Did you know that early in embryonic life, the heart and brain are practically glued together? I have prepared for you a list of 22 interesting things about your heart:
1. The heart does not hurt. It has no actual pain receptors. The pain is felt on the periphery of the body and is called angina (never below the navel; if it’s pain in the lower part, it’s not angina).
2. The best heart rate is between 55 and 65 beats per minute. Then there is the best performance-oxygen consumption ratio.
3. Perfusion in the arteries of the heart (called coronary) takes place in diastole (the pause between two contractions, called systole).
4. There is a “brain” in the heart, where some cells spontaneously emit electrical impulses. They form the sinus node and dictate the entire activity of the heart. Impulses travel through preferential paths, like highways, but also from close to close, from cell to cell.
5. The electrocardiogram records the electrical activity of the heart on the surface of the body. It is still particularly useful in disease detection, monitoring, screening.
6. Heart rate is not fixed, but dynamic. It increases with effort, emotions, and stressful situations and decreases with calmness, rest, and sleep.
7. A physiological bradycardia sets in during sleep. The rate may drop to 40-50 bpm. There is nothing bad (pathological) here.
8. 200 people can describe 200 symptoms and all of them can be angina. Pain, discomfort, clawing, stabbing in the chest, arms, hands, neck, jaw, teeth, back, abdomen (not below the navel) – all can be angina.
9. Blood does not flow continuously through the arteries at the same speed; the flow is rather laminar, dictated by the systole of the heart, but also by the particularities of the blood vessel. We have over 100,000 kilometers of vascular networks in the body!
10. The heart does not generate love. It does not secrete any substance related to this cocktail of feelings. The brain takes care of that. But the heart changes in love and can suffer without it. See thebroken heart syndrome section below.
11. The main function is a pump, but there is also a hormonal function (certain peptides that can dilate and stimulate diuresis – they are synthesized under the effect of pressure on the ventricles).
12. The flow of blood through the heart is well calculated, in one direction. Four complex valve apparatuses do this. Between the left atrium and the left ventricle is the mitral valve. Between the right atrium and the right ventricle is the tricuspid valve. Between the LV and the aorta, there is the aortic valve, and between the RV and the pulmonary artery, there is the pulmonary valve.
13. The heart is not placed on the left side, but on the center of the chest. The apex (top) bulges to the left. That apex hits the chest itself during systole and the impact can be felt – it’s called apex shock.
14. The adult heart is approximately the size of the right fist.
15. There is a broken heart syndrome (broken heart syndrome or tako tsubo) that occurs more often in women who have gone through great suffering (love, human losses). The apex of the heart is ballooning. It is usually reversible. Tako tsubo is an octopus trap used by the Japanese – in this syndrome, the heart changes like the shape of that trap.
16. The heart can compensatoryly enlarge in performance athletes. As a rule, the frequency also decreases, because the volume of expelled blood is increased. There are performance athletes who have 35-40 beats per minute.
17. The heart is under sympathetic and parasympathetic nervous control. These systems dynamically control frequency, among other parameters. The sympathetic nervous system increases the frequency and blood pressure, and the parasympathetic decreases these parameters.
18. The transplanted cord no longer has direct nerve control and usually, the frequency does not oscillate much.
19. Palpitations are the awareness of the heartbeat. Normally, cardiac activity is not felt.
20. The heart is kept healthy by avoiding smoking, being sedentary, correcting obesity, maintaining a balanced mental status, a diet in which the dose of each component is chosen with common sense, exercise, and sufficient rest.
21. The heart starts beating when the embryo is four weeks old. It is the first functional organ of man.
22. The embryonic bud from which the heart appears is at first glued to the one from which the brain develops, both being placed in the cephalic extremity (head) of the embryo. The heart then gradually descends to the level of the chest.
