Anterior coronary artery. Blood vessels of the heart: coronary arteries and veins of the heart. Types of blood supply to the heart. Lymphatic drainage

The arteries of the heart arise from the aortic bulb and surround the heart like a crown, which is why they are called coronary arteries.

Right coronary artery goes to the right under the appendage of the right atrium, lies in the coronary sulcus and goes around the right surface of the heart. The branches of the right coronary artery supply blood to the walls of the right ventricle and atrium, the posterior part of the interventricular septum, the papillary muscles of the left ventricle, the sinoatrial and atrioventricular nodes of the conduction system of the heart.

Left coronary artery thicker than the right and located between the beginning of the pulmonary trunk and the appendage of the left atrium. The branches of the left coronary artery supply blood to the walls of the left ventricle, the papillary muscles, most of the interventricular septum, the anterior wall of the right ventricle, and the walls of the left atrium.

The branches of the right and left coronary arteries form two arterial rings around the heart: transverse and longitudinal. They provide blood supply to all layers of the walls of the heart.

There are several types of blood supply to the heart:

• right coronary type - most parts of the heart are supplied with blood by the branches of the right coronary artery;
• left coronary type - most of the heart receives blood from the branches of the left coronary artery;
• uniform type - blood is evenly distributed throughout the arteries;
• middle right type - transitional type of blood supply;
• middle-left type - transitional type of blood supply.

It is believed that among all types of blood supply, the middle-right type is predominant.

Veins of the heart more numerous than arteries. Most of the large veins of the heart gather in coronary sinus- one common wide venous vessel. The coronary sinus is located in the coronary sulcus on the posterior surface of the heart and opens into the right atrium. The tributaries of the coronary sinus are 5 veins:

• great vein of the heart;
• middle vein of the heart;
• small vein of the heart;
• posterior vein of the left ventricle;
• oblique vein of the left atrium.

In addition to these five veins, which flow into the coronary sinus, the heart has veins that open directly into the right atrium: anterior veins of the heart, And smallest veins of the heart.

Autonomic innervation of the heart.

Parasympathetic innervation of the heart

Preganglionic parasympathetic cardiac fibers are part of the branches that arise from the vagus nerves on both sides in the neck. Fibers from the right vagus nerve innervate predominantly the right atrium and especially abundantly the sinoatrial node. The atrioventricular node is approached mainly by fibers from the left vagus nerve. As a result, the right vagus nerve predominantly affects the heart rate, and the left one affects atrioventricular conduction. Parasympathetic innervation of the ventricles is weakly expressed and exerts its influence indirectly, due to the inhibition of sympathetic effects.

Sympathetic innervation of the heart

Sympathetic nerves, unlike the vagus nerves, are almost evenly distributed throughout all parts of the heart. Preganglionic sympathetic cardiac fibers originate in the lateral horns of the upper thoracic segments spinal cord. In the cervical and superior thoracic ganglia of the sympathetic trunk, in particular in the stellate ganglion, these fibers switch to postganglionic neurons. The processes of the latter approach the heart as part of several cardiac nerves.

In most mammals, including humans, ventricular activity is controlled primarily by sympathetic nerves. As for the atria and, especially, the sinoatrial node, they are under constant antagonistic influences from the vagus and sympathetic nerves.

Afferent nerves of the heart

The heart is innervated not only by efferent fibers, but also by a large number of afferent fibers running as part of the vagus and sympathetic nerves. Most of the afferent pathways belonging to vagus nerves, are myelinated fibers with sensory endings in the atria and left ventricle. When recording the activity of single atrial fibers, two types of mechanoreceptors were identified: B-receptors, responding to passive stretch, and A-receptors, responding to active tension.

Along with these myelinated fibers from specialized receptors, there is another large group sensory nerves extending from the free endings of the dense subendocardial plexus of soft fibers. This group of afferent pathways is part of the sympathetic nerves. It is believed that these fibers are responsible for sharp pains with segmental irradiation, observed with coronary disease heart (angina pectoris and myocardial infarction).

Heart development. Anomalies of the position and structure of the heart.

