The muscles of tongue can be divided into intrinsic and extrinsic groups.

The intrinsic muscles lie entirely within the tongue

Tongue

The tongue is a muscular hydrostat on the floors of the mouths of most vertebrates which manipulates food for mastication. It is the primary organ of taste , as much of the upper surface of the tongue is covered in papillae and taste buds. It is sensitive and kept moist by saliva, and is richly...

, while the extrinsic muscles attach the tongue to other structures.

The extrinsic muscles reposition the tongue, while the intrinsic muscles alter the shape of the tongue for talking and swallowing.

Extrinsic muscles

Extrinsic tongue muscles, by definition, originate from structures outside the tongue and insert into the tongue. The four paired extrinsic muscles protrude, retract, depress, and elevate the tongue:

Muscle

From

Nerve

Function >- | Genioglossus muscle

mandible

hypoglossal nerve Hypoglossal nerve The hypoglossal nerve is the twelfth cranial nerve , leading to the tongue. The nerve arises from the hypoglossal nucleus and emerges from the medulla oblongata in the preolivary sulcus separating the olive and the pyramid. It then passes through the hypoglossal canal...

>- | Hyoglossus muscle

hyoid bone Hyoid bone The hyoid bone is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. At rest, it lies at the level of the base of the mandible in the front and the third cervical vertebra behind.Unlike other bones, the hyoid is only distantly...

hypoglossal nerve Hypoglossal nerve The hypoglossal nerve is the twelfth cranial nerve , leading to the tongue. The nerve arises from the hypoglossal nucleus and emerges from the medulla oblongata in the preolivary sulcus separating the olive and the pyramid. It then passes through the hypoglossal canal...

>- | Styloglossus muscle

styloid process

hypoglossal nerve Hypoglossal nerve The hypoglossal nerve is the twelfth cranial nerve , leading to the tongue. The nerve arises from the hypoglossal nucleus and emerges from the medulla oblongata in the preolivary sulcus separating the olive and the pyramid. It then passes through the hypoglossal canal...

>- | Palatoglossus muscle Palatoglossus muscle The palatoglossus, glossopalatinus, or palatoglossal muscle is a small fleshy fasciculus, narrower in the middle than at either end, forming, with the mucous membrane covering its surface, the glossopalatine arch....

palatine aponeurosis Palatine aponeurosis Attached to the posterior border of the hard palate is a thin, firm fibrous lamella called the palatine aponeurosis, which supports the muscles and gives strength to the soft palate....

pharyngeal branch of vagus nerve Pharyngeal branch of vagus nerve The pharyngeal branch of the vagus nerve, the principal motor nerve of the pharynx, arises from the upper part of the ganglion nodosum, and consists principally of filaments from the cranial portion of the accessory nerve....

depresses the soft palate Soft palate The soft palate is the soft tissue constituting the back of the roof of the mouth. The soft palate is distinguished from the hard palate at the front of the mouth in that it does not contain bone.... , moves the palatoglossal fold towards the midline, and elevates the back of the tongue.

Intrinsic muscles

Four paired intrinsic muscles of the tongue originate and insert within the tongue, running along its length. These muscles alter the shape of the tongue by: lengthening and shortening it, curling and uncurling its apex and edges, and flattening and rounding its surface.

• The superior longitudinal muscle
  Superior longitudinal muscle
  The Longitudinalis linguæ superior is a thin stratum of oblique and longitudinal fibers immediately underlying the mucous membrane on the dorsum of the tongue.-Course:...
  
  runs along the superior surface of the tongue under the mucous membrane, and elevates, assists in retraction of, or deviates the tip of the tongue. It originates near the epiglottis
  Epiglottis
  The epiglottis is a flap that is made of elastic cartilage tissue covered with a mucous membrane, attached to the entrance of the larynx. It projects obliquely upwards behind the tongue and the hyoid bone, pointing dorsally. The term, like tonsils, is often incorrectly used to refer to the uvula...
  
  , the hyoid bone
  Hyoid bone
  The hyoid bone is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. At rest, it lies at the level of the base of the mandible in the front and the third cervical vertebra behind.Unlike other bones, the hyoid is only distantly...
  
  , from the median fibrous septum.
• The inferior longitudinal muscle
  Inferior longitudinal muscle
  The Longitudinalis linguæ inferior is a narrow band situated on the under surface of the tongue between the Genioglossus and Hyoglossus.-Course:...
  
  lines the sides of the tongue, and is joined to the styloglossus muscle.
• The verticalis muscle
  Verticalis muscle
  The Verticalis linguæ is found only at the borders