The structure and work of the human heart is a huge mechanism in which a lot of various processes are involved, the failure of at least one of which will lead to a complete stoppage of the entire machine.
Without ATP (nucleotide, which plays a very important role in the metabolism and energy in the body and is known as a universal source of energy for absolutely all biochemical processes). If the cell ceases to produce ATP, then this is equivalent to stopping the generators at the power plant.
Lysosomes purify the cell from unnecessary metabolic products, and also regulate a number of important intracellular processes aimed at restoring cell particles destroyed during its functioning.
Finally, in the cardiac cage there is a complex system of intracellular tubules (endoplasmic reticulum). In addition, these ducts play an important role in the process of reducing myofibrils. It is on the membranes of these tubes that the two processes (conjugation) of two processes-excitation and contraction-are made, that is, an exciting (command) impulse causes shortening of myofibrils here, and the cardiac cell begins to perform work.
If, due to any circumstances, the atria and ventricles of the heart contract simultaneously, then a very serious pathological condition, known as occlusion of the atria, may occur. The fact is that the muscle mass of the ventricles is much larger than the muscle mass of the atria, in other words – the musculature of the ventricles is stronger than the musculature of the atria. If all parts of the heart become agitated and contract simultaneously, then the atria will not be able to push blood into the ventricles, the hemodynamic wave will go in the opposite direction – to the pulmonary and hollow veins, this will severely disturb hemodynamics and can lead to serious circulatory disorders, fainting, more or less prolonged loss of consciousness, etc. But in the norm this does not arise, since in the activity of the heart departments there is a very strict sequence.
For full sealing on each leaf, in its middle, there are thickenings – nodules. When these three nodules lie close to each other, they will not allow the blood to open the valves in the place of their least resistance, that is, at the point of closure. These nodules protect the valves of the aorta and pulmonary artery from eversion under blood pressure.
Cells of the heart conductor system contain much less myofibrils. They have much more glycogen (energy reserve), and they are more resistant to some adverse effects; for example, to a lack of oxygen than the rest of the heart muscle tissue. But especially large differences in them are revealed in the study of their ability to generate electrical potentials.
If we introduce into the cell the so-called working myocardium, that is, into a cell not belonging to the conductor system, the thinnest microelectrode and record with its help the electrical activity of this cell, and to irritate it by another microelectrode by supplying a weak electric current, then we register the first electrode curve. When the electric charge of the cell membrane during a slow diastolic depolarization reaches a certain level, this fiber itself (without any external stimulus) is excited and an action potential arises. Hence, a smooth feature of the conductive tissue of the heart is its ability to spontaneous (that is, occurring without any external influences) generation of the action potential.