Heart development

The complex and unique structure of the heart, corresponding to its role as a biological engine, takes shape in the embryonic period. In the embryo, the heart goes through stages when its structure is similar to the two-chambered heart of fish and the incompletely occluded heart of reptiles. The heart rudiment appears during the neural tube period in an embryo of 2.5 weeks, having a length of only 1.5 mm. It is formed from cardiogenic mesenchyme ventral to the head end of the foregut in the form of paired longitudinal cellular strands in which thin endothelial tubes are formed. In the middle of the 3rd week, in an embryo 2.5 mm long, both tubes merge with each other, forming a simple tubular heart. At this stage, the heart rudiment consists of two layers. The inner, thinner layer represents the primary endocardium. Outside there is a thicker layer consisting of the primary myocardium and epicardium. At the same time, the pericardial cavity, which surrounds the heart, expands. At the end of the 3rd week, the heart begins to contract.

Due to its rapid growth the heart tube begins to bend to the right, forming a loop, and then takes an S-shape. This stage is called the sigmoid heart. At the 4th week, several parts can be distinguished in the heart of an embryo 5 mm long. The primary atrium receives blood from the veins converging to the heart. At the junction of the veins, an extension is formed called the venous sinus. From the atrium, blood enters the primary ventricle through the relatively narrow atrioventricular canal. The ventricle continues into the bulbus cordis, followed by the truncus arteriosus. At the junction of the ventricle with the bulb and the bulb with the truncus arteriosus, as well as on the sides of the atrioventricular canal, there are endocardial tubercles from which the heart valves develop. The structure of the embryonic heart is similar to the two-chambered heart of an adult fish, the function of which is to supply venous blood to the gills.

During the 5th and 6th weeks, significant changes occur in relative position parts of the heart. Its venous end moves cranially and dorsally, and the ventricle and bulb move caudally and ventrally. The coronary and interventricular grooves appear on the surface of the heart, and it acquires, in general terms, a definitive external form. During the same period they begin internal transformations, which lead to the formation of a four-chambered heart, characteristic of higher vertebrates. The heart develops septa and valves. The division of the atria begins at an embryo of 6 mm in length. In the middle of it back wall the primary septum appears, it reaches the atrioventricular canal and merges with the endocardial tubercles, which by this time increase and divide the canal into right and left parts. The septum primum is not complete; first the primary and then the secondary interatrial foramina are formed in it. Later, a secondary septum is formed, in which there is an oval opening. Through the foramen ovale, blood passes from the right atrium to the left. The hole is covered by the edge of the septum primum, forming a valve that prevents the reverse flow of blood. Complete fusion of the primary and secondary septa occurs at the end of the intrauterine period.

During the 7th and 8th weeks embryonic development partial reduction occurs venous sinus. Its transverse part is transformed into the coronary sinus, the left horn is reduced to a small vessel - the oblique vein of the left atrium, and the right horn forms part of the wall of the right atrium between the places where the superior and inferior vena cava flow into it. IN left atrium the common pulmonary vein and the trunks of the right and left pulmonary veins are retracted, as a result of which two veins from each lung open into the atrium.

At 5 weeks old, the bulb of the heart merges with the ventricle in the embryo, forming the arterial cone belonging to the right ventricle. Truncus arteriosus It is divided by the spiral septum developing in it into the pulmonary trunk and the aorta. From below, the spiral septum continues towards the interventricular septum in such a way that the pulmonary trunk opens into the right, and the beginning of the aorta into the left ventricle. Endocardial tubercles located in the bulb of the heart take part in the formation of the spiral septum; due to them, the valves of the aorta and pulmonary trunk are also formed.

The interventricular septum begins to develop at the 4th week, its growth occurs from bottom to top, but until the 7th week the septum remains incomplete. In its upper part there is an interventricular foramen. The latter is closed by the growing endocardial tubercles, in this place the membranous part of the septum is formed. The atrioventricular valves are formed from the endocardial tubercles.

As the heart chambers divide and valves form, the tissues that make up the heart wall begin to differentiate. The atrioventricular conduction system is distinguished in the myocardium. The pericardial cavity is separated from common cavity bodies. The heart moves from the neck to the chest cavity. The embryonic and fetal hearts have relatively big sizes, since it ensures not only the movement of blood through the vessels of the fetal body, but also placental blood circulation.

