The innervation of the heart and its physiological features is information without which it will be difficult to clearly imagine all the facets of this important organ in the human body. It is interesting enough to know how the brain binds to the center of the circulatory system in our body. In addition, the structure and principles of cardiac functioning also deserve attention.
Heart work
The key, one might even say, central organ of the circulatory system of the human body is the heart. It is hollow, has the shape of a cone and is located in the chest cavity. If we describe its function using extremely simple images, then we can say that the heart works like a pump, due to which the blood flow necessary for the full functioning of the body is preserved in a complex system of arteries, blood vessels and veins.
An interesting fact is that the heart is capable of producing its own electrical activity. A quality such as automation is defined. This feature allows even an isolated cell of the heart muscle to contract by itself. This quality is extremely important for the stable operation of this body.
Structural features
Initially, the scheme of the heart makes you pay attention to where this organ is located. It is located, as described above, in the chest cavity, and so that the smaller part is localized on the right, and the larger, respectively, on the left. So it’s wrong to think that the whole heart is on the left side of the chest.
But more precisely, the place where the heart is located is the mediastinum, in which there are two so-called floors - the lower and the upper.
The size of the heart is on average equal to the volume of the hand, which is clenched into a fist. It is worth knowing that the heart is divided by a special partition into two halves - left and right. In turn, each of these parts has such departments as the ventricle and atrium, between which there is an opening. It closes by means of a folding valve. A feature of this valve is its structure: in its right side it has three wings, and in the left - two.
Right ventricle
In this case, we are talking about a cavity on the inside of which there are many muscle bars. Papillary muscles are also located here. It is from them that tendon filaments go to that valve, which closes the hole between the right ventricle and the right atrium.
As for the mentioned valve, its structure includes three valves, built of endocardium. As soon as the right ventricle contracts, this valve closes the opening, which ultimately blocks the reverse flow of blood. By the way, it is from this part of the heart that the pulmonary trunk goes to the respiratory organ. Venous blood moves along it.
Left ventricle
If we compare it with the right one, it should be noted that in this case the wall is noticeably thicker. Paying attention to the inner surface of its wall, you can notice the muscular bars and papillary muscles. It is from them that tendon filaments depart, which are fixed on the edges of the left atrioventricular valve.
Left ventricle of the heart It is also the place from which the largest arterial trunk, called the aorta, emerges. It is above the valve of this trunk that the holes leading to the coronary arteries that feed the heart are located.
It is important to know that all arterial blood enters the left atrium and from here it enters the left ventricle, which was discussed above. As you can see, all the elements of the heart are closely connected and if one of them fails, this will affect the entire organ.
Vessels
Speaking about the vessels through which the blood supply to the heart is carried out, it is worth noting that they pass along the external side of the organ in special grooves. Moreover, there are those that enter the heart, and those that come out of it.
There are also longitudinal interventricular grooves on the lower and anterior ventricular surface. There are two such furrows - the posterior and the anterior, but both of them are directed to the apex of the organ.
Do not forget about the coronal groove, which is localized between the lower and upper chambers. Right and left coronary arteries of the heart, more precisely, their branches are located precisely in it. Their mission is to nourish this organ with blood. That is why, if a cholesterol plaque forms in this area or a blood clot enters, a person’s life is at risk.
At the same time, there are also other large arteries of the heart, as well as venous trunks that leave this organ.
Valves
These elements are attached to the so-called skeleton of the heart, which consists of two fibrous rings. Those, in turn, are located between the upper and lower chambers.
There are only 4 valves in the human heart.
The first (conditionally) is called the right atrioventricular, or tricuspid. Its main function is to block the possibility of reverse blood flow from the right ventricle.
The next, left valve, has only two leaves, which is why it received the corresponding name - bicuspid. It can also be called the mitral valve. It is necessary for the formation of a valve that does not allow blood to flow from the left atrium into the left ventricle of the heart.
The third valve - without it, the opening of the pulmonary column would remain open. This would lead to blood flowing back into the ventricle.
The heart diagram also includes the fourth valve, which is located at the place where the aortic exit is located. It does not allow blood flow to go back to the heart.
What you should know about the conductive system
Blood supply to the heart is not the only function on which the stable operation of this organ depends. Extremely important is the formation of a heartbeat. It is thanks to the conducting system that the contraction of the muscle layer is created, which serves as the beginning of the work of the main organ of the circulatory system.
It is important to note the fact that the sinus-atrial node is the place where the impulse is generated, giving the command to contract the heart muscle. As for the location, it is located where the vena cava passes into the right atrium.
