The azygos vein is a unilateral vessel that ascends in the thorax to the right of the vertebral column, carrying deoxygenated blood from the posterior chest and abdominal walls. It forms part of the azygos venous system.
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 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.
Where does the azygos vein start?
The azygos vein originates at the junction of the right ascending lumbar and subcostal veins, entering the chest through the aortic hiatus. It ascends along the anterolateral surface of the thoracic vertebrae and arches ventrally to the right main bronchus at T5–T6, draining into the SVC.
What level does azygos vein?
The azygos vein is formed by the union of the ascending lumbar veins and right subcostal veins at around the T12-L2 vertebral level.
How many azygos veins are there?
Usually, there is a singular azygos vein on the right side of the body. However, the azygos vein is occasionally located in the midline or two independent veins may be present like in early embryonic development. The azygos vein usually originates at the level of the lumbar vertebrae, but may originate further up.
What is the longest vein in the body?
Great Saphenous Vein (GSV) – The GSV is the large superficial vein of the leg and the longest vein in the entire body. It can be found along the length of the lower limb, returning blood from the thigh, calf, and foot to the deep femoral vein at the femoral triangle. The femoral triangle is located in the upper thigh.
Is there only one azygos vein?
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.
Do horses have a left azygos vein?
A complete left cranial vena cava (LCVC) was found in a normal horse. … The azygous vein was normally distributed on the right side of the thoracic vertebral bodies but passed ventral to the aortic arch to empty into the cranial vena cava on the left close to the origin of the aortic arch.
What does the azygos vein drain dog?
The azygos vein is a vascular structure of extreme importance that drains blood from the posterior walls of the thorax and abdomen and unites the superior vena cava (SVC) to the inferior vena cava (IVC).
Where is the axillary vein?
Location. The axillary vein arises at the lower border of the axilla, just beneath the teres major shoulder muscle, near where the underarm meets the body.
What is SVC syndrome?
Superior vena cava syndrome (SVCS) is a group of problems caused when blood flow through the superior vena cava (SVC) is slowed down. The SVC is a large vein that drains blood away from the head, neck, arms, and upper chest and into the heart. SVCS is most often seen in people who have cancer.
Is there a left brachiocephalic vein?
The left brachiocephalic vein is formed posterior to the medial end of the left clavicle and descends diagonally to join the right brachiocephalic vein posterior to the right first costal cartilage. These veins become the superior vena cava.
Where do esophageal veins drain?
The esophageal veins drain blood from the esophagus to the azygos vein, in the thorax, and to the inferior thyroid vein in the neck. It also drains, although with less significance, to the hemiazygos vein, posterior intercostal vein and bronchial veins.
Which species have a right azygos vein?
Camelids differ from ruminants in having an azygous vein on the right side only.