V. jugularis interna, internal jugular vein, carries blood from the cranial cavity and organs of the neck; beginning in foramen jugulare, in which it forms an expansion, bulbus superior venae jugularis internae, the vein descends, lying lateral to a. carotis interna, and further down laterally from a. carotis communis. At the lower end of v. jugularis internae before connecting it with v. subclavia forms a second thickening – bulbus inferior v. jugularis internae; in the neck area above this bulge in the vein there is one or two valves. On its way to the neck, the internal jugular vein is covered by m. sternocleidomastoideus and m. omohyoideus.
Tributaries of the internal jugular vein are divided into intracranial and extracranial. The first are the sinuses of the dura mater of the brain, sinus durae matris, and the cerebral veins flowing into them ,, v. cerebri, veins of the cranial bones, vv. diploicae, veins of organ of hearing, vv. auditivae, orbital veins, v. ophtalmicae, and hard-shell veins, vv. meningeae. The latter include the veins of the external surface of the skull and the face, which flow into the internal jugular vein along its course.
There are connections between the intracranial and extracranial veins through so-called graduates, vv. emissariae passing through the corresponding openings in the cranial bones (foramen parietale, foramen mastoideum, canalis condylaris).
1. V. facialis, facial vein. Its tributaries correspond to ramifications a. facialis and carry blood from various face formations.
2. V. retromandibularis, mandibular vein, collects blood from the temporal region. Further down in v. retromandibularis flows into the trunk, carrying blood from the plexus pterygoideus (dense plexus between mm. pterygoidei), followed by v. Retromandibularis, passing through the thickness of the parotid gland together with the external carotid artery, below the angle of the mandible merges with v. facialis.
The shortest path connecting the facial vein with the pterygo plexus is the anatomical vein (v. Anastomotica facialis), which is located at the level of the alveolar margin of the mandible.
By combining the superficial and deep veins of the face, the anastomotic vein can become a way of spreading the infectious principle and therefore has practical significance.
There are also anastomoses of the facial vein with the orbital veins.
Thus, there are anastomotic connections between the intracranial and extracranial veins, as well as between the deep and superficial veins of the face. As a result, the multi-tiered venous system of the head and the connection between its various divisions are formed.
3. Vv. pharyngeae, pharyngeal veins, forming a plexus (plexus pharygneus) on the pharynx, infuse or directly into v. jugularis interna, or fall into v. facialis.
4. V. lingualis, the lingual vein, accompanies the artery of the same name.
5. Vv. thyroideae superiores, the superior thyroid veins, collect blood from the upper portions of the thyroid gland and the larynx.
6. V. thyroidea media, the middle thyroid vein, moves away from the lateral margin of the thyroid gland and merges into v. jugularis interna. At the lower edge of the thyroid gland there is an unpaired venous plexus, plexus thyroideus impar, outflow from which occurs through the vv. thyroideae superiores in v. jugularis interna, as well as v. thyroideae interiores and v. thyroidea ima in the veins of the anterior mediastinum.