The aorta

Synonyms in a broader sense

Aorta, main artery, aorta, body aorta Medical: thoracic aorta, abdominal aorta English: aorta


The aorta is the largest blood vessel in the body and is also called the aorta. It is divided into four sections. With a total length of about 35 – 40 cm it has a diameter of 3 – 3.5 cm. It originates from the left heart.

Classification and sections

The aorta above the diaphragm (diaphragm) supplies the organs in the thorax and is divided into three sections: Below the diaphragm, this section is called the aorta abdominalis or more precisely the pars abdominalis descendens aortae. It gives off numerous branches to supply the abdominal organs. – ascending section (ascending aorta or pars ascendens aortae)

  • Arcus aortae
  • Descending section = Pars thoracica descendens aortae

The aorta emerges from the left heart directly behind the aortic valve.

For the most part, it still runs upwards in the pericardium. This ascending section is called the ascending aorta. It is about 5 – 6 cm long.

Directly behind the heart valve (aortic valve), the aorta also releases its first two branches. These are the left and right coronary arteries (also called coronary arteries) for supplying the heart muscle (arteria coronaria sinistra and arteria coronaria dextra). These two outlets lead to a distension of the aortic origin (bulbus aortae).

The ascending section extends to the first major vascular outlet, the brachiocephalic trunk. Where the ascending aorta begins, there is still a small section – the aortic root. It is only a few centimetres long and plays an important role in maintaining a continuous blood flow.

After that, it runs in an arc to the back, left and bottom. This aortic arch is also called Arcus aortae. It runs at the level of the 4th thoracic vertebra over the left main bronchus.

Large vessels for supplying the head, neck and arms emerge from the aortic arch. The truncus brachiocephalicus is the first to emerge and supplies the right side. The arteria thyroidea ima contributes to the blood supply of the thyroid gland.

The next two outlets are the arteria carotis communis sinistra, which supplies blood to the head and neck on the left side (=left carotid artery), and the arteria subclavia sinistra, which, as the left subclavian artery, continues on to the left arm. This topic might also be of interest to you: Arteries of the neckAfter the aortic arch, the main artery is called the descending thoracic aorta above the diaphragm and abdominalis below the diaphragm. The numerous branches supply the space between the ribs as intercostal arteries (11 arteriae intercostales posteriores and one arteria subcostalis), and the airways (bronchiales), the oesophagus, the pericardium (pericardium) and the mediastinum (a space behind the breastbone containing the thoracic organs without the lungs) as rami bronchiales, oesophageales, pericardiaci and mediastinales.

Before the aorta passes through the diaphragm at the level of the 12th thoracic vertebra, it makes two more upper branches on the right and left side to supply the diaphragm (arteria phrenica superior sinister and dexter)After the aorta has passed through the diaphragm, it immediately makes two more branches on the side to supply the lower diaphragm (arteria phrenica inferior sinister and dexter). Now follows as a large branch from the front the Truncus coeliacus. This large-calibre vessel soon divides into three sections to supply blood to the spleen (Arteria splenica), the liver (Arteria hepatica communis) and the stomach (Arteria gastrica sinistra).

The next organs to be supplied with blood are the adrenal glands (Arteria suprarenalis medialis sinistra and dextra). The superior mesenteric artery, which originates at the front, is divided into several branches and supplies the small intestine and large parts of the large intestine. The paired renal vessels (Arteria renalis sinster and dexter) descend above the unpaired Arteria mesenterica inferior, which supplies the remaining colon. Before the aorta divides into the iliac arteries (Arteria iliaca communis dexter and sinister) at the level of the 4th lumbar vertebra, a total of four paired, laterally emerging vessels carry blood to the lumbar region.