Heart as altruist

The heart is the pump that provides life and work of all organs... Heart - reflexogenic area, supporting neurogenic tone of blood vessels. The heart is the source of pulses, tonic brain... But someone has to take care of the heart! Unfair: the heart muscle is working hard, and God forbid to rest at least a minute. Skeletal muscle at full load does still less work than infarction alone. Meanwhile, skeletal muscle is able to work with the maximum load a few seconds, then comes fatigue, although working muscle supports many times growing even after one or two cuts the flow of blood under a rising and a half to two times pressure.
The blood flow through any organ maximum during systole heart when blood pressure maximum. The heart muscle is not entitled even to this because during systole cut it so hard that blood flow there is almost no; the blood flow in the wall of the left ventricle reaches only during diastole, when relaxed infarction not squeezes his vessel where the pressure is on several dozens mm Hg lower than get other organs. Therefore, the blood flow, nourish the heart, relatively modest, and the need heart of oxygen is great: you know, what the appetite of this selfless hard workers. Unwillingly you have him to be satisfied with little and scoop out a small amount of blood is much more oxygen than any other organ. Compared with other bodies heart - spoiled children who are filtered young to be without foam, valuable products waste, a significant part of oxygen is not used, goes to Vienna.
Heavy physical work demands from the heart of increased productivity, high blood pressure, increased heart rate. Ucaschenne reduction - this means increased and more frequent beats, and diastole, precious fraction of a second, when the heart can try oxygen becomes much shorter. Meanwhile need more oxygen.
Trained heart is easier: it is better able to extract oxygen from the blood, but it is larger common, for example in athletes-stayers. But trained heart works with a low frequency. The so-called "beef heart" cool stayers alone reduces not eighty, and not sixty times per minute, and about forty-five times. Diastole is much longer than usual, heart eats better, and throws it at a load more blood: 30 and even 35 l per minute for it and hypertrophies, for the sake of a greater supply blood to consumers. Of course, consumers, i.e. skeletal muscle, too, train, they also learn to recycle more oxygen from the blood, making the life of the heart. So is their mutual education, as a people, than in the worst conditions they had to live, the more attentive attitude to the needs of others...
It turns out that the heart has just sneeze to respond by expanding their vessels. And really going on. Any irritation heart nerves usually leads to an increase of coronary circulation. The exception is the situation when the blood flow is great: then irritation of the vagus nerve brings down the blood flow to the averages. If this is to depict in a form familiar to us "camel", "operating point" for coronary vessels in norm will be on the top of one of humps. Add as reducing the intensity of nerve signals coming here from the centres, will reduce the vascular tone muscles, and the vessel will expand.
It seems likely that, in addition, in hard conditions of work the heart is increasingly using mechanisms that are open grandfather Shchukarev: not by accident in the heart in the pericardium occurs negative pressure.
Coronary vessels is very sensitive to mechanical irritation, i.e. variation of pressure in them" in other words, there is a strong autoregulatory reaction. However, nobody managed to call in the experiment myocardial infarction by nervous or autoregulatory effects on coronary vessels. Even while extremely excited all of the vegetative nervous system as a whole using restriction of blood flow to the brain when there is a significant narrowing of coronary vessels, experimental infarction is not developing. However, it often occurs in people with great excitement - a clear reference to the value of the nervous regulation in this disease. However, under emotional stress is excited sympatho-adrenal system: the sympathetic nervous system is raging, and in the blood increases the concentration of adrenaline. In the experiment and the first and the second leads to the expansion of the coronary vessels. However, we must take into account and palpitations, increased blood pressure, both of these factors increase oxygen request of the infarction, and if the flow is increased enough that the situation is dangerous. The same can be said about any load: muscular, temperature etc.
What can prevent the development of coronary blood flow to the desired values in the case of increased oxygen question? Of course, obstacle can serve as a mechanical barrier, for example atherosclerotic plaque in the coronary artery. So really happens. Modern methods of researches allow to pinpoint the location of obstacles and even to enter into the damaged vessel dilator without opening the chest, through the vasculature of the leg. But there are many unexplained.
Even seriously wounded heart attack heart muscle continues to work and don't ask to be freed from duties due to illness: a heavy condition in these cases happens when upset reflex regulation of circulation due to the fact that failed many receptors of the heart. Many studies suggests that all circulatory disorder, dangerous to life after a heart attack, are caused not so much by the weakening of the contractile force of the heart muscle, but mainly reflex nature, i.e. arise from deafferentation heart.
All this gives us grounds to consider that the failure when changing hearts largely related to the fact that the transplanted heart is not sending the centers of information about their work. But this operation make such patients because of a severe atherosclerosis still faulty and service vessels. So it seems to us expedient at heart transplant to try to save the Atria recipient rich receptors, together with ears fibrillation. Although ears and less full of sensitive nerve endings than the Atria, but we know that in difficult minute and insignificant, it would seem that the impulses from the heart to vasomotor (vasomotor) the center can be of vital importance. Indeed, transplantation of parts of the heart gives a large percentage of successful outcomes.
Probably the most promising to plant a second heart, with innervation own heart is not broken, the time of coexistence in the body of two hearts is sufficient to sensitive nerves sprang to the new heart. Seems probable another option: the lack of activity from the heart may be filled with irritation - artificial - some centripetal nerves to the parts of the nerve centers, which gained the reputation of vasomotor. To some extent this role can take on the hearing nerves, able to some extent to substitute the afferent impulses on the vagus nerves. When the dogs were transplanted their own, just deleted the heart, the surviving dogs cope with heavy loads, for example, ran almost as good as healthy, although this places high demands on the heart. Heart change the behavior, but with a delay and in a smaller range than normal. This is typical for humoral regulation. But if vasomotor center does not receive signals about the work of the heart - it is bad, not because of the heart, and because of the vessels, losing neurogenic tone.
As we see, the heart difficult to maintain their own homeostasis. The hardest, probably due to reasons mechanical properties and high oxygen demand. By the way, is worthy of attention the fact that the heart and lungs, i.e. bodies with the mighty interoceptive, in particular mechanoreceptive, protected from external mechanical influences. As the poet said,
...heart locked in a cage,
Although breast.
The most radical tool in the struggle with coronary disease and its consequences - the reasonable organization of mode of life. Train your heart and muscles, this is probably the most important for prevention of cardiovascular diseases. Know the measure, however! And do not smoke. The rest of you, probably, know of the many books and mouth. Perhaps recall only one advice known therapist: each tablespoon of positive emotions. Respect to your heart! And to the hearts of others. The second no less important than the first.
Your physical performance (and largely mental!) is determined by the efficiency of the circulatory system. Know about it, sitting by the fire, hanging under the sails and shooting deer!