Arteries of the tongue

Topography of the lingual artery

The lingual artery is the second branch of the external carotid artery and originates at the level of the hyoid bone. In some cases, it may branch off as a common trunk together with the facial artery.

The vessel courses toward the deep surface of the hyoglossus muscle (m. hyoglossus). It enters the floor of the oral cavity strictly along the medial side of this muscle, lying medial to it. Further on, the vessel makes its way to the tip of the tongue, passing in the space between the genioglossus muscle (m. genioglossus) and the inferior longitudinal muscle (m. longitudinalis inferior). Topographically, the artery lies closer to the inferior surface of the tongue.

Main branches

During its course, the artery gives off several important branches that supply blood to various structures of the maxillofacial region:

• Sublingual artery (a. sublingualis) — supplies the tissues of the floor of the oral cavity and adjacent salivary glands.
• Deep lingual artery (a. profunda linguae) — a major branch running directly into the substance of the organ.
• Dorsal branches (rr. dorsales linguae) — numerous vessels distributed within the body of the tongue.

Note: the submental artery (a. submentalis) may also participate in the blood supply to this area, although it is frequently a branch of the facial artery.

Syntopy of vessels and nerves

The most important topographical landmark in this area is the hyoglossus muscle (m. hyoglossus). It acts as a dividing barrier between the neurovascular structures.

The lingual vein (v. lingualis) accompanies the artery initially, but then changes its position: together with the hypoglossal nerve (XII cranial nerve), it passes along the lateral side of the m. hyoglossus. Thus, the muscular mass reliably separates the vein and nerve, which lie superficially, from the artery, which is located deeply.

Pirogov's lymphoepithelial ring

The root of the tongue is richly supplied by dorsal branches and is the site of the lingual tonsil — an unpaired element of the Waldeyer-Pirogov ring. This ring is a collection of lymphoid tissue at the border of the respiratory and digestive tracts (at the entrance to the pharynx), providing primary immune defense.

Histoarchitectonics and immunogenesis of the tonsils

The structural basis of the tonsils is a mucous membrane fold beneath which lymphoid follicles are located. Their germinal centers are always oriented toward the crypt lumen. Surrounding the follicles is the parafimillary diffuse tissue, which is a T-dependent zone.

Lymphocytes, macrophages, and neutrophils constantly migrate into the epithelium above the follicles. As a result of physiological cell desquamation, crypt detritus is formed. The mechanism of immunogenesis is triggered when antigens are captured by antigen-presenting cells (macrophages, dendritic cells, and B lymphocytes). Following antigen processing and presentation in a complex with MHC, T helper cells are activated. This leads to the proliferation and differentiation of B cells into plasma cells, as well as the formation of memory cells.

Blood supply to the palatine tonsils: provided by branches of the facial, ascending pharyngeal, and descending palatine arteries. Venous drainage occurs into the facial or internal jugular vein, with the adventitia of the vessels fused tightly to the tonsillar capsule.

Clinical significance: The ring serves as a first-line barrier. Its inflammation and hypertrophy lead to tonsillitis, and the Waldeyer ring area is classified separately in the Ann Arbor lymphoma staging system.

Class and exam questions

What else to study on this topic

• Boundaries and contents of Pirogov's triangle
• Mechanisms of antigen-dependent lymphocyte differentiation
• Features of venous drainage from the palatine tonsils and the risk of hemorrhage
• Ann Arbor lymphoma classification and the role of Waldeyer's ring

Other topics in the "Anatomical Structures" section

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