What is unique about the azygos vein?
Azygos vein is the vein that drains the venous blood from the upper part of the posterior abdominal wall and the thoracic wall. It is very important for the reason that it connects the superior vena cava with the inferior vena cava, and it has very few to no valves.
What is the difference between azygos and hemiazygos veins?
Thus, azygos means unpaired. The azygos vein is unpaired in that there is only one in the body, mostly on the right side. While there is the hemiazygos vein and its accessory on the left side of the body, they are considered tributaries of the azygos vein rather than its left-side equivalent.
What is hemiazygos vein?
The hemiazygos vein arises from the left ascending lumbar vein. It drains the lower left posterior intercostal veins and ascends on the vertebral bodies posterolateral to the descending aorta. At T8, it crosses to the right behind the aorta, thoracic duct, and esophagus, and joins the azygos vein.
What level does hemiazygos drain into azygos?
The azygos vein usually arises either from the lumbar azygos vein or from the posterior side of inferior vena cava around the level of renal veins….Azygos vein.
| Origin | Lumbar azygos vein/ inferior vena cava |
|---|---|
| Tributaries | Hemiazygos vein, accessory hemiazygos vein |
| Drains to | Superior vena cava |
What does the Hemiazygos vein drain into?
The azygos vein drains into the superior vena cava. At approximately T8–T9 the hemiazygos veins join the azygos vein usually posterior to the aorta. The accessory hemiazygos joins the azygos at T7–T8 crossing posterior to the aorta [1].
What is the function of the azygos vein?
It is responsible for draining the thoracic wall and upper lumbar region via the lumbar veins and posterior intercostal veins 1. It also provides important collateral circulation between the superior and inferior venae cavae should they become obstructed 2.
What does the hemiazygos vein drain into?
Where does hemiazygos vein terminate?
The accessory hemiazygos vein usually crosses the midline and terminates by draining into the azygos vein at the level of the T7 vertebra.
What is the function of the Hemiazygos and accessory Hemiazygos veins?
The accessory hemiazygos vein drains the superior left hemithorax. It arises from the 4th to 8th left posterior intercostal veins and lies longitudinally on the left side of the vertebral bodies. It also drains the left bronchial vein and some veins from the oesophagus.
What is the function of the hemiazygos and accessory hemiazygos veins?
Are there any normal variants of the accessory hemiazygos vein?
Normal variants of the accessory hemiazygos vein This short communication describes two normal variants of the accessory hemiazygous vein in a 15-year-old female. The article demonstrates that knowledge of the aberrant venous anatomy and the collateral pathway is important for the practising radiologist.
Where is the hemiazygos vein located in the body?
Hemiazygos vein. The hemiazygos vein (vena azygos minor inferior) is a vein running superiorly in the lower thoracic region, just to the left side of the vertebral column. Contents. Structure. The hemiazygos vein and the accessory hemiazygos vein, when taken together, essentially serve as the left-sided equivalent of the azygos vein.
Which is the left equivalent of the azygos vein?
Hemiazygos vein (Vena hemiazygos) The hemiazygos vein (also known as the inferior hemiazygos vein) arises from the confluence of left lumbar ascending and subcostal veins. It is considered to be a left equivalent of the azygos vein.
Where does the hemiazygos vein drain During cannulation?
Structure. In the case of hemiazygos continuation of the IVC, the hepatic veins can drain directly into the right atrium (3, 10). An incidental finding of this condition during venous cannulation for cardiopulmonary bypass complicates the procedure, since no solid IVC trunk for placing the cannula is present.