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 a 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?
Accessory hemiazygos vein It joins the azygos vein behind the esophagus at the level of T8.
Where does the hemiazygos vein join the azygos vein?
What are the functions of the Azygos the hemiazygos and the accessory hemiazygos veins?
That is, the azygos vein serves to drain most of the posterior intercostal veins on the right side of the body, and the hemiazygos vein and the accessory hemiazygos vein drain most of the posterior intercostal veins on the left side of the body.
How is hemiazygos vein formed?
[1] The hemiazygos vein looks like the mirror image of the lower part of the azygos vein. It is formed by the union of left ascending lumbar vein and subcostal vein. It ascends to the level of the 8th thoracic vertebra and opens into the azygos vein.
What is the function of the hemiazygos and accessory Hemiazygos veins?
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 drains into the hemiazygos?
The hemiazygos vein runs in the posterior mediastinum and drains into the azygos vein at the level of the eighth thoracic vertebra….Hemiazygos vein.
| Drains from | Left lumbar ascending vein, subcostal vein |
|---|---|
| Drainage area | Posterior trunk muscles and skin, vertebral column, mediastinum, esophagus |
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 unusual 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 does azygos vein drain into?
superior vena cava
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. It passes through the diaphragm, reaches the mediastinum and finally drains into the superior vena cava.