Innervation of the heart and its physiological characteristics - information without which it will be difficult to clearly imagine all the facets of the work of this important organ in the human body. It is interesting enough to know how the brain communicates with 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, the 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 you describe its function using extremely simple images, then we can say that the heart works like a pump, thanks to which the blood flow necessary for the full functioning of the body is maintained in a complex system of arteries, vessels and veins.
Interesting is the fact that the heart is capable of producing its own electrical activity. Such quality as automation is defined. This feature allows even an isolated cell of the heart muscle to contract on its own. This quality is extremely important for the stable operation of this body.
Building features
Initially, the diagram of the heart makes you pay attention to where this organ is located. It is locatedas written above, in the chest cavity, and in such a way that its smaller part is localized on the right, and the larger one, respectively, on the left. So thinking that the whole heart is on the left side of the chest is wrong.
But more precisely, the place where the heart is located is the mediastinum, in which there are two so-called floors - lower and 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 the atrium, between which there is an opening. It closes with a flap valve. The peculiarity of this valve is its structure: on its right side it has three flaps, and on the left side it has two.
Right ventricle
In this case, we are talking about a cavity, on the inside of which there are many muscle bars. The papillary muscles are also located here. It is from them that the tendon filaments depart to the valve that closes the hole between the right ventricle and the right atrium.
As for the mentioned valve, its structure includes three leaflets built from the endocardium. As soon as the right ventricle contracts, this valve closes the opening, which eventually blocks the return flow of blood. By the way, it is from this part of the heart that the pulmonary trunk comes out, going to the respiratory organ. Venous blood moves through it.
Left ventricle
If you compare it with the right one, you neednote that in this case the wall is noticeably thicker. Paying attention to the inner surface of its wall, you can see the muscle crossbars and papillary muscles. It is from them that the tendon threads depart, which are fixed on the edges of the left atrioventricular valve.
The left ventricle of the heart is also the place from which the largest arterial trunk, called the aorta, emerges. It is above the valve of this trunk that the openings 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 there 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, it will affect the entire organ.
Vessels
Speaking of the vessels through which the heart is supplied with blood, it is worth noting that they pass along the outside of the organ in special grooves. Moreover, there are those who enter the heart, and those that come out of it.
There are also longitudinal interventricular sulci on the inferior and anterior ventricular surfaces. There are two such furrows - back and front, but both of them are directed to the top of the organ.
Do not forget about the coronal sulcus, which is localized between the lower and upper chambers. The right and left coronary arteries of the heart, or rather, their branches, are located in it. Their mission is to nourish this organ with blood. That is why, if cholesterol is formed in this areaa plaque or a blood clot gets there, 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 exit 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 flaps, which is why it got the corresponding name - double-leaf. It may also be called the mitral valve. It is necessary to form a valve that prevents blood from flowing from the left atrium into the left ventricle of the heart.
Third valve - without it, the opening of the pulmonary column would remain open. This would cause blood to flow back into the ventricle.
The diagram of the heart also includes a fourth valve, which is located in the place where the exit of the aorta is located. It prevents blood flow back to the heart.
What you should know about the conductive system
The blood supply to the heart is not the only function on which the stable operation of this organ depends. The formation of a heartbeat is also extremely important. It is thanks to the conduction system that a 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 sinoatrial node is the place where an impulse is generated that gives the command to contract the heart muscle. As for its location, it is located where the vena cava passes into the right atrium.
The structures described above have such an effect on the heart that 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 efficiency of contractions would be an extremely difficult task).
Innervation of the heart
Initially, it is worth understanding what this terminology implies. So, innervation is nothing more than the saturation of a specific part of the body with nerves for a stable and complete connection with the central nervous system. In other words, it is a neural network through which the brain controls the muscles and organs. A similar feature of the body cannot be ignored when studying such a topic as the structure and function of the heart.
A more detailed study of this topic can begin with this fact: the process of contraction of the heart muscle is controlled by both the endocrine and nervous systems. At the same time, autonomic innervation of the heart has the most direct influence on changes in the rhythm of contractions. We are talking about sympathetic and parasympathetic stimulation. Firstincreases the frequency of contractions, the second, respectively, reduces it.
The overall activity of this organ is controlled by the heart centers of the pons 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 the speed of trioventricular conduction. As for the scheme of transmission of nerve influences on the heart, here, as in any other organs, mediators play this role. In the sympathetic system, this is norepinephrine, and acetylcholine in the parasympathetic, respectively.
Characteristic features of cardiac innervation
The intraorgan nervous apparatus of the heart is rather complicated. It is represented by nerves that start their journey from the thoracic aortic plexus and only then enter the main organ of the circulatory system, as well as the ganglia. The latter are nothing more than an accumulation of cells located in the center of the apparatus mentioned above. Nerve fibers are also part of this system. They originate from the cardiac ganglia. Effectors and receptors make this structure complete.
Innervation of the heart also implies the presence of sensory fibers. They consist of the spinal nodes and the vagus nerve. This group also includes autonomic motor fibers.
Sympathetic fibers
So, if you pay attention to such a facet of the topic under consideration as the sympathetic innervation of the heart, then initially you should pay attention to the source of these fibers. In other words, determine where they come fromthe 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 - the heart rate increases. In this case, it makes sense to talk about a positive chronotropic effect. And the last effect of sympathetic innervation that should be paid attention to is the dromotropic effect, namely, the effect on the interval between ventricular and atrial contractions.
Parasympathetic part of the system
Innervation of the heart also includes these processes. This type of fiber approaches the heart as part of the vagus nerve, and from both sides.
If we talk about the "right" fibers, then their function is reduced to the innervation of the right atrium, respectively. In the region of the sinoatrial node, they form a dense plexus. As for the left vagus nerve, the fibers that go with it go to the atrioventricular node.
Speaking of the effect that the parasympathetic innervation of the heart produces, it is worth mentioning the decrease in the force of atrial contraction and the decrease in heart rate. But the atrioventricular delay increases. It is easy to conclude that the work of nerve fibers plays a more than significant role in the functioning of the circulatory system.
Prevention
Against the background of perhaps complex information about what a heart is, it makes sense to pay a little attention to simplesteps that will help keep it running for many years to come.
So, considering what features the structure and work of the heart has, we can conclude that the he alth 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 fulfilled 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 will have to say goodbye to large and stable portions of fatty foods forever and build your diet wisely. The body must receive all the necessary nutrients and vitamins, then everything will be fine.
And the last guarantee of a long work of the heart, and of the whole body, is a good blood flow. Here one simple secret will come to the rescue: in the evening, the 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 the risk of a heart attack or stroke. Evening walks in the bosom of nature will help to correct the situation. Where there are trees, lakes, sea, mountains or waterfalls, there is a high concentration of ionized air, which significantly improves blood flow.
Conclusion
Based on all the above information, we can come to an obvious conclusion: the innervation of the heart, the physiology of this organ and its work in generalwill 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 effective diagnosis and competent treatment of the heart.
