Lingual artery

The lingual artery is a branch of the external carotid artery that primarily supplies blood to the tongue and the floor of the mouth. It plays an essential role in the vascularization of the oral cavity.

Location

The lingual artery arises from the external carotid artery, usually at the level of the hyoid bone, just above or near the origin of the superior thyroid artery. It runs deep to the muscles of the tongue and the floor of the mouth, passing medially toward the tongue. The artery passes beneath the hyoglossus muscle, following a course that closely corresponds with the muscles of the tongue, eventually branching to supply various parts of the oral cavity, including the tongue, sublingual glands, and the mucous membrane of the floor of the mouth.

Structure and Anatomy

Origin

The lingual artery arises from the external carotid artery, typically near the level of the hyoid bone, just above the origin of the superior thyroid artery. It is usually the second branch of the external carotid artery, following the superior thyroid artery. The point of origin can vary slightly, but it is generally consistent in its emergence below the mandibular angle, within the carotid triangle of the neck.

Course

After its origin, the lingual artery runs an oblique course, initially moving forward and upward along the side of the neck. It travels toward the floor of the mouth, passing deep to the posterior belly of the digastric muscle and the stylohyoid muscle. The artery then passes beneath the hyoglossus muscle, one of the muscles of the tongue, to enter the oral cavity.

As it enters the mouth, the artery is positioned between the hyoglossus muscle (laterally) and the middle pharyngeal constrictor (medially), following a path that closely adheres to the muscles of the tongue. The artery continues its course toward the tongue, where it divides into several important branches.

Branches

The lingual artery gives off several branches along its course that supply the tongue, floor of the mouth, and adjacent structures. The major branches of the lingual artery include:

• Suprahyoid Branch: This small branch runs along the superior border of the hyoid bone, supplying the muscles and tissues near the hyoid bone, particularly the suprahyoid muscles that aid in swallowing and tongue movements.
• Dorsal Lingual Arteries: These branches arise from the lingual artery near the posterior part of the tongue. They supply the posterior part of the tongue, including the dorsum (top surface), the mucous membranes, and the lingual tonsils. These arteries also send small branches to the epiglottis, the soft palate, and the mucous membranes of the posterior oral cavity.
• Sublingual Artery: This artery arises from the lingual artery as it passes beneath the hyoglossus muscle and runs forward between the mylohyoid and genioglossus muscles. The sublingual artery supplies the sublingual gland, the mucous membranes of the floor of the mouth, and the surrounding soft tissues. It also anastomoses with the submental artery, a branch of the facial artery.
• Deep Lingual Artery (Ramus Profundus Linguae): The terminal branch of the lingual artery, the deep lingual artery runs along the ventral (underside) of the tongue. It extends toward the tip of the tongue, following its length and providing blood to the intrinsic muscles of the tongue and the mucous membranes along the tongue’s inferior surface. The deep lingual artery is often palpable on the underside of the tongue as it is relatively superficial in this region.

Termination

The lingual artery terminates as the deep lingual artery, which extends toward the apex (tip) of the tongue, supplying the tongue’s intrinsic muscles, mucous membranes, and surface tissues. The artery anastomoses with the contralateral deep lingual artery on the opposite side of the tongue, ensuring an adequate blood supply to the tongue from both sides.

Relationships with Surrounding Structures

As it courses through the neck and oral cavity, the lingual artery is closely related to several key anatomical structures:

• Hyoglossus Muscle: The lingual artery runs deep to the hyoglossus muscle after it passes into the oral cavity. The hyoglossus is one of the muscles responsible for depressing and retracting the tongue, and the artery’s relationship to this muscle helps it reach the tongue’s internal structures.
• Hypoglossal Nerve (CN XII): The hypoglossal nerve, which supplies motor innervation to the muscles of the tongue, crosses laterally to the lingual artery. The nerve lies on the external surface of the hyoglossus muscle, while the artery passes deep to the muscle. This anatomical relationship is important in surgeries involving the tongue, as the nerve and artery run in close proximity.
• Mylohyoid Muscle: The sublingual branch of the lingual artery courses along the inferior surface of the mylohyoid muscle to supply the floor of the mouth, sublingual gland, and mucous membranes. The mylohyoid muscle forms the muscular floor of the oral cavity, and the artery’s branches run in the connective tissue just above this muscle.
• Facial Artery: The sublingual artery, one of the branches of the lingual artery, anastomoses with the submental artery, which is a branch of the facial artery. This connection contributes to the extensive collateral circulation in the region of the mouth and tongue.