Throughout the prenatal period, communication is maintained between the right and left halves of the heart through the foramen ovale. Blood entering the right atrium through the inferior vena cava is directed through the valves of this vein and the coronary sinus to foramen ovale and through it into the left atrium. From the superior vena cava blood is flowing into the right ventricle and ejected into the pulmonary trunk. The pulmonary circulation of the fetus does not function, since the narrow pulmonary vessels provide great resistance to the flow of blood. Only 5-10% of the blood entering the pulmonary trunk passes through the fetal lungs. The rest of the blood is drained ductus arteriosus into the aorta and enters the systemic circulation, bypassing the lungs. Thanks to the foramen ovale and the ductus arteriosus, the balance of blood flow through the right and left halves of the heart is maintained.

Most important organ in the body it is the heart. For its full functioning, it requires a sufficient amount of oxygen and nutrients.

Based human structure, we can confidently say that there is a systemic and pulmonary circulation. There is also an additional one - coronal.

It is formed by coronary types of arteries, veins, and capillaries. You should learn more about its purpose and possible pathologies.

Structure and principle of operation

The coronary arteries of the heart are the main channels that supply myocardial cells with everything they need (oxygen and microelements). They also promote the outflow of venous blood.

It is known that two such vessels depart from the heart - the right and left coronary arteries. It is worth taking a closer look at their mechanism of operation and structure.

The coronary anatomy of such vessels provides for their very small size and smooth surface. In the case of abnormal processes, a change in appearance, deformation and stretching are observed. To create an additional circle of blood circulation, the vessels are placed near the largest of them - the blood trunk, thus, the type of artery in question forms a kind of loop, a ring.

Filling of the vessels with blood occurs when the characteristic organ relaxes, while contraction of the myocardium is accompanied by the outflow of blood.

Moreover, in various cases blood consumption is different.

For example, when playing sports or lifting weights, the human body needs more oxygen, as a result of which the vessels have to stretch. Only absolutely healthy vessels can withstand such a load.

Existing varieties

The anatomical structure suggests that the coronary artery is divided into two parts: left and right.

If we look from the point of view of surgery, we can distinguish the following components of the coronary bed:

1. Bending branch. It comes off from the left side of the vessel. It is necessary to nourish the wall of the left ventricle directly. If there is any damage, then gradual erasure of the branch occurs.
2. Subendocardial types of arteries. They are classified as part of the general circulatory system. Despite the fact that these types of vessels are classified as coronary arteries, they are located deep in the heart muscle.
3. Interventricular anterior branch. Saturates important elements characteristic organ and interventricular septum.
4. Right coronary artery. It supplies the right ventricle of the main organ with microelements and partially provides it with oxygen.
5. Left coronary artery. Its responsibilities include supplying oxygen to all remaining cardiac sections, and has ramifications.

Anatomy coronary arteries is designed in such a way that if there is a disruption in their work, harmful irreversible processes will follow in the functioning of the entire cardiovascular system.

Right coronary vessel

The right coronary artery (or abbreviated RCA) originates from the anterior part of the sinus of Vilsalva and is pumped by the atrioventricular groove.

Coronary blood flow involves the division of the RCA into branches:

• conus arteriosus (supplies the right ventricle);
• sinoatrial node;
• atrial branches;
• right marginal branch;
• intermediate atrial branch;
• posterior interventricular branch;
• septal interventricular branches;
• branches of the atrioventricular node.

Anatomy coronary vessels is such that initially the type of artery in question is located directly in the fatty tissue on the right side of the pulmonary artery.

Then it goes around the human “motor” along right side atrioventricular groove. Then it moves to the posterior wall and reaches the posterior longitudinal groove, descending to the top of the characteristic organ.

Considering the coronary circulation, it can be noted that the process of blood supply to the heart muscle has individual characteristics for every person.

In order to conduct a complete analysis of the structure of such arteries, examination using coronary angiography or angiography is required.

Left coronary vessel

The left coronary artery begins in the left sinus of Valsalva, then moves from the ascending aorta to the left and down the groove of the main organ.

It takes the form of a wide, but at the same time rather short trunk. The length is no more than 9–12 mm.

