Aorta, aorta, is the largest arterial vessel in the human body. It exits the left ventricle; its beginning is the opening of the aorta, ostium aortae. All arteries that form the systemic circulation depart from the aorta.

In the aorta, the ascending part of the aorta (ascending aorta), pars ascendens aortae (aorta ascendens), the arch of the aorta, arcus aortae, and the descending part of the aorta (descending aorta), pars descendens aortae (aorta descendens) are distinguished. The latter, in turn, is divided into the thoracic part of the aorta (thoracic aorta), pars thoracica aortae (aorta thoracica), and the abdominal part of the aorta (abdominal aorta), pars abdominalis aortae (aorta abdominalis).

Ascending part of the aorta, pars ascendens aortae, originates in the left ventricle from the aortic opening. Behind the left half of the sternum, at the level of the third intercostal space, it goes up, slightly to the right and forward and reaches the level of the cartilage of the second rib on the right, where it continues into the aortic arch.

The beginning of the ascending part of the aorta is enlarged and is called the aortic bulb, bulbus aortae. The wall of the bulb forms three protrusions - the sinuses of the aorta, sinus aortae, corresponding to the position of the three semilunar valves of the aorta.

Like flaps, these sinuses stand for right, left, and back.

A originates from the right sine. coronaria dextra, and from the left - a. coronaria sinistra.

Aortic arch, arcus aortae, convex upward and directed from front to back, passing into the descending part of the aorta. At the transition site, a slight narrowing is noticeable - the isthmus of the aorta, isthmus aortae. The aortic arch has a direction from the cartilage of the II rib on the right to the left surface of the bodies of the III-IV thoracic vertebrae.

Three large vessels depart from the aortic arch: the brachiocephalic trunk, truncus brachiocephalicus, the left common carotid artery, a. carotis communis sinistra, and the left subclavian artery, a. subclavia sinistra.

The brachiocephalic trunk, truncus brachiocephalicus, departs from the initial part of the aortic arch. It is a large vessel up to 4 cm long, which goes up and to the right and at the level of the right sternoclavicular joint is divided into two branches: the right common carotid artery, a. carotis communis dextra, and the right subclavian artery, a. subclavia dextra. Sometimes the lower thyroid artery departs from the brachiocephalic trunk, a. thyroidea ima.

Development options are rare: 1) the brachiocephalic trunk is absent, the right common carotid and right subclavian arteries depart in this case directly from the aortic arch; 2) the brachiocephalic trunk leaves not to the right, but to the left; 3) there are two brachiocephalic trunks, right and left.

Descending part of the aorta, pars descendens aortae, is a continuation of the aortic arch and lies along the length from the body of the III-IV thoracic vertebra to the level IV of the lumbar vertebra, where it gives off the right and left common iliac arteries, aa. iliacae communes dextra et sinistra, and itself continues into the pelvic cavity in the form of a thin stem - the median sacral artery, a. sacralis mediana, which runs along the anterior surface of the sacrum.

At the XII level of the thoracic vertebra, the descending part of the aorta passes through the aortic opening of the diaphragm and descends into the abdominal cavity. Before the diaphragm, the descending part of the aorta is called the thoracic part of the aorta, pars thoracica aortae, and below the diaphragm, the abdominal part of the aorta, pars abdominalis aortae.

Aorta(lat. aorta, Old Greek ἀορτή) - the largest unpaired arterial vessel large circle blood circulation. The aortic wall consists of three layers: intima(inner shell), middle shell(copper tunics) and adventitia.

Inner lining of the aorta includes the endothelium, the podendothelial layer and the elastic fiber plexus (as an internal elastic membrane). With age, the thickness of the intima increases.

The human aortic endothelium consists of flat endothelial cells located on the basement membrane. The podendothelial layer consists of a loose fine fibrillar connective tissue, rich in star-shaped cells. These cells, like cantilevers, support the endothelium. In the subendothelial layer, there are separate longitudinally directed smooth myocytes. A dense web of elastic fibers corresponds to the inner elastic membrane. The inner lining of the aorta at the point where it leaves the heart forms three pocket-like flaps - the so-called. " semilunar valves"- the only valves in the arteries. These formations are often called in the singular - the aortic valve.