Anastomoses

The lingual artery forms important anastomotic connections with nearby arteries, ensuring that the oral cavity and tongue receive a robust blood supply. Some of these key anastomoses include:

• Contralateral Lingual Artery: The deep lingual artery anastomoses with its counterpart on the opposite side of the tongue, providing bilateral blood supply to the tongue’s muscles and tissues.
• Facial Artery: The sublingual artery anastomoses with the submental branch of the facial artery, forming a connection that supplies the floor of the mouth and surrounding structures.
• Tonsillar Branches of the Facial Artery: The lingual artery also anastomoses with branches of the facial artery that supply the tonsillar region and the pharynx.

Variations

The lingual artery can demonstrate anatomical variations in its origin and course. In some individuals, the lingual artery may share a common trunk with the facial artery, known as the linguofacial trunk. Additionally, the course of the lingual artery, particularly its branching pattern within the oral cavity, can vary between individuals. These variations are important considerations during surgeries in the region of the neck and mouth, such as during glossectomies or sublingual gland surgeries.

Surrounding Vascular Structures

As it courses through the neck and oral cavity, the lingual artery is located near several other important vascular structures, including:

• External Carotid Artery: The lingual artery arises from the external carotid artery near its origin, typically following the superior thyroid artery.
• Facial Artery: The facial artery runs superficially in the face but forms anastomoses with the lingual artery, particularly through the submental and tonsillar branches.
• Inferior Alveolar Artery: The lingual artery is located near the inferior alveolar artery, a branch of the maxillary artery that supplies the teeth and mandible. Although they follow separate courses, their proximity is important for ensuring blood supply to the lower jaw and oral cavity.

Relations with the Tongue and Floor of the Mouth

The lingual artery’s deep course along the hyoglossus muscle and its branches to the dorsum and underside of the tongue make it the main arterial supply to the tongue and surrounding soft tissues. Its branches also supply the sublingual gland and the floor of the mouth, which are essential for salivary production and oral mucosa health.

Function

Blood Supply to the Tongue

The primary function of the lingual artery is to provide oxygenated blood to the tongue, which is crucial for its movement, sensation, and functionality. The artery delivers blood to both the intrinsic and extrinsic muscles of the tongue through its deep lingual and dorsal lingual branches. These muscles are responsible for various tongue movements, including speaking, chewing, swallowing, and manipulating food. The blood flow from the lingual artery ensures that the tongue remains healthy, well-nourished, and capable of performing these essential tasks.

Blood Supply to the Mucous Membranes of the Mouth

The lingual artery also plays an important role in vascularizing the mucous membranes of the floor of the mouth, through its sublingual branch. This supply is essential for maintaining the health of the oral mucosa, which protects underlying tissues and facilitates various oral functions, including moisture retention, taste sensation, and speech. By ensuring the mucous membranes are well-nourished, the lingual artery supports a healthy oral environment and effective healing in cases of injury or trauma.

Blood Supply to the Sublingual Gland

Another key function of the lingual artery is to provide blood to the sublingual gland, the smallest of the three major salivary glands. The sublingual artery, a branch of the lingual artery, supplies this gland, ensuring that it receives enough oxygen and nutrients to maintain its function in saliva production. Saliva plays a vital role in digestion, oral hygiene, and maintaining the balance of bacteria in the mouth. Without an adequate blood supply, the sublingual gland would not function optimally, leading to decreased saliva production and potential oral health issues.

Blood Supply to the Dorsum and Underside of the Tongue

The lingual artery supplies the dorsum (upper surface) and ventral (underside) surfaces of the tongue via its dorsal lingual arteries and deep lingual artery, respectively. These areas are critical for both taste sensation and the overall function of the tongue. The dorsal lingual branches nourish the posterior part of the tongue, including the lingual tonsils, while the deep lingual artery supplies the muscles and tissues at the tip and lower surface of the tongue. The tongue’s intricate network of taste buds, particularly on the dorsal surface, depends on a reliable blood flow to maintain sensory function.

