Definition

1. Noun:
   • A major vein in the thoracic region: The vena azygos is one of the principal veins that drains blood from the thoracic and abdominal walls. It is part of a system that provides an alternative pathway for blood to return to the heart if the main veins are blocked.
   • Anatomical structure: Specifically, it originates as an upward continuation of the right ascending lumbar vein and ultimately empties into the superior vena cava, which carries blood to the heart's right atrium.

Usage Examples

• Noun:
  • The surgeon carefully avoided the vena azygos during the procedure.
  • An obstruction in the vena azygos can lead to the development of collateral circulation.

Advanced Usage

• "Azygos system": Refers to the collective network of veins, including the vena azygos, hemiazygos, and accessory hemiazygos veins, which drain the posterior walls of the thorax and abdomen.
  • The azygos system provides a crucial venous bypass route.

Variants and Related Words

• Azygos vein: A direct synonym for vena azygos.
• Hemiazygos vein (n): A vein on the left side of the body, often connecting to the vena azygos, that drains the lower left posterior intercostal spaces.
• Accessory hemiazygos vein (n): A vein on the left side that drains the upper left posterior intercostal spaces and typically joins the vena azygos or hemiazygos vein.

Synonyms

• Azygos vein: The most common alternative term.
• Azygous vein: A less common variant spelling.

Related Anatomical Terms (Not Phrasal Verbs or Idioms)

Given the technical nature of this term, standard phrasal verbs and idioms do not apply. However, it is closely associated with other anatomical structures. - Superior vena cava: The large vein into which the vena azygos terminates. - Ascending lumbar vein: The vein from which the vena azygos often arises.

Noun

1. one of a system of veins that drain the thoracic and abdominal walls; arises as a continuation of the right ascending lumbar vein and terminates in the superior vena cava