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

The first branch of the external carotid artery (ECA) is the superior thyroid artery. The external carotid artery ascends from the common carotid artery and supplies blood to the head and neck. The superior thyroid artery is the first major branch that arises from the ECA, typically located just above the bifurcation of the common carotid artery. It primarily supplies blood to the thyroid gland and areas close to it, including the larynx and infrahyoid muscles.

While other options are branches of the external carotid artery, they arise further along the artery's course. For instance, the facial artery arises after the superior thyroid artery and supplies the face, the lingual artery, which serves the tongue and floor of the mouth, also emerges after the superior thyroid artery, and the maxillary artery, which is a significant branch supplying the maxilla and mandible, is among the terminal branches of the external carotid. Understanding the correct order of branching is essential for understanding vascular anatomy and its clinical implications.