Tongue Muscles: The Power Of Relaxation

The tongue is a muscular organ situated in the oral cavity, and an accessory digestive organ. It is made up of eight muscles, which are divided into two groups: intrinsic and extrinsic. The intrinsic muscles are four paired muscles that originate and attach to other structures within the tongue. These muscles affect the tongue's shape and size, and play a role in guiding speech, eating, and swallowing. The extrinsic muscles, on the other hand, originate from structures outside the tongue and insert into it. These muscles produce movements that the intrinsic muscles cannot, such as protrusion, retraction, depression, and elevation of the tongue. So, which muscles are responsible for lowering the tongue?

The genioglossus muscle is involved in depressing the tongue

The genioglossus muscle is a large, thick muscle that contributes significantly to the shape of the tongue. It is one of the paired extrinsic muscles of the tongue. The genioglossus muscle arises from the mandibular symphysis and inserts onto the body of the hyoid bone and the entire length of the tongue. It is innervated by the hypoglossal nerve, or cranial nerve XII, which is one of 12 paired cranial nerves. The hypoglossal nerve controls muscles in the back of the throat, and damage to it can cause sleep apnea.

The genioglossus muscle also acts with the hyoglossus muscle to depress and retract the tongue. The hyoglossus muscle is located in the floor of the oral cavity, immediately lateral to the geniohyoid, and it arises from the hyoid bone and inserts onto the lateral aspect of the tongue. The hyoglossus and genioglossus muscles are synchronous with respiration, and their activity correlates with increases in pharyngeal airway size during breathing.

The genioglossus muscle is often used as a proxy to test the function of the hypoglossal nerve, by asking a patient to stick out their tongue. Peripheral damage to the hypoglossal nerve can result in deviation of the tongue to the damaged side. Lesions of the cerebral hemisphere may cause weakness of the contralateral genioglossus, so that the tongue deviates toward the side of the weak arm and leg.

The hyoglossus muscle is involved in depressing and retracting the tongue

The tongue is a muscular hydrostat, a structure similar to an octopus's tentacles or an elephant's trunk. It is made up of eight separate muscles that intertwine to create a flexible matrix. These muscles give the tongue its agility and huge range of motion, allowing it to contort into various shapes and postures.

The hyoglossus muscle is one of the muscles that make up the tongue. It is a flat, wide, thin, and quadrilateral extrinsic muscle. It originates from the hyoid bone and inserts onto the lateral aspect of the tongue. The hyoglossus muscle is located in the floor of the oral cavity, immediately lateral to the geniohyoid.

The hyoglossus muscle receives its innervation from the hypoglossal nerve (cranial nerve XII), specifically the lateral branch of this nerve. The lingual artery, a branch of the external carotid artery, passes deep to the hyoglossus muscle, while the lingual vein passes medial to it. The dorsal lingual artery arises beneath the hyoglossus muscle and supplies the mucous membrane of the posterior part of the dorsum of the tongue.

The styloglossus muscle is involved in retracting and elevating the tongue

The tongue is a soft, flexible matrix of eight separate muscles. These muscles intertwine to form a muscular hydrostat, which is a structure similar to an elephant's trunk or an octopus's tentacles. The tongue's muscles are highly agile and supple, with an impressive range of motion and shape-preserving abilities.

The styloglossus muscle is a thin, paired muscle located on either side of the oropharynx. It originates from the styloid process of the temporal bone and inserts onto the lateral aspect of the tongue. The styloglossus muscle is the shortest and smallest of the three styloid muscles. By contracting, the styloglossus muscle retracts the tongue and elevates its lateral aspects. This action draws up the sides of the tongue to create a trough for swallowing.

The styloglossus is innervated by the hypoglossal nerve (CN XII), which provides motor innervation to all of the intrinsic and extrinsic muscles of the tongue, except for the palatoglossus muscle. The hypoglossal nerve carries motor fibres to the intrinsic tongue muscles and to other muscles such as the thyrohyoid, hyoglossus, genioglossus, and geniohyoid. The styloglossus muscle is one of four extrinsic muscles, along with the genioglossus, hyoglossus, and palatoglossus. These extrinsic muscles produce movements that the intrinsic muscles cannot, such as protrusion, retraction, depression, and elevation of the tongue.

The intrinsic muscles of the tongue, on the other hand, are primarily responsible for changing the shape of the tongue, which is essential for speaking. There are four paired intrinsic muscles: the superior longitudinal, inferior longitudinal, transverse, and vertical muscles. These muscles affect the tongue's shape and size, enabling actions such as tongue rolling and facilitating speech, eating, and swallowing.

The palatoglossus muscle is involved in elevating the posterior portion of the tongue

The tongue is a muscular hydrostat, a flexible matrix of eight separate muscles that intertwine. The tongue's muscles are categorised as intrinsic or extrinsic. The intrinsic muscles are involved in changing the shape of the tongue, which is essential for speaking, eating, and swallowing. The extrinsic muscles, on the other hand, originate from structures outside the tongue and insert onto it, anchoring it to the rest of the head and neck.

The palatoglossus muscle is one of the four extrinsic muscles of the tongue. It is innervated by the vagus nerve (CN X) via branches of the pharyngeal plexus, unlike the other tongue muscles, which are innervated by the hypoglossal nerve (CN XII). The palatoglossus muscle is also associated with the soft palate, arising from the palatine aponeurosis and inserting along the tongue.

The function of the palatoglossus muscle is to elevate the posterior portion of the tongue. This action plays a significant role during swallowing by propelling the food bolus toward the oesophagus and preventing retrograde flow. It also closes the oropharyngeal isthmus and maintains the palatoglossal arch, preventing the spill of saliva from the vestibule into the oropharynx.

The palatoglossus muscle's ability to elevate the tongue depends on its region of attachment in the soft palate. When the attachment area is near the uvula, the muscle's mechanical ability to elevate the tongue may be limited due to the lack of a rigid anchoring point. However, this attachment is favourable for lowering the soft palate. In contrast, when the attachment area is relatively large into the anterior portion of the velum, there is a considerable increase in the muscle's ability to elevate the tongue, but this attachment is not conducive to lowering the soft palate.

The superior longitudinal muscle is involved in altering the shape of the tongue

The tongue is a muscular organ formed by a complex arrangement of intrinsic and extrinsic muscles. The intrinsic muscles are responsible for adjusting the shape and orientation of the organ. They originate and attach to other structures within the tongue. The extrinsic muscles, on the other hand, extend outside of the organ to anchor it to surrounding bony structures.

The superior longitudinal muscle is one of four paired intrinsic muscles of the tongue. These muscles are named by the direction in which they travel. The superior longitudinal muscles are made up of a thin layer of muscle fibres travelling in a mixture of oblique and longitudinal axes just deep to the superior mucosal surface of the organ. Contraction of the superior longitudinal muscle results in the shortening and thickening of the tongue.

The other intrinsic muscles are the inferior longitudinal, transverse, and vertical muscles. Contraction of the transverse muscles lengthens and thins the tongue. The vertical muscle, meanwhile, flattens the tongue by simultaneously widening and elongating it.

The intrinsic muscles of the tongue are involved primarily in changing the tongue's shape, which is essential for speaking, eating, and swallowing. The tongue moves food around the mouth with the help of the buccinator muscle, mixes it with saliva, and helps to separate undesired particles. It also enables the formation of the food bolus in the oral preparatory phase of swallowing.

The extrinsic muscles of the tongue, meanwhile, are in charge of moving the tongue in different directions. One example of an extrinsic muscle is the genioglossus muscle, which contributes significantly to the shape of the tongue. It allows for the protrusion and depression of the tongue.

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