It begins to contract when we are embryos of a few millimeters, after just twenty days from conception and when it still has a primitive tube shape. Since then, except for pathological conditions or external forces, as long as we are alive it will not stop beating, until it stops beating we will be alive.
A little more than one beat every second, eighty a minute, a hundred thousand a day, up to more than three billion in a lifetime. We can feel the spread of his contractions in the wrists and neck. During physical work, the frequency and strength of his contractions increases; sometimes it throbs even in the absence of efforts, for the sole influence of a strong emotion, for a fright or for anguish, when we feel we have it in our throat and, in silence, we can perfectly hear the sound of its heartbeat: tum-ta … Tum-tà… tum-tà…
For its being so conditioned by changes in mood, the heart has been considered for millennia the seat of emotions, love and courage. Today we know that it is a sophisticated fibro-muscular mechanical pump, consisting of chambers and valves, connected to large inflow and outflow vessels through which it distributes blood to all parts of the body.
The electrical impulse that causes cardiac contraction arises from the heart itself, independently, from a group of myocardial cells modified with neuro-electrical functions. The frequency and vigor of its contractions, on the other hand, are continuously and finely regulated by the nervous system and the endocrine system, through homeostatic regulation mechanisms, according to the needs of the organism.
Scholars know how the heart in an extremely detailed way, down to the sub-cellular level. Doctors and surgeons are able to repair and replace valves, bypass coronary occlusions, ablate foci of cells that generate arrhythmias.
On the other hand, the emotion of placing the ear on the chest of a loved one is universal. , when the rib cage becomes a sound box at that tireless beat, and one of the most beautiful lines ever written is worth:
how your heart beats fast”. < / p>