Aorta

Topography of aortaAorta - the main arterial trunk large circulation (Fig. 1). The aorta is the elastic type arteries. The aortic wall is well supplied with blood vessels and nerves. In some places her nervous elements are extremely numerous; this is the so-called reflex zones, participating in the regulation of blood distribution. The aorta starts from the left ventricle of the heart onion aorta (about 3 cm in diameter). Here on the inside wall of the aorta have the aortic valve is determined by three semilunar valves (Fig. 2), and, accordingly, three bulging wall - aortic sinus, or sinuses Valsalva. In the right breast, there is a hole right coronary artery, in the left - the left coronary artery. The initial aorta - the ascending aorta - length 5-6 cm is located almost entirely within the pericardium (it is sometimes called Cardi-aorta). Lifting up, aorta behind the arm of the sternum makes a turn to the left in the form of the arc. On the border of the ascending aorta and the arc with age is formed oval expansion, due to the pressure of blood pumped out of the heart at the time of contraction of the left ventricle. This place can be a starting point of formation of a true aneurysms. From the aortic arch depart shoulder-head barrel, the left common carotid and left subclavian artery. Speaking through the left bronchus, the arch of the aorta at level IV of thoracic vertebra (aortic isthmus) enters the descending aorta. The descending aorta in the chest cavity lies in the posterior mediastinum the left of the spine, then moves to the right and goes through the aortic the aperture opening in the abdominal cavity situated in front of the spine and to the left of the lower hollow vein. At level IV of the lumbar vertebrae aorta gives the left and right common iliac artery.
The aortic valvethe length of the descending aorta about 30 cm, average diameter 2,5 see a Segment of the descending aorta, lying in the chest cavity, known as the thoracic aorta, in the abdominal cavity - abdominal aorta. From the thoracic aorta depart bronchial, esophageal, pericardial and mediastinal branches, top diaphragmatic, posterior intercostal occurring in the intercostal spaces (III to XI inclusive), and podreberie artery (under the twelfth ribs).
From the abdominal aorta depart vnutrennie and parietal branch. To unpaired vnutrennim branches are the celiac trunk, upper and lower mesenteric artery; to pair vnutrennim branches belong secondary adrenal, kidney, testicular (ovarian) artery; parietal branch - bottom diaphragmatic and lumbar arteries; the target branch - common iliac artery and median sacral arteryleading down into the pelvis.
Most often these anomalies of the aortic: congenital the narrowness of the aorta, the double arch of the aorta, right-hand art, cleft blood (botallowa) duct stenosis and atresia isthmus (coarctation of the aorta). In the latter case between proximal and distal segments of aortic circulation is supported by advanced collateral arteries. While there is increasing pressure in the vessels of the upper half of the body and the decrease in the vessels of the lower half.
Aortic disease - see aortic Aneurysm, Aortic, Atherosclerosis. Cm. also the Blood vessels.

The aorta (gr. aorte) - the main artery and the largest vessel of the human body (Fig. 1); getting out of the left ventricle of the heart.
The aorta is formed of paired embryonic vessels. The initial division of the ascending aorta is formed from the primary bulbus heart, the ascending aorta - from primary truncus arteriosus, arc - from primary IV Gill left the arteries, and a downward A. - from the left primary dorsal A. Nameless artery is formed of the right of primary ventral aorta.
There are the following departments of the aorta: ascending, arc, descending, abdominal.
Wall A. consists of three shells -1 inner, middle and outer. Inner sheath A. (tunica's intima) consists of a layer of endothelial cells turned into the lumen A., the subendothelial layer containing germ process cells Langhans, and inner elastic membrane (membrana elastica interna). The latter, in turn, consists of two pieces of elastic and collagen-o fibers with different beams. The average shell (tunica media) - durable elastic frame A. - consists of several dozens of rows of elastic fibers, intertwining in different directions, and bundles of smooth muscle fibers. Outer sheath (tunica adventitia) formed bundles of fibers.
The blood supply of the aortic wall performed by vasa vasorum of bronchial, intercostal arteries and vessels of fiber mediastinum. Venous outflow goes into the system and unpaired pronephros veins. Innerviruetsya A. from the system vagi (arc A.), sympathetic plexus (cervical vertebrae) and branches of spinal nerves. Nerve plexus, located in the aortic arch, plays an important role in regulating blood pressure.
Ascending aorta - the section from the exit of the ventricle to the discharge of the nameless artery - is behind the breast bone, top-III left rib cartilage to the right its edge. Front and is adjacent to the left pulmonary artery, front and right - eye right atrium; right - superior Vena cava; rear - left atrium. The caliber of the ascending aorta - up to 30 mm In primary her Department has three bulging corresponding semilunar valves - sinuses Valsalva (sinus Valsalvae). From the right and left sinuses originate coronary arteries (Fig. 1, a). Above there is an extension A. (bulbus aortae).
Arch of aorta - cut between places of discharge of the nameless and the left subclavian arteries. Is transversely from the bottom edge of the first rib cartilage right, front to back and left, going from the front to the rear of the mediastinum. Caliber arc - 21 - 22 mm, the place go into a downward A. arc has a narrowing of the isthmus (the isthmus aortae). Above the arc, closer to the front, lies the left nameless Vienna (v. anonyma sin.). On the front left side of the arc A. are left wandering and phrenic nerves. Return a branch of the vagus nerve covers arc A., passing in front from below ago. The arc is bent over the division of pulmonary artery and left main bronchus; from its lower surface of leaves to artery ligament (lig. arteriosum), which in embryo, it functions as the ductus arteriosus (ductus arteriosus). From the arc consistently leave nameless, left common carotid and left subclavian artery. The nature of their discharge (loose or trunk) rather variabelen. The height of standing of the arc also different depending on the body: in individuals with short and broad chest - higher astenikov, on the contrary,is lower. Anomalies of discharge of the main branches of the arc A. can cause compression of the trachea and esophagus.
The descending aorta starts from level ThIV, goes vertically down the left side of the spine, diaphragm several moves to the front. Front adjacent to it the root of the left lung, pericardium; the esophagus is on the right, and at the level of ThVIII-IX (near aortic to aperture) - in front of the descending A. on the Left descending A. covered mediastinal pleura; depart from it 10 pairs intercostal arteries, bronchial vessels, branch to the tissue of the mediastinum and the esophagus. The number of these vessels is impermanent.
Abdominal aorta begins after leaving aortic to aperture (ThXII) and ends at the level LIV bifurcation - by branching into two common iliac artery between which departs average vertebral artery. With age bifurcation is lowered by one to two vertebrae. Right from the abdominal A. lies the lower hollow vein, front - pancreas and the root of the mesentery. Parietal branches of the abdominal A. is lower diaphragmatic artery and lumbar branches (4 pairs), visceral - celiac artery, superior mesenteric, renal (two), the inferior mesenteric, the arteries of the adrenal glands and internal seed. When a loose type of bifurcation external and internal iliac artery may deviate separately.

Fig. 1. The aorta (front view): and - sinuses Valsalva. Fig. 2. Abnormal discharge the right subclavian artery from the aortic arch. Compression of the esophagus and trachea. Fig. 3-5. Coarctation of aorta and its surgical treatment. Fig. 6 and 7. Occlusion truncus brachiocephalicus and a. carotis communis and surgical treatment.