External carotid artery, a. carotis externa, supplies blood to the outer parts of the head and neck, which is why it received the name of the external part, unlike the internal carotid artery, which penetrates the cavity of the skull. From the place of its origin, the external carotid artery rises upward, passes inwards from the posterior abdomen m. digastrici and m. stylohyoideus, pierces the parotid gland and behind the neck of the condylar process of the mandible, splits into its final branches.
The branches of the external carotid artery for the most part are remnants of arterial arcs and nourish organs arising from the gill arches. They go (number 9) as if along the radii of a circle corresponding to the head, and can be divided into three groups of three arteries in each — anterior, middle, and posterior groups, or triples.
The anterior group is caused by the development and location of the organs supplied by the arteries of this group and derived from the gill arches, namely: the thyroid gland and the larynx – a. thyroidea superior, tongue – a. lingualis and face – a. facialis.
1. A. thyroidea superior, the upper artery of the thyroid gland, which leaves the external carotid artery immediately above its beginning, goes down and forward to the thyroid gland, where it anastomoses with other thyroid arteries. Along the way gives a. laryngea superior, which together with n. laryngeus superior pierces lig. thyrohyoideum and supplies the branches of the muscles, ligaments and mucous membrane of the larynx.
2. A. lingualis, the lingual artery, departs at the level of the large horns of the hyoid bone, goes up through the Pirogov triangle, covered with m. hyoglossus, and goes to the tongue. Before joining, it gives branches to the hyoid bone, the palatine tonsils and the hyoid gland. Entering the tongue, the lingual artery trunk extends to the tip of the tongue called a. profunda linguae, which along the way gives multiple branches to the back of the tongue, rr. dorsales linguae.
3. A. facialis, the facial artery, departs somewhat higher than the previous one at the level of the angle of the mandible, runs medially from the posterior abdomen m. digastricus and reaches the leading edge m. masseter, where she bends over the edge of the jaw on the face. Here, ahead of m. masseter, it can be pressed to the lower jaw. Then it goes to the medial corner of the eye, where the end branch (a. Angularis) anastomoses with a. dorsalis nasi (a. ophthalmica branch from the system of the internal carotid artery). To bend through the lower jaw, it gives branches to nearby formations: to the pharynx and soft palate, to the tonsils, to the submandibular gland and the diaphragm of the mouth, to the salivary glands; after the bend – to the upper and lower lips.