Middle aortic membrane forms the main part of its wall, consists of several dozen elastic fenestrated membranes, which look like cylinders inserted into each other. They are interconnected by elastic fibers and form a single elastic frame together with the elastic elements of other shells.

Between the membranes of the middle lining of the aorta, there are smooth muscle cells, obliquely located in relation to the membranes, as well as fibroblasts.

Elliptic elastic membranes, elastic and collagen fibers, and smooth myocytes are immersed in an amorphous substance rich in glycosaminoglycans (GAGs). This structure of the middle membrane makes the aorta highly elastic and softens the jolts of blood ejected into the vessel during the contraction of the heart, and also ensures the maintenance of the tone of the vascular wall during diastole.

Outer sheath of the aorta relatively thin, does not contain an external elastic membrane. It is built of loose fibrous connective tissue with a large number of thick elastic and collagen fibers, mainly in the longitudinal direction. The outer shell protects the vessel from overstretching and rupture.

Rice. Schematic representation of the microscopic structure of the aortic wall: 1 - inner membrane (intima); 2 - middle shell (media); 3 - outer shell (adventitia).

The aorta is divided into three sections: ascending aorta, aortic arch and descending aorta, which in turn is divisible by chest and abdominal hour T and.

Ascending part of the aorta- this is the initial section of the aorta about 6 cm long, about 3 cm in diameter, located in the anterior mediastinum posterior to the pulmonary trunk. The ascending part of the aorta leaves the left ventricle of the heart behind the left edge of the sternum at the level of the third intercostal space; in the initial section, it has an extension - the aortic bulb (25-30 mm in diameter). At the location of the aortic valve, there are three sinuses on the inner side of the aorta. Each of them is located between the corresponding semilunar valve and the wall of the aorta. From the beginning of the ascending part of the aorta, the right and left coronary arteries depart. These arteries, together with the corresponding veins of the coronary sinus, form the cardiac (coronary), a circle of blood circulation that supplies the heart itself. The ascending part of the aorta lies behind and partly to the right of the pulmonary trunk, rises up and at the level of the junction of the second right costal cartilage with the sternum passes into the aortic arch (here its diameter decreases to 21-22 mm).

Aortic arch turns left and back from the back surface of costal cartilage 2 to the left side of the body of the 4 thoracic vertebra, where it goes into descending aorta... In this place there is a slight narrowing - the isthmus. The edges of the corresponding pleural sacs fit to the anterior semicircle of the aorta on its right and left sides. To the convex side of the aortic arch and to the initial sections of large vessels extending from it ( brachiocephalic trunk, left common carotid and subclavian arteries) adjacent to the front left brachiocephalic vein, and under the aortic arch begins right pulmonary artery, below and slightly to the left - pulmonary bifurcation... There is a bifurcation behind the aortic arch trachea... Between the bent semicircle of the aortic arch and the pulmonary trunk or the beginning of the left pulmonary artery there is arterial ligament... At this point, thin arteries branch off from the aortic arch to trachea and bronchus.

Rice. The aorta and its branches.

1 - thoracic part of the aorta; 2 - posterior intercostal arteries; 3 - celiac trunk; 4 - lumbar arteries; 5 - bifurcation (bifurcation) of the aorta; 6 - the median sacral artery; 7 - the right common iliac artery; 8 - the abdominal part of the aorta; 9 - inferior mesenteric artery; 10 - right testicular (ovarian) artery; 11 - right renal artery; 12 - superior mesenteric artery; 13 - the right lower phrenic artery; 14 - aortic bulb; 15 - the right coronary artery; 16 - the ascending part of the aorta; 17 - aortic arch; 18 - brachiocephalic trunk; 19 - left common carotid artery; 20 - left subclavian artery.

A - arteries extending from the ascending aorta and arch;

B - projections of the branches of the aorta on the surface of the body;

1 - left common carotid artery;
2 - left subclavian;
3 - aortic arch;
4 - the descending aorta;
5 - aortic bulb;
6 - left and
7 - right coronary arteries;
8 - ascending aorta;
9 - brachiocephalic trunk;
10 - right subclavian;
11 - the right common carotid artery;
12 - internal and
13 - external carotid arteries

Rice. Branches of the initial section and aortic arch

Descending part of the aorta (Pars descendens aortae)- this is the longest section of the aorta, lying in the posterior mediastinum, first to the left of the spinal column, then deviates somewhat to the right and passes from level 4 of the thoracic vertebra to 4 of the lumbar vertebra. At the XII level of the thoracic vertebra descending aorta passes through the aortic opening of the diaphragm and descends into the abdominal cavity.

