Synonyms
vena cava : vena cava
Definition
The vena cava (vena cava) is a large blood vessel that has the task of collecting blood in the body and returning it to the heart. It is divided into an upper and a lower part. The vena cava opens into the right atrium.
Classification
The vena cava is divided into two sections:
- Superior vena cava (vena cava superior)
- Inferior vena cava (inferior vena cava)
The superior vena cava runs in the thorax to the right of the midline along the right edge of the sternum. It is formed at the level of the 1st rib (ribs) by the confluence of the veins that carry the oxygen-poor blood from the arms, head and neck. It borders from behind on the right main bronchus (lung) of the respiratory tract.
Furthermore, the vena azygos opens into the superior vena cava at the level of the 3rd rib. This is a venous system at the rear wall of the thorax, which drains the blood of the esophagus, pericardium, upper diaphragm and bronchi. The vena azygos is joined by the vena hemiazygos. Both are cavocaval anastomoses. This means that they connect the inferior and superior vena cava with each other and can be regarded as a bypass circuit in case of a blood flow disturbance of the vena cava.
Anatomy of the inferior vena cava and its tributaries
The inferior vena cava is the result of the confluence of the two iliac veins. It runs upwards from the 5th lumbar vertebra (lumbar spine) to the right of the aorta. Blood flows from the unpaired abdominal organs (e.g. intestine) via the portal vein (vena porta) and thus via the liver and only then shortly before passing through the diaphragm into the inferior vena cava.
The venous blood of the remaining pelvic and abdominal organs flows directly through the inferior vena cava. After passing through the diaphragmatic hole (Foramen venae cavae), it continues for about 1 cm in the thorax and then flows into the right atrium together with the superior vena cava. The direct influxes are the lower diaphragmatic veins (inferior phrenic veins), lumbar veins (lumbar veins), hepatic veins (hepatic veins), renal veins (renal veins) and the testicles or ovaries (testicular vein or ovary).
