Anatomy of the aorta

The aorta presents a dilatation at its origin in front of the aortic valves which is called bulb of the aorta. Its caliber is 25 mm then about 19 mm. The latter decreases after the origin of the renal arteries to measure about 14 mm.

The wall measures about 1.5 mm and has 3 layers or tunics (from the inside to the outside):

• Intima
• Media
• Adventine

Intrapericardial relationships:

• Forward: The right auricle
• Posteriorly: It is separated from the right pulmonary artery and the right atrium by the transverse sinus and the supra-arterial recess of the transverse sinus
• Right: The Lower Vault

Extrapericardial reports: 

• Forward: The thymus
• Laterally: Mediastinal pleura and lungs

At its origin, the ascending aorta gives the right and left coronary arteries.

The aortic arch is almost horizontal and is located at the level of the 4th thoracic vertebra (T4).

The aortic arch runs obliquely backwards and to the left. It has 2 concavities; one directed downward and the other to the right.

Top side:
From front to back, we find:

• The brachiocephalic trunk
• The left common carotid artery
• The left subclavian artery

In front of the left brachiocephalic vein passes

Bottom side: it answers to :

• The bifurcation of the pulmonary trunk
• The left main bronchus
• The cardiac ganglia

Antero-left side: from front to back, we find

• The phrenic nerve
• The upper cervical cardiac branches
• The vagus nerve
• The left superior intercostal vein runs along this side behind the phrenic nerve

It is uncovered by the left mediastinal pleura

Posterior-right side: from front to back, it crosses 

• The trachea
• The left upper tracheobronchial nodes
• The left recurrent laryngeal nerve
• The esophagus
• The thoracic duct

• Brachiocephalic trunk
• Thyroid artery ima (inconstant)
• Left common carotid artery
• Left subclavian artery

The thoracic aorta is located in the posterior mediastinum and follows the aortic arch at the inferior border of T4. It continues with the abdominal aorta at the inferior border of T12 through the aortic hiatus of the diaphragm.

Forward:

• Left pulmonary root and ligament
• Left vagus nerve, top
• Aortico-esophageal pleural recess, below

Back:

• Thoracic spine
• Accessory hemi azygos vein
• Left great splanchnic nerve

Left: Left mediastinal pleura

Right:

• Lateral aspect of the thoracic spine
• Esophagus, top
• Thoracic duct
• Azygos vein, below

• Right and left bronchial arteries
• Pericardial branches
• Esophageal branches
• Mediastinal branches
• The superior phrenic arteries
• Posterior intercostal arteries

It is the terminal part of the descending aorta. It is located in the abdominal cavity.

It originates at the level of the aortic hiatus, opposite the lower border of the body of T12.
Located in the medial retroperitoneal space, it descends downward to the left of the midline to L4. It then terminates in 3 branches: the right and left common iliac arteries and the median sacral artery.

In the aortic hiatus: The thoracic duct (posteriorly) and sometimes the medial root of the hemi-azygos vein.

In the abdomen: it is accompanied throughout its course by lumbar lymph nodes.

• Forward From top to bottom, we find
  • The Omentary Scholarship
  • The body of the pancreas
  • The horizontal portion of the duodenum
  • Hollow coves
• Back: Lumbar vertebrae L1 to L4
• On the right :
  • Chlorine tank
  • Thoracic duct
  • Right celiac ganglion
  • Azygos vein
  • Inferior vena cava
  • Right pillar of the diaphragm
• On the left : 
  • Left pillar of the diaphragm
  • Left celiac ganglion
  • Duodeno-jejunal angle
  • Sympathetic trunk

• Common iliac arteries
• Medial sacral artery

Marie Messager
Osteopath in Versailles
78 - Yvelines