The branches of the left coronary artery can be divided into 2–3, and in exceptional cases 4 parts. The following branches are of particular importance:

• anterior descending;
• diagonal;
• lateral branch;
• enveloping branch.

However, there are other ramifications. The descending artery usually branches into several smaller lateral branches.

The anterior descending artery lies on the heart muscle, sometimes descending into the myocardium, creating some kind of muscle bridges, the length of which ranges from one to several cm.

The circumflex branch moves away from the left coronary vessel almost at the very beginning (about 0.6–1.8 mm). It also produces a branch that saturates the sinoauricular formation with necessary substances.

The anatomy of the heart is presented in such a way that the coronary vessels have the ability to independently regulate and control the required volume of blood directed to the heart muscle.

Possible pathologies

Coronary blood flow justifiably has great importance for the whole organism as a whole. After all, arteries of this kind are responsible for the blood supply to the main human organ – the heart.

Therefore, damage to these vessels and the development of abnormal processes in them leads to myocardial infarction or ischemic disease.

Blood flow may be impaired due to blockage of blood vessels by plaque or blood clots.

Insufficient blood flow to the left ventricle can result in disability and even death. Stenosis may also develop due to vasoconstriction.

Stenosis of the coronary vessels of the heart leads to the fact that the myocardium cannot fully contract the heart. The doctor usually uses a bypass to restore blood flow.

It is advisable to undergo periodic diagnostics in order to prevent the appearance of stenosis, as well as to promptly treat atherosclerosis. Coronary types of arteries provide blood supply to the main organ in the human body.

If the coronary vessels do not cope with the task and lose elasticity, then the heart experiences a deficiency of vital elements.

This may provoke various diseases"motor" of the human body and even lead to an attack.

The coronary or coronary artery plays important role in the coronary blood supply. The human heart consists of muscles that are constantly, without interruption, in action. For normal operation muscles need a constant flow of blood, which carries the necessary nutrients. These pathways are responsible for supplying blood to the muscles of the heart, that is, coronary blood supply. The coronary blood supply accounts for about 10% of all blood that passes through the aorta.

The vessels that are located on the surface of the heart muscle are quite narrow, despite the amount of blood in percentage, which passes through them. In addition, they are able to regulate blood flow themselves, depending on the needs of the heart. In general, the increase in blood flow can increase up to 5 times.

The coronary arteries of the heart are the only sources of blood supply to the heart, and the supply of the required amount of blood is solely responsible for the function of vascular self-regulation. Therefore, possible stenosis or atherosclerosis of the latter is critically dangerous for human life. Developmental anomalies are also dangerous circulatory system myocardium.

Vessels, weaving around the surface and internal structures of the myocardium, can connect with each other, creating a single network of arterial supply to the heart muscle. There is no connection of the network of vessels only at the edges of the myocardium, since such places are fed by separate terminal vessels.

Everyone's blood supply individual person may vary significantly and is individual. However, it can be noted that there are two trunks of the coronary artery: right and left, which originate from the root of the aorta.

The normal development of the coronary vessels leads to the formation of a vascular network, which appearance vaguely resembles a crown or a crown, which is actually where their name came from. Adequate blood flow is very important for the normal and adequate functioning of the heart muscle. In the event of abnormal development of the vascular network designed to provide blood supply to the heart muscle, significant problems for the latter can arise.

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Doctors' opinion...

Abnormal development of the cardiac vasculature does not occur very often, up to 2% of all cases. This refers only to anomalies that lead to serious violations. For example, in the case of formation of the beginning of the left coronary artery from the pulmonary trunk instead of the aorta. As a result, the heart muscle receives venous blood, which is poor in oxygen and nutrients. The situation is further aggravated by the lack of pressure in the pulmonary trunk; the blood is not only poor, but also supplied in insufficient quantities.

Anomalies of this type are called a defect, and they can be of two types. The first type is caused by insufficient development of bypass pathways of blood flow between the two main branches of the arteries, which leads to a more severe development of the anomaly. The second type is due to well-developed bypass pathways. Then the left part of the heart muscle has the opportunity to receive the missing nutrients from the neighboring pathway. The second type of anomaly assumes a more stable condition of the patient, and does not pose an immediate threat to the latter’s life, but also does not imply any stress.

