What is usually the first branch of the external carotid artery (ECA)?

The first branch of the external carotid artery (ECA) is typically the superior thyroid artery. This artery arises from the ECA just below the level of the hyoid bone and is responsible for supplying blood to the thyroid gland, as well as some surrounding structures such as the infrahyoid muscles and larynx.

Understanding the anatomy of the external carotid artery and its branches is fundamental in vascular ultrasound as it assists in identifying blood flow patterns and potential abnormalities in the neck. The superior thyroid artery's location and the fact that it branches off early from the ECA distinguishes it from other branches like the maxillary artery, facial artery, and occipital artery, which originate at different levels and serve different vascular territories.

This anatomical knowledge is crucial for healthcare professionals when performing ultrasound examinations or surgical interventions involving the neck region.