The aorta is the largest vessel in the human body that carries blood from the left ventricle and is the beginning of the systemic circulation.
There are several departments in the aorta:
- ascending (pars ascendens aortae) department;
- arch and branches of the aortic arch;
- descending (pars descendens aortae) section, which, in turn, is divided into the chest and abdominal parts.
Aortic arch and its branches
- Truncus brachiocephalicus branches off from the aortic arch at the level of the cartilage of the 2nd right rib. In front of it is the right brachiocephalic vein, and behind it is the trachea. After departing, the brachiocephalic trunk goes up and to the right, giving off two branches in the region of the right sternoclavicular joint: the right subclavian and the right common carotid artery.
- The common carotid artery (left) is one of the branches of the aortic arch. As a rule, this branch is 20-25 millimeters longer than the carotid common right artery. The path of the artery runs behind the scapular-hyoid and sternocleidomastoid muscles, then up the transverse processes of the cervical vertebrae. Outside of the vessel are the vagus nerve and the jugular (internal) vein;esophagus, trachea, pharynx, larynx, parathyroid and thyroid glands. In the area of the thyroid cartilage (its upper part), each of the common carotid arteries gives off the internal and external carotid arteries, which have approximately the same diameter. The place of division of the artery is called a bifurcation, in this place also lies the intersleepy glomerulus (carotid glomus, carotid gland) - an anatomical formation with dimensions of 1.5 x 2.5 mm, which is equipped with many chemoreceptors and a network of capillaries. There is a small dilatation at the origin of the external carotid artery called the carotid sinus.
- The external carotid artery is one of the two terminal branches of the common carotid artery. It branches off from the latter in the region of the carotid triangle (the upper edge of the thyroid cartilage). At first, it is located slightly medial to the carotid internal artery, and then lateral to it. The beginning of the carotid external artery lies under the sternocleidomastoid muscle, and in the region of the carotid triangle - under the subcutaneous muscle of the neck and the cervical fascia (its surface plate). Located inward from the digastric muscle (its posterior abdomen) and the stylohyoid muscle, the carotid (external) artery in the region of the neck of the mandibula (in the layer of the parotid gland) is divided into a pair of terminal branches: the maxillary and temporal superficial arteries. In addition, in its course, the carotid external atria gives rise to a number of branches: the anterior group - the facial, thyroid superior and lingual arteries, the posterior group - the posterior ear, occipital and sternocleidomastoid arteries, and the pharyngeal ascending artery departs towards the middle.
Branchesthoracic aorta
This segment, as already mentioned, is part of the descending aorta. It is located in the region of the posterior mediastinum, passing along the spinal column.
The branches of the thoracic aorta are presented in two groups: parietal and visceral (visceral).
Internal branches
The visceral branches of the aorta are represented by the following groups:
- Bronchial branches (2-4 pieces). They start from the anterior wall of the aorta in the region of the branch of the intercostal third arteries. Entering the gates of both lungs, they form an arterial intrabronchial network that supplies blood to the bronchi, connective tissue formations (framework) of the lungs, esophagus, pericardium, walls of pulmonary vessels (veins and arteries). In lung tissue, bronchial branches form anastomoses with branches of the pulmonary arteries.
- Esophageal branches (3-4 pieces). They have a length of about 1.5 cm and end in the walls of the esophagus (its thoracic segment). These branches start from the thoracic aorta in the region of 4-8 thoracic vertebrae. Anastomoses are formed with the upper phrenic, lower and upper thyroid, mediastinal arteries, as well as with the coronary left cardiac artery.
- The branches of the mediastinal (mediastenal) can have a varied placement, inconsistent. Often go as part of the pericardial branches. Carry out the blood supply to the tissue, lymph nodes of the posterior mediastinum and the wall (posterior) of the pericardium. Anastomoses are formed with the branches described above.
- Pericardial branches (1-2 pieces) thin and short. branch off from the frontaortic wall, supplying blood to the pericardium (its back wall). Anastomoses are formed with the mediastinal and esophageal arteries.
Wall branches
- The phrenic superior arteries, which branch off from the aorta, supply the pleura and the lumbar segment of the aorta with blood. They are combined into anastomoses with the diaphragmatic inferior, internal thoracic and intercostal inferior arteries.
