Aorta. The aorta, aorta, represents the main trunk of the arteries of the great circle of blood circulation, carrying blood from the left ventricle of the heart.
Pars ascendens aortae begins with a significant expansion in the form of a bulb – bulbus aortae. From the inside, this expansion corresponds to the three sinuses of the aorta, sinus aortae, located between the aortic wall and the flaps of its valve. The length of the ascending aorta is about 6 cm.
Together with the truncus pulmonalis, behind which it lies, the aorta ascendens is still covered by the pericardium. Behind the handle of the sternum, it continues into the arcus aortae, which is bent back and to the left and spreads through the left bronchus at the very beginning, then passes at the level of the IV thoracic vertebra to the descending part of the aorta.
Pars descendens aortae lies in the posterior mediastinum, first to the left of the spinal column, then deviates somewhat to the right, so that when the diaphragm passes through the hiatus aorticus at the level of the XII thoracic vertebra, the aortic trunk lies in front of the spinal column in the middle line.
The descending part of the aorta to hiatus aorticus is called pars thoracica aortae, below being already in the abdominal cavity – pars abdominalis aortae. Here, at the level of the IV lumbar vertebra, it gives two large lateral branches (common iliac arteries) – bifurcatio aortae (split) and continues further into the pelvis in the form of a thin stem (a. Sacralis mediana).
When bleeding from the underlying arteries, the trunk of the abdominal aorta is pressed against the spinal column in the navel, which serves as a guideline for the level of the aorta, located above its bifurcation.