Before the diaphragm descending aorta called thoracic aorta(pars thoracica aortae), and below the diaphragm - abdominal aorta(pars abdominalis aortae).

Thoracic aorta (aorta thoracalis) runs along the chest cavity in front of the spine. Its branches nourish the internal organs of this cavity, as well as the walls of the chest and abdominal cavities.

Abdominal aorta (aorta abdominalis) lies on the surface of the bodies of the lumbar vertebrae, behind the peritoneum, behind the pancreas, duodenum and mesenteric root small intestine... The aorta gives off large branches to the viscera in abdominal cavity... At level IV of the lumbar vertebra, it is divided into two common iliac arteries(a. iliaca communis), feeding the walls and viscera of the pelvis and lower limbs. From the place of division of the aorta (bifurcatio aortae) (bifurcation), as if continuing its trunk, a thin median sacral artery(a. sacralis mediana) .

Aortic arch, arcus aortae, is a continuation of the ascending intrapericardial aorta, aorta ascendens. The aortic arch begins at the level of attachment of the cartilage of the II rib to the left edge of the sternum. The highest point of the aortic arch is projected onto the center of the sternum handle. Large branches extend upward from the upper semicircle of the aortic arch behind the left brachiocephalic vein: the brachiocephalic trunk, the left common carotid and left subclavian arteries.

Start (right) and end (left) divisions aortic arch covered in front by the mediastinal parts of the parietal pleura and pleural costal-mediastinal sinuses. Above and partially in front of the aortic arch is the left brachiocephalic vein.

To the right of the start aortic arch the superior vena cava is located.

Middle aortic arch the front is covered with the remains of the thymus and fatty tissue with the brachiocephalic lymph nodes. The anterior surface of the arc on the left obliquely crosses the left vagus nerve, from which the left recurrent laryngeal nerve departs at the level of the lower edge of the arc, n. laryngeus recurrens, bending around the aortic arch from below and behind. Outside of the vagus nerve, on the anterior surface of the aortic arch, there is the left phrenic nerve and the accompanying vasa pericardiacophrenica.

On the front-lower surface of the aortic arch opposite the departure from its upper surface of the left subclavian artery is the place of attachment arterial ligament, lig. arteriosum, representing an obliterated arterial (botall *) duct. In the fetus, it connects the pulmonary trunk to the aorta. By the time the baby is born, the duct is usually overgrown, being replaced by an arterial ligament. In some children, such an infection does not occur, and a heart defect occurs - an unclosed Botallus duct.

The left phrenic nerve, which runs 1-2 cm anterior to arterial ligament... Botalls are also located here. lymph node arterial ligament.

Posterior surface of the aortic arch touches the anterior surface of the trachea, forming a slight depression on it. Slightly to the left, at the level of the transition of the aortic arch into the descending aorta, the esophagus is located behind it. Between the trachea and the esophagus behind the aortic arch lies the recurrent laryngeal nerve, and at the left edge of the esophagus - the ductus thoracicus.

Below and behind the aortic arch right goes right pulmonary artery towards the gate of the right lung.

Section of the aorta from the origin of the left subclavian artery to the transition to the descending aorta called the isthmus of the aorta. At this point, narrowing of the aorta, called coarctation, can occur. Most often, coarctation is congenital. With this defect, the lower half of the body is not sufficiently supplied with blood, and the branches of the aortic arch expand. Collateral blood flow occurs through the subclavian artery system. The main role in this is played by a. thoracica interna and the anterior intercostal arteries extending from it, as well as a. thoracica lateralis. Coarctation aorta is currently successfully eliminated by surgery.

Place of transition aortic arch into its descending section, it is projected on the left at the level of the IV thoracic vertebra. At this point, the aortic arch bends around the initial part of the left bronchus from front to back and from right to left.

