The thyroidea ima ascends in front of the trachea

Vertebrate trachea

In tetrapod anatomy the trachea, or windpipe, is a tube that connects the pharynx or larynx to the lungs, allowing the passage of air. It is lined with pseudostratified ciliated columnar epithelium cells with goblet cells that produce mucus...

 to the lower part of the thyroid gland, which it supplies.

It varies greatly in size, and appears to compensate for deficiency or absence of one of the other thyroid vessels. The thyroidea ima artery, when present, arises from the brachiocephalic trunk (innominate artery).

It occasionally arises from the aorta

Aorta

The aorta is the largest artery in the body, originating from the left ventricle of the heart and extending down to the abdomen, where it branches off into two smaller arteries...

, the right common carotid, the subclavian

Subclavian artery

In human anatomy, the subclavian arteries are two major arteries of the upper thorax , below the clavicle . They receive blood from the top of the aorta...

 or the internal thoracic artery

Internal thoracic artery

In human anatomy, the internal thoracic artery , previously known as the internal mammary artery , is an artery that supplies the anterior chest wall and the breasts...

.

This artery is present in approximately 3-10% of the population and can cause problems for physicians when attempting a tracheostomy.

External links

• http://www.instantanatomy.net/thorax/vessels/aarchofaorta.html