Support for Speech and Swallowing

The lingual artery ensures that the muscles of the tongue receive an adequate supply of oxygenated blood, allowing the tongue to perform its complex roles in speech and swallowing. Speech requires precise movements of the tongue to articulate sounds and form words, while swallowing involves coordinated movements that help propel food into the esophagus. Blood flow from the lingual artery is critical for maintaining the muscular function needed for these activities. By supplying the intrinsic and extrinsic muscles of the tongue, the artery supports efficient speech production and the swallowing process.

Nutrient Delivery and Waste Removal

As with all arteries, the lingual artery plays an essential role in delivering oxygen, glucose, and other nutrients to the tissues it supplies. This nutrient delivery is crucial for the maintenance and function of the tongue’s muscles, the mucosa of the mouth, and the sublingual gland. In turn, the blood flow from the lingual artery also facilitates the removal of metabolic waste products, such as carbon dioxide and lactic acid, from these tissues. Efficient nutrient exchange ensures the optimal function and longevity of the tongue and oral structures.

Support for Taste Sensation

Taste sensation is an important function of the lingual artery. The artery’s dorsal lingual branches supply the taste buds on the posterior part of the tongue, including the circumvallate papillae and foliate papillae, which are responsible for detecting various taste modalities like sweet, salty, sour, bitter, and umami. By maintaining the health of the taste buds and ensuring they receive a steady blood supply, the lingual artery supports the tongue’s ability to perceive and differentiate tastes, contributing to the sensory experience of eating.

Blood Supply to the Floor of the Mouth

The sublingual artery, a branch of the lingual artery, is the major supplier of blood to the floor of the mouth. This area includes important structures such as the mylohyoid muscle, mucosa, and sublingual glands. By providing blood to this region, the lingual artery ensures the tissues and glands in the floor of the mouth remain healthy and functional. This blood supply is critical for maintaining oral health, especially in the soft tissues of the floor of the mouth, which are prone to injury and infection.

Thermoregulation

The lingual artery contributes to the thermoregulation of the tongue and oral cavity by adjusting blood flow to these areas in response to changes in temperature. Increased blood flow to the tongue helps to dissipate heat during periods of physical exertion or exposure to warm environments. Conversely, reduced blood flow conserves heat when necessary. This thermoregulatory function is important in maintaining the overall temperature balance of the oral cavity, especially during periods of intense muscular activity, such as speaking or chewing.

Facilitation of Healing and Tissue Repair

The lingual artery plays a vital role in supporting the healing and repair of tissues in the mouth and tongue. In the event of injury, such as cuts or abrasions to the tongue or oral mucosa, the artery supplies the necessary blood flow to promote healing. Adequate oxygen and nutrient delivery are essential for tissue regeneration and wound healing. The robust blood supply provided by the lingual artery ensures that injured tissues can recover efficiently and helps prevent complications such as infections or delayed healing.

Contribution to Collateral Circulation

The lingual artery contributes to the collateral circulation in the head and neck by forming anastomoses with nearby arteries, such as the facial artery. This collateral circulation ensures that blood can continue to flow to critical areas in the mouth and tongue, even if one artery becomes blocked or damaged. By maintaining a rich vascular network, the lingual artery helps safeguard the oral cavity against ischemic events, ensuring that key structures remain well-nourished and functional.

Clinical Significance

The lingual artery is of critical importance in both surgical and medical contexts due to its role in supplying blood to the tongue, floor of the mouth, and sublingual glands.

Oral and Tongue Surgeries

During oral and tongue surgeries, such as glossectomies (partial or total removal of the tongue) or sublingual gland excisions, the lingual artery must be carefully managed to prevent significant bleeding. Its deep location beneath the tongue’s muscles and proximity to the hypoglossal nerve also requires careful dissection to avoid nerve damage.

Trauma and Injury

In cases of trauma or lacerations involving the tongue or oral cavity, injury to the lingual artery can result in substantial hemorrhage due to its robust blood flow. Quick identification and management of the artery are crucial in controlling bleeding and ensuring the proper healing of oral tissues.

Vascular Conditions

The lingual artery may be involved in vascular anomalies, such as aneurysms or arteriovenous malformations, affecting the oral cavity. Embolization or surgical ligation of the lingual artery may be required to control abnormal blood flow in such conditions.

Dental and Orthognathic Procedures

In certain dental surgeries and orthognathic (jaw) procedures, the lingual artery must be considered to avoid accidental damage during incisions or manipulation of oral structures.