Blood flow dominance

The anatomical location of the posterior descending branch and the anterior interventricular branch determines the dominance of blood flow. Only in the same case good development of both branches of the coronary blood supply, we can talk about the constancy of the areas of nutrition of each branch, and their usual branches. In the case of better development of one of the branches, a shift occurs in the branching of the branches and, accordingly, in the areas for which they are responsible for nutrition.

Depending on the severity of the coronary tract, right and left types of dominance, as well as co-dominance, are distinguished. Uniform blood supply or codominance is noted when the posterior descending branch is supplied by both branches. Right dominance is noted when the posterior interventricular branch is fed by the right coronary artery; it occurs in 70% of cases. Accordingly, the left type of dominance is noted when feeding from the neighboring bloodstream, and occurs in 10% of cases. Codominance occurs in 20% of all cases.

Right trunk

The right coronary artery supplies blood to the ventricle of the myocardium along with the right atrium, the posterior third of the septum and part of the conus arteriosus. Location: runs from the root along the coronary groove and, going around the edge of the myocardium, reaches the surface of the myocardial ventricle (its posterior part) and the lower surface of the heart. After which it branches into terminal branches: right anterior atrial branching, right anterior ventricular branching. In addition, it is divided into right marginal and posterior ventricular branching. As well as the posterior interventricular branching, the right posterior atrial branching and the left posterior ventricular branching.

Left trunk

The path of the left coronary artery runs to the sternocostal surface of the myocardium between the left auricle and the pulmonary trunk, after which it branches. In 55% of all cases, the length of the latter barely reaches 10 mm.

Supplies blood to most interatrial septum in its back and front. This branch also supplies the left atrium and ventricle. In most cases it has two branches, but sometimes it can branch into three, less often four branches.

The largest branches of this coronary bloodstream, which occur in a greater number of cases, are the circumflex branch and the anterior interventricular branch. Passing from their origin, they branch into smaller vessels, which can connect with small vessels of other branches, creating a single network.

Coronary arteries

stomach and heart. - B. gastric artery(arteriae coronariae ventriculi) arise from the celiac artery (art. coeliaca) or its branches (hepatic artery, splenic, etc.). There are four of them; two of them connect at the lesser curvature of the stomach and thus form the superior arterial arch of the stomach (arcus arteriosus ventriculi superior); the remaining two, merging at the greater curvature, form the lower arterial arch of the stomach. A mass of small branches depart from both arterial arches, which enter the wall of the stomach and here break up into tiny blood stems. B. artery heart (arteria coronaria cordis) - a branch that gives rise to the main vascular trunk of the body (see Aorta), while still in the cavity of the pericardial sac. Beginning with two openings lying approximately at the same height with the free edge of the semilunar valves of the aorta, two V. arteries depart from the expanded part of the latter, called the bulb, and are directed to the anterior surface of the heart, to its transverse groove. Here both V. arteries diverge: the right one goes to the right edge of the heart, goes around it, goes to back surface and along the posterior longitudinal groove it reaches the apex of the heart, into the tissue of which it enters here; the left one first gives off a large branch, reaching along the anterior longitudinal groove to the apex of the heart, then goes to the left edge of the heart, passes to the back and here, at the height of the transverse groove, enters the musculature of the heart. Along their entire length, both V. arteries give off small branches that penetrate into the thickness of the heart wall. The right V. artery supplies blood to the walls of the right atrium, right ventricle, apex of the heart and, partly, the left ventricle; left - apex of the heart, left atrium, left ventricle, ventricular septum. If the lumen of the V. artery is artificially closed or even narrowed in an animal, then after some time the heart stops contracting (heart paralysis), since the heart muscle can work correctly only as long as the V. arteries deliver it the blood necessary for nutrition in sufficient quantities. quantity. On the V. arteries of the human heart there are pathological changes, which affect in a similar way, i.e., they completely stop or significantly reduce the blood flow to the walls of the heart (see Arteriosclerosis, Thrombosis, Embolism) and thereby entail instant death or very painful suffering - myocarditis with its consequences (aneurysm, rupture, heart attack), often angina pectoris, etc.