accessory hemiazygos vein
The accessory hemiazygos vein drains blood from the upper intercostal spaces.
Noun: A vein that is formed by the union of the fourth to seventh posterior intercostal veins on the left side of the body. It drains blood from the upper left intercostal spaces and typically empties into the azygos vein.
This is a specific anatomical term. It is used in medical, biological, and anatomical contexts to describe a particular blood vessel.
- During the dissection, the medical students identified the accessory hemiazygos vein coursing along the left side of the thoracic vertebrae.
- The imaging scan showed an anomaly where the accessory hemiazygos vein drained into the left brachiocephalic vein instead of the azygos vein.
- Blockage of the accessory hemiazygos vein can contribute to alternative venous drainage pathways in the chest.
- The term is often used in contrast to the hemiazygos vein, with which it may anastomose (connect). Together, these veins form part of the collateral circulation for the azygos system in the thorax.
- In anatomical descriptions, its relationship to other structures is key: "The accessory hemiazygos vein lies anterior to the vertebral bodies and receives blood from the upper left posterior intercostal veins."
- Hemiazygos vein (noun): A vein that drains the lower left posterior intercostal spaces and often connects with the accessory hemiazygos vein.
- Azygos vein (noun): The major unpaired vein on the right side of the body into which the accessory hemiazygos and hemiazygos veins often drain.
- Posterior intercostal veins (noun): The veins that drain the intercostal spaces and contribute to forming the accessory hemiazygos vein.
There are no direct common-language synonyms for this precise anatomical structure. In technical contexts, it may be referred to descriptively as: - The superior hemiazygos vein (a less common alternate name). - The left superior intercostal vein (though this can be a distinct but closely related vessel).
This term has a single, specific meaning in human anatomy. It does not have idiomatic or figurative uses. Its definition is consistent across standard anatomical references.
The accessory hemiazygos vein drains blood from the upper intercostal spaces.
- a vein formed by the union of the 4th to 7th posterior intercostal veins; empties into the azygos vein