- The posterior intercostal arteries (10 pairs) branch off from the posterior aortic wall and follow into the 3-11 intercostal spaces. The last pair passes under the 12th rib (that is, it is subcostal) and enters into an anastomosis with the lumbar arterial branches. The first and second intercostal spaces are supplied by the subclavian artery. The intercostal right arteries are slightly longer than the left ones and run under the pleura up to the costal angles, located posterior to the posterior mediastinum, lying on the anterior surfaces of the vertebral bodies. At the costal heads, dorsal branches depart from the intercostal arteries to the muscles and skin of the back, to the spinal cord (including its membranes) and spine. From the costal angles, the arteries run between the internal and external intercostal muscles, lying in the costal groove. The arteries in the region of the 8th intercostal space and below it lie under the corresponding rib, branch into lateral branches to the muscles and skin of the lateral parts of the chest, and then form anastomoses with the intercostal anterior branches from the thoracic (internal) artery. 4-6 intercostal arteries give branches to the mammary glands. The upper intercostal arteries supply blood to the chest, and the three lower arteries supply the diaphragm and abdominalwall (front). The third right intercostal artery gives off a branch that goes to the right bronchus, and branches depart from the 1-5th intercostal arteries that supply blood to the left bronchus. The 3rd-6th intercostal arteries give rise to the esophageal arteries.
Branches of the abdominal aorta
The abdominal segment of the aorta is a continuation of its thoracic part. It starts at the level of the 12th thoracic vertebra, passes through the aortic diaphragmatic opening and ends at the 4th lumbar vertebrae.
The abdominal region is located in front of the lumbar vertebrae, slightly to the left of the midline, lies retroperitoneally. To the right of it lies the vena cava (inferior) vein, in front - the pancreas, the horizontal segment of the duodenum and the mesenteric root of the small intestine.
Wall branches
The following parietal branches of the abdominal aorta are distinguished:
- The phrenic inferior arteries (right and left) branch from the abdominal aorta after it emerges from the aortic diaphragmatic opening and follow the diaphragm (its lower plane) forward, up and to the sides.
- Lumbar arteries (4 pieces) start from the aorta in the region of the upper 4 lumbar vertebrae, supply blood to the anterolateral surfaces of the abdomen, spinal cord and lower back.
- The sacral median artery departs from the aorta in the region of its division into the iliac common arteries (5th lumbar vertebra), follows the pelvic part of the sacrum, supplying the coccyx, sacrum and m. iliopsoas.
Visceral branches
The following visceral branches of the abdominalaorta:
- The celiac trunk originates from the aorta in the region of the 12th thoracic or 1st lumbar vertebrae, between the internal diaphragmatic crura. It is projected on the midline down from the xiphoid process (its apex). In the region of the body of the pancreas, the celiac trunk gives off three branches: the left gastric, common hepatic, and splenic arteries. Truncus coeliacus is surrounded by branches of the solar plexus and is covered in front by the parietal peritoneum.
- The middle adrenal artery is a steam room that branches off from the aorta just below the celiac trunk and supplies the adrenal gland.
- The superior mesenteric artery branches off from the aorta at the 1st lumbar vertebra, posterior to the pancreas. Then it passes through the duodenum (its anterior surface) and gives branches to the duodenum and pancreas, following between the sheets of the mesenteric root of the small intestine, gives branches for blood supply to the small and colon (right part) of the intestines.
- Renal arteries originate from the 1st lumbar vertebra. These arteries give rise to the inferior adrenal arteries.
- The arteries of the ovaries (testicles) depart just below the renal arteries. Passing posteriorly from the parietal peritoneum, the ureters are crossed, and then the iliac external arteries. In women, the ovarian arteries, through the ligament that suspends the ovary, go to the fallopian tubes and ovaries, and in men, as part of the spermatic cord through the inguinal canal, they go to the testicles.
- The inferior mesenteric artery branches off in the lower thirdabdominal aorta in the region of the 3rd lumbar vertebra. This artery supplies the colon (left side).
Atherosclerosis of the aorta
Atherosclerosis of the aorta and its branches is a pathology characterized by the growth of plaques in the lumen of the vessels, which subsequently leads to a narrowing of the lumen and the formation of blood clots.
The pathology is based on an imbalance in the ratio of lipid fractions, towards an increase in cholesterol, which is deposited in the form of aortic plaques and aortic branches.
Provoking factors are smoking, diabetes, heredity, physical inactivity.
Manifestations of atherosclerosis
Quite often, atherosclerosis occurs without obvious symptoms, which is associated with the large size of the aorta (as well as departments, branches of the aorta), developed muscle and elastic layers. The growth of plaques leads to heart overload, which is manifested by pressure surges, fatigue, increased heart rate.
With the progression of the pathology, the process extends to the branches of the aortic arch of the descending and ascending sections, including the arteries that feed the heart. In this case, the following symptoms occur: angina pectoris (retrosternal pain that radiates to the shoulder blade or arm, shortness of breath), indigestion and kidney function, jumps in blood pressure, cold extremities, dizziness, headaches, frequent fainting, weakness in the arms.
