Blood and lymph vessels of the heart

The arteries of the heart move away from the bulb of the aorta - the initial enlarged part of the ascending part of the aorta. These arteries, like a crown, surround the heart, and in this connection they are called coronary arteries. The right coronary artery starts at the level of the right sine of the aorta, and the left one - at the level of its left sinus. Both arteries move away from the aorta below the free (upper) edges of the semilunar dampers, so during the ventricular contraction (systole) the dampers cover the openings of the arteries and almost do not pass the blood to the heart. With the relaxation (diastole) of the ventricles, the sinuses fill with blood, closing the path from the aorta back to the left ventricle. At the same time, the access of blood to the vessels of the heart is opened.

The right coronary artery (a.coronaria dextra) goes to the right under the eye of the right atrium, lies in the coronary groove, rounds the right (pulmonary) surface of the heart. Then the artery follows the back of the heart to the left, where it ends with an anastomosis with the enveloping branch of the right coronary artery. The largest branch of the right coronary artery is the posterior interventricular branch (r.interventricularis posterior), which is guided along the epithelium of the heart with the same name toward its apex. The branches of the right coronary artery supply the right ventricle and atrium walls, the posterior part of the interventricular septum, the papillary muscles of the right ventricle, the posterior papillary muscle of the left ventricle, the sinus-atrial and the atrioventricular nodes of the conduction system of the heart.

The left coronary artery (a.coronaria sinistra) is somewhat thicker than the right, located between the beginning of the pulmonary trunk and the auricle of the left atrium. It is divided into two branches: the anterior interventricular branch (r.interventricularis anterior) and the envelope branch (r.circumflexus). The latter, which is a continuation of the main trunk of the coronary artery, traverses the heart on the left, located in its coronal sulcus. On the back of the organ this branch is anastomosed with the right coronary artery. The anterior interventricular branch follows the same groove of the heart toward its apex. In the area of cardiac notch this branch sometimes passes to the diaphragmatic surface of the heart, where it is anastomosed with the terminal section of the posterior interventricular branch of the right coronary artery. The branches of the left coronary artery supply blood to the left ventricle, including papillary muscles, most of the interventricular septum, the anterior wall of the right ventricle, and the left atrial wall.

The branches of the right and left coronary arteries, joining, form as it were two arterial rings around the heart: transverse in the coronary fissure and longitudinal, vessels of which are in the anterior and posterior interventricular furrows.

The branches of the coronary arteries ensure blood supply to all layers of the heart walls. In the myocardium, where the level of oxidation processes is highest, the microvessels that anastomose with each other repeat the course of the muscle bundles.

There are different options for the distribution of branches of the coronary arteries, which are called types of blood supply to the heart. The main ones are:

• legal type - most parts of the heart are supplied with branches of the right coronary artery;
• the left type - most of the heart receives blood from the branches of the left coronary artery;
• average, or uniform, type - both coronary arteries are evenly distributed in the walls of the heart.

There are also transitional types of blood supply to the heart - middle right and middle left. It is generally believed that among all types of blood supply to the heart, the middle-right type is predominant.

Variants and anomalies of the position and branching of the coronary arteries are possible. They are manifested in the change in the place of origin and in the number of coronary arteries. So, the arteries can move away from the aorta directly above the semilunar valves or much higher - from the left subclavian artery, and not from the aorta. The venous artery can be unique, i.e. Unpaired; there may be 3-4 coronary arteries, and not two: two arteries extend to the right and left of the aorta or two from the aorta and two from the left subclavian artery.

Along with the coronary arteries, non-permanent (additional) arteries go to the heart (especially to the pericardium). These may be the mediastinal pericardial branches (upper, middle and lower) of the internal thoracic artery, the branches of the pericardodiofagmagic artery, as well as branches extending from the concave surface of the aortic arch, and others.

The veins of the heart are more numerous than the arteries. Most of the large veins of the heart gather into one common wide venous vessel - the coronary sinus (sinus coronarius) - the remainder of the embryonic left common cardial vein. The sinus is located in the coronal sulcus on the posterior surface of the heart and opens into the right atrium below and anterior to the opening of the inferior vena cava (between its damper and the interatrial septum). Inflows of the coronary sinus are 5 veins:

1. a large vein of the heart (v.cardiaca magna), which begins at the apex of the heart on the front of its surface. This vein lies in the anterior interventricular sulcus next to the anterior interventricular branch of the left coronary artery. Then, at the level of the coronal sulcus, the vein turns left, passes under the envelope branch of the left coronary artery, lies in the coronary groove on the posterior surface of the heart, where it continues into the coronary sinus. A large vein of the heart collects blood from the veins of the anterior surface of both ventricles and the interventricular septum. The veins of the posterior surface of the left atrium and left ventricle also enter the large vein of the heart;
2. the middle vein of the heart (v.cardiaca media) is formed in the region of the posterior surface of the apex of the heart, rises up the posterior interventricular sulcus (adjacent to the posterior interventricular branch of the right coronary artery) and falls into the coronary sinus;
3. a small vein of the heart (v.cardiaca parva) starts on the right (pulmonary) surface of the right ventricle, rises, lies in the coronary groove on the diaphragmatic surface of the heart and falls into the coronary sinus. This vein collects blood mainly from the right side of the heart;
4. the posterior vein of the left ventricle (v.posterior ventriculi sinistri) is formed from several veins on the posterior surface of the left ventricle, closer to the apex of the heart and falls into the coronary sinus or into the greater vein of the heart;
5. The oblique vein of the left atrium (v.obhqua atrii sinistri) follows from the top down the posterior surface of the left atrium and empties into the coronary sinus.

In addition to the veins that flow into the coronary sinus, the veins have veins that open directly into the right atrium. These are the front veins of the heart (vv.cardiacae anteriores), which collect blood from the anterior wall of the right ventricle. They go up to the base of the heart and open into the right atrium. The smallest veins of the heart (the vasic veins, vv.cardiacae minimae), only 20-30, begin in the thickness of the walls of the heart and flow directly into the right atrium and partly into the ventricles and the left atrium through the orifices of the smallest veins.

The lymphatic channel of the walls of the heart consists of lymphatic capillaries, located in the form of networks in the endocardium, myocardium and epicardium. Lymph from the endocardium and myocardium flows into the superficial network of lymphatic capillaries located in the epicardium and into the plexus of lymphatic vessels. Connecting with each other, the lymphatic vessels grow larger and form the two main vessels of the heart, through which lymph flows to the regional lymph nodes. The left lymphatic vessel of the heart is formed from the fusion of the lymphatic vessels of the anterior surfaces of the right and left ventricles, the left pulmonary and the posterior surfaces of the left ventricle. It follows from the left ventricle to the right, passes behind the pulmonary trunk and flows into one of the lower tracheobronchial lymph nodes. The right lymphatic vessel of the heart is formed from the lymphatic vessels of the anterior and posterior surfaces of the right ventricle, directed from right to left along the anterior semicircle of the pulmonary trunk and empties into one of the anterior mediastinal lymph nodes located near the arterial ligament. The small lymphatic vessels, through which the lymph flows from the walls of the atria, flow into the nearby anterior mediastinal lymph nodes.

[1], [2], [3], [4], [5], [6]