V aortic arch circumference and below it are the aortic-cardiac nerve plexuses formed by the branches of both vagus nerves and both trunks of the sympathetic nerve.

The abdominal part of the aorta and its branches

Abdominal aorta located on the back wall of the abdominal cavity from the diaphragm to the level of the fifth lumbar vertebra, where the aorta is divided into the right and left common iliac arteries (Fig. 407). The parietal branches of the abdominal part of the aorta supply blood to the walls of the abdominal cavity, the visceral branches supply the internal organs. The parietal branches are paired inferior phrenic and lumbar arteries.

Lumbar arteries (aa. lumbales) depart from the aorta at the level of the lumbar vertebrae, go behind the legs of the diaphragm and the psoas major muscle, between the transverse and internal oblique muscles of the abdomen, give branches to them, and also dorsal ramus(r. dorsalis) to the muscles and skin of the back and spinal branch(r. spinalis) - to the spinal cord.

Inferior phrenic artery (aa.phrenica inferior) supplies blood to the diaphragm and the peritoneum covering it, gives superior adrenal arteries(aa. suprarenales superiores).

The visceral branches of the abdominal part of the aorta are subdivided into unpaired and paired. Among the unpaired branches, the celiac trunk, the superior and inferior mesenteric arteries are distinguished. Paired branches include the renal, middle adrenal, testicular (ovarian) arteries.

Celiac trunk(truncus coeliacus), a short vessel, departs from the aorta at the level of the 12th thoracic vertebra and is divided into the left gastric, common hepatic and splenic arteries (Fig. 408). Left gastric artery(a. gastrica sinistra) goes up and to the left, then turns to the right, goes along the lesser curvature of the stomach, anastomosing with the right gastric artery (from its own hepatic artery). Common hepatic artery(a. hepatica communis) goes to the right of the celiac trunk along the upper edge of the pancreas, enters the hepato-gastric ligament and divides into its own hepatic and gastro-duodenal arteries. Own hepatic artery(a. hepatica propria) goes to the liver in the thickness of the hepatoduodenal ligament, where it is divided into right and left branches. From the right branch to the gallbladder goes biliary artery(a. cystica). From the own hepatic artery to the lesser curvature of the stomach departs right gastric artery(a. gastrica dextra), anastomosed with the left gastric artery. Gastro-duodenal artery(a. gastroduodenalis) descends behind the pylorus of the stomach and is divided into the right gastroepiploic and posterior superior pancreatic duodenal arteries. Right gastroepiploic artery(a.gastroomentalis dextra) goes to the left along the greater curvature of the stomach, gives branches to the stomach and to the greater omentum and anastomoses with left gastroepiploic artery(from the splenic artery). Posterior superior pancreatic-duodenal artery(a. pancreaticoduodenalis superior posterior) goes between the head of the pancreas and the descending part of the duodenum, gives them the pancreatic and duodenal branches. Splenic artery(a. lienalis) goes to the spleen along the upper edge of the pancreas, gives the pancreas and short gastric arteries. Near the gate of the spleen from the splenic artery to the right and downward departs left gastroepiploic artery(a.gastroomentalis sinistra), which runs along the greater curvature of the ventricle, anastomoses with the right gastroepiploic artery and gives branches to the stomach and to the greater omentum.

The aorta is the largest vessel in the body, both in length and diameter, and in terms of blood flow, therefore the proper blood supply to all organs and systems of the body depends on it. The pathology of this largest artery in the human body negatively affects the work of all organs, the vessels to which branch off below the level of the lesion.

Aortic anatomy

Conventionally, this large vessel is divided into three parts, based on its direction:

• Upstream department.
• The aortic arch, the anatomy of which is considered separately.
• Descending part. This section is the longest. It ends when approaching the fourth lumbar vertebra. Here the common ones begin into which the abdominal aorta is divided.

Anatomy and topography

The ascending part of the aorta extends from the left ventricle. Having reached the second rib, it passes into the so-called arc, which, bending to the left, at the level of the fourth vertebra of the thoracic spine, passes into the descending part.

Anatomy of the aorta and the location of its departments and main branches relative to others internal organs at various levels has great importance when studying the structure of the chest and abdominal cavities.

