Lingual artery

The lingual artery  arises from the external carotid between the superior thyroid and external maxillary; it first runs obliquely upward and medialward to the greater cornu of the hyoid bone; it then curves downward and forward, forming a loop which is crossed by the hypoglossal nerve, and passing beneath the Digastricus and Stylohyoideus it runs horizontally forward, beneath the Hyoglossus, and finally, ascending almost perpendicularly to the tongue, turns forward on its lower surface as far as the tip, under the name of the profunda linguæ.

Its first, or oblique, portion is superficial, and is contained within the carotid triangle; it rests upon the Constrictor pharyngis medius, and is covered by the Platysma and the fascia of the neck. Its second, or curved, portion also lies upon the Constrictor pharyngis medius, being covered at first by the tendon of the Digastricus and by the Stylohyoideus, and afterward by the Hyoglossus. Its third, or horizontal, portion lies between the Hyoglossus and Genioglossus. The fourth, or terminal part, under the name of the profunda linguæ runs along the under surface of the tongue to its tip; here it is superficial, being covered only by the mucous membrane; above it is the Longitudinalis inferior, and on the medial side the Genioglossus. The hypoglossal nerve crosses the first part of the lingual artery, but is separated from the second part by the Hyoglossus.

The branches of the lingual artery are:

• The suprahyoid branch of the lingual artery runs along the upper border of the hyoid bone, supplying oxygenated blood to the muscles attached to it and anastomosing with its fellow of the opposite side.
• The Sublingual Artery arises at the anterior margin of the Hyoglossus, and runs forward between the Genioglossus and Mylohyoideus to the sublingual gland. It supplies the gland and gives branches to the Mylohyoideus and neighboring muscles, and to the mucous membrane of the mouth and gums. One branch runs behind the alveolar process of the mandible in the substance of the gum to anastomose with a similar artery from the other side; another pierces the Mylohyoideus and anastomoses with the submental branch of the facial artery.
• The dorsal lingual branches of lingual artery consist usually of two or three small branches which arise beneath the Hyoglossus. They ascend to the back part of the dorsum of the tongue, and supply the mucous membrane in this situation, the glossopalatine arch, the tonsil, soft palate, and epiglottis; anastomosing with the vessels of the opposite side.
• The deep lingual artery (or ranine artery) is the terminal portion of the lingual artery after the sublingual artery is given off. It travels superiorly in a tortuous course along the under (ventral) surface of the tongue, below the Longitudinalis inferior, and above the mucous membrane. It lies on the lateral side of the Genioglossus, the main large extrinsic tongue muscle, accompanied by the lingual nerve. However, the deep lingual artery passes inferior to the hyoglossus  while the lingual nerve passes superior to it (for a comparison, the hypoglossal nerve, passes superior to the hyoglossus).