The structures described above have such an effect on the heart, due to which the following processes become possible:
- coordination of ventricular and atrial contractions;
- rhythmic pulse generation;
- synchronous involvement of all cells of the muscle layer of the ventricles in the contractile process (without this, increasing the effectiveness of contractions would be an extremely difficult task).
Innervation of the heart
Initially, you should understand what this terminology implies. So, innervation is nothing more than saturating a specific part of the body with nerves for a stable and complete connection with the central nervous system. In other words, it is the neural network through which the brain controls muscles and organs. A similar peculiarity of the organism cannot be ignored when studying such a topic as the structure and work of the heart.
A more detailed study of this topic can begin with the following fact: the process of contraction of the heart muscle is controlled by both the endocrine and nervous systems. At the same time, the vegetative innervation of the heart has the most direct effect on changes in the rhythm of contractions. We are talking about sympathetic and parasympathetic stimulation. The first increases the frequency of contractions, the second, respectively, reduces it.
The general activities of this body are controlled by the cardiac centers of the parsley bridge and medulla oblongata. From these centers, with the help of sympathetic and parasympathetic nerve fibers, impulses are transmitted that affect the strength of contractions, their frequency and speed of trioventricular conduction. As for the transmission scheme of nerve effects on the heart, here this role, as in any other organs, is played by mediators. In the sympathetic system, this is norepinephrine, and acetylcholine in the parasympathetic, respectively.
Characteristic features of cardiac innervation
The intraorgan nerve apparatus of the heart is quite complicated. It is represented by nerves, which begin their journey from the pectoral aortic plexus and only then enter the main organ of the circulatory system, as well as the ganglion. The latter are nothing but a cluster of cells located in the center of the apparatus mentioned above. Nerve fibers are also part of this system. They start from the heart ganglia. Effectors and receptors make this structure full.
Innervation of the heart also implies the presence of sensitive fibers. They consist of spinal nodes and the vagus nerve. Vegetative motor fibers also belong to this group.
Sympathetic fibers
So, if you pay attention to such a facet of the topic under consideration, as the sympathetic innervation of the heart, then it’s worth initially paying attention to the source of these fibers. In other words, determine where they come from to the central organ of the circulatory system. The answer is quite simple: the lateral horns of the upper thoracic segments of the spinal cord.
The essence of the effect of sympathetic stimulation is reduced to the effect on the force of contraction of the ventricles and atria, which is expressed in its increase. In fact, we are talking about a positive inotropic effect. But that's not all - heart rate is increasing. In this case, it makes sense to talk about a positive chronotropic effect. And the last effect of sympathetic innervation that you should pay attention to is the dromotropic effect, namely, the effect on the interval between contractions of the ventricles and atria.
Parasympathetic part of the system
The innervation of the heart also includes these processes. This type of fiber approaches the heart as part of the vagus nerve, on both sides.
If we talk about the "right" fibers, then their function is reduced to innervation, respectively, of the right atrium as well. In the area of the sinus-atrial node, they form a dense plexus. As for the left vagus nerve, the fibers that come with it go to the atrioventricular node.
Speaking about the effect that the parasympathetic innervation of the heart produces, it is worth mentioning a decrease in the strength of atrial contraction and a decrease in heart rate. But the atrioventricular delay increases. It is not difficult to conclude that the work of nerve fibers plays a more than significant role in the work of the circulatory system.
Prevention
Against the background of possibly complex information about what the heart is, it makes sense to pay a little attention to simple actions that will help keep it in working condition for many years.
So, given the features of the structure and work of the heart, we can conclude that the health of this organ depends on the state of three elements: muscle tissue, blood vessels and blood flow.
In order for everything to be good with the heart muscle, you need to give it a moderate load. This mission is perfectly performed by jogging (without fanaticism) or walking. Such exercises harden the main organ of the circulatory system.
Now a little about the vessels. In order for them to be in shape, you need to eat right. This means that you have to say goodbye forever to large and stable portions of fatty foods and competently build your diet. The body must receive all the necessary nutrients and vitamins, then everything will be fine.
And the last guarantee of the long work of the heart, and of the whole body, is good blood flow. Here one simple secret will come to the rescue: by all evening, blood thickens in all people. And if we are talking about representatives of the middle age group, then such a consistency in some cases becomes dangerous, causing a risk of heart attack or stroke. To correct the situation will help evening walks in the lap of nature. Where there are trees, lakes, the sea, mountains or waterfalls - a high concentration of ionized air, which significantly improves blood flow.
Conclusion
Based on all the above information, one can come to an obvious conclusion: the innervation of the heart, the physiology of this organ and its work as a whole will always be important topics that do not lose their relevance. Indeed, without this knowledge, the level of which is constantly deepening, it is difficult to imagine an effective diagnosis and competent treatment of the heart.