-lived cardiomyocytes are difficult to recover once they are “sad”

The regeneration ability of mature cardiomyocytes is very low, and it can also be said that they live a long life. But this does not mean that cardiomyocytes cannot divide and increase in value. The study found that at the age of 25, myocardial cells would renew themselves at a rate of 1% per year, but by the age of 75, there was only 0.45% left. This also tells us that the self-renewal potential of the heart is limited, and it is difficult to recover after myocardial infarction or myocardial cell damage.

15. It’s heartbreaking. The heart is really “broken”.

“My heart is broken” is sometimes not just an emotional expression, but also clinically “heartbreak”. When people experience major external events such as lovelornness and car accidents, abnormal contraction and disfunction of the myocardium will occur, causing dyspnoea, suffocation, chest pain and other symptoms similar to heart attacks, that is, “heartbreak syndrome”.