Lingual septum

Structure of the muscular framework and septum

The tongue is a muscular organ covered by a mucous membrane. Its main structural feature is the presence of a longitudinal septum composed of dense connective tissue. This structure runs strictly along the midline, dividing the organ into two symmetrical halves. The external landmark of the septum is the sulcus of the tongue, located on its dorsal surface.

The base of the organ around the septum is formed by bundles of striated muscle fibers. They intertwine in three mutually perpendicular directions, and their ends insert into the lamina propria of the mucous membrane. The spaces between the muscle bundles are filled with layers of loose connective tissue containing blood vessels, nerve fibers, and fat lobules. Anatomically, the organ is divided into three parts: the root, body, and tip.

Histological features of the surfaces

The structure of the lingual membranes directly depends on their function and contact with food. The septum and muscular framework are covered by mucosa, which has different structures in different areas:

• Inferior surface. Consists of three layers: non-keratinized stratified squamous epithelium, lamina propria (with low papillae), and submucosa. The presence of the submucosa is responsible for the high mobility of the mucosa in this area.
• Superior surface (dorsum) and lateral surfaces. Here, the submucosa is absent, so the lamina propria is firmly fused with the muscle tissue. The epithelium in these areas is stratified squamous, partially keratinized. The lamina propria extends into the epithelial layer, forming lingual papillae (their basis consists of primary and secondary connective tissue papillae).

Involvement of the tongue in swallowing and respiration

The muscular apparatus of the tongue, divided by the septum, plays a key role in the mechanical processing of food, taste perception, speech production, and the protection of the airways.

• Act of swallowing. This is a reflex process (the regulation center is located in the floor of the fourth ventricle). During swallowing, the extrinsic muscles of the larynx pull it toward the root of the tongue. In turn, the root of the tongue moves posteriorly and tightly presses the epiglottis against the narrowed laryngeal inlet, completely sealing off the airways. The food bolus bypasses the larynx laterally and is pushed into the esophagus.
• Respiratory function. During normal quiet nasal breathing, the soft palate hangs freely downward and touches the root of the tongue, completely separating the oral cavity from the pharynx. If nasal patency is impaired (e.g., due to polyps, adenoids, or a deviated nasal septum), the tongue flattens and drops, opening the pathway for airflow through the mouth. Relaxation of the muscles of the tongue, pharynx, and soft palate during sleep is the main cause of snoring.

Clinical anatomy and pathology

The tissues of the tongue may be involved in various systemic and traumatic processes that require the clinician's attention:

• Sarcoidosis. A rare localization of the pathology (occurring in less than 1% of cases). In the oral cavity, it manifests as swelling and ulceration of the mucous membrane of the tongue, lips, and gums. Oropharyngeal sarcoidosis can cause obstructive sleep apnea (sometimes being the sole manifestation of the disease).
• Osler-Weber-Rendu syndrome. Hereditary weakness of small arterioles, where the vessel wall in certain areas consists only of endothelium. Bright red, club-like dilations—telangiectasias—form on the lateral surfaces and the tip of the tongue. They are extremely fragile and easily traumatized, causing recurrent bleeding that eventually leads to pronounced anemia.
• Wounds. Combat (gunshot) neck injuries are often complex and accompanied by wounds of the tongue and mandible. With concomitant damage to the airway, dysphagia is accompanied by respiratory impairment and profuse salivation.

Class and exam questions

What else to study on this topic

• Mechanisms of reflex airway protection during swallowing
• Sarcoidosis of the ENT organs and oral cavity: endoscopic presentation
• Hereditary hemorrhagic telangiectasias (Osler-Weber-Rendu syndrome)
• Gunshot and domestic wounds of the neck and pharynx
• Etiology and predisposing factors of snoring

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.