Venous blood from the lingual vein drains primarily into which vessel?

Correct answer: D. The internal jugular vein

• A. The pterygoid venous plexus lies in the infratemporal fossa around the lateral pterygoid and drains the maxillary region — clinically important as the site of PSA block hematoma and as a route of infection spread to the cavernous sinus.
• B. The external jugular vein is a superficial vessel formed by the posterior auricular and posterior division of the retromandibular vein. It drains the scalp and superficial face, not the tongue.
• C. The retromandibular vein forms within the parotid from the superficial temporal and maxillary veins. Its anterior division joins the facial vein and its posterior division helps form the external jugular — it is not the lingual drainage route.
• D. CORRECT. The LINGUAL VEIN drains directly into the INTERNAL JUGULAR VEIN, either on its own or after joining the common facial vein. The internal jugular is the principal deep venous channel of the head and neck, receiving the facial, lingual, pharyngeal and superior and middle thyroid veins before uniting with the subclavian vein to form the brachiocephalic vein.

Note: Clinical significance: this deep drainage of the tongue and floor of mouth into the internal jugular, together with the rich lymphatics, explains why floor-of-mouth infections (Ludwig angina) and tongue carcinomas spread rapidly and why bleeding from the lingual/sublingual arteries during mandibular implant placement is airway-threatening.