Chest

Starting at the level of the fourth thoracic vertebra, the thoracic segment of the aorta is directed almost vertically downward, located in the region to the right of the aorta in this place, and the azygos vein; on the left - the parietal pleura.

Abdominal region

This section begins when the aortic vessel passes through the corresponding opening in the diaphragm and extends to the level of the fourth lumbar vertebra. In the abdominal cavity, the anatomy of the aorta has its own peculiarity: it lies in the retroperitoneal cellular space, on top of the lumbar vertebral bodies, surrounded by the following organs:

• to the right of it lies the inferior vena cava;
• from the front side, the posterior surface of the pancreas, the horizontal segment of the duodenum, and also part of the mesentery root of the small intestine are adjacent to the abdominal aorta.

Having reached the level, the abdominal aorta divides into two iliac arteries. They provide blood supply lower limbs(this place is called bifurcation, bifurcation of the aorta, and is its end).

In accordance with the location of the parts of this large vessel, the anatomy of the aorta and its branches is examined by division.

Ascending branches

This is the initial section of the vessel. Its duration is short: from the left ventricle of the heart to the cartilage of the second rib on the right.

At the very beginning of the ascending part of the aorta, the right and left areas of the blood supply of which are the heart branch off from it.

Branches of the aortic arch

The anatomy of the arch has the following feature: from its convex part, large arteries originate, carrying blood supply to the skull and upper limbs. The concave part gives off an insignificant size of branches that do not have a constant location.

The following branches extend from the convex side of the aortic arch (from right to left):

• brachiocephalic trunk ("brachiocephalic");
• left common carotid artery;
• left subclavicular artery.

The concave part of the arch gives off thin arterial vessels that fit the trachea and bronchi. Their number and location may vary.

Descending branches

The descending aorta, in turn, is divided into sections:

1. Thoracic, located above the diaphragm;
2. Abdominal, located below the diaphragm.

Chest section:

• Parietal arterial vessels for blood supply to the walls chest: the superior phrenic arteries, the branching surfaces of the diaphragm from the side of the chest cavity, and the posterior intercostal arterial vessels supplying blood to the intercostal and rectus abdominal muscles, the mammary gland, spinal cord, and soft tissue back.
• Visceral vessels extending from the thoracic region branch out in the organs of the posterior mediastinum.

Abdominal region:

• Parietal branches branching in the walls of the abdominal cavity (four pairs of lumbar arteries that supply blood to the muscles and skin of the lumbar region, abdominal walls, lumbar spine and spinal cord) and the lower surface of the diaphragm.
• Visceral arterial branches going to the abdominal organs are paired (to the adrenal glands, kidneys, ovaries and testicles; moreover, the names of the arteries correspond to the names of the organs supplied by them) and unpaired. The names of the visceral arteries correspond to the names of the organs supplied by them.

Vessel wall structure

The concept of "anatomy of the aorta" also includes the structure of the wall of this largest arterial vessel in the body. The structure of its wall has certain differences from the structure of the wall of all other arteries.

The structure of the aortic wall is as follows:

• Inner shell (intima). It is a basement membrane lined with endothelium. The endothelium actively reacts to signals received from the blood circulating in the vessel, transforms them and transfers them to the smooth muscle layer of the vascular wall.
• Middle shell. At the aorta, this layer consists of circularly located elastic fibers (unlike other arterial vessels in the body, where collagen, smooth muscle, and elastic fibers are represented - without a clear predominance of any of them). The anatomy of the aorta has a peculiarity: the middle sheath of the aortic wall is formed mainly by elastic fibers. The function of the middle shell is to maintain the shape of the vessel, and also provides its motility. The middle layer of the vascular wall is surrounded by interstitial substance (fluid), the main part of which penetrates here from the blood plasma.
• Adventitia (outer shell of the vessel). This connective tissue layer contains mainly perivascular fibroblasts. It is permeated with blood capillaries and contains a large number of endings of autonomic nerve fibers. The perivascular connective tissue layer is also a conductor of signals directed to the vessel, as well as impulses emanating from it.

Functionally, all layers of the vascular wall are interconnected and are able to transmit an information impulse to each other - both from the intima to the middle layer and adventitia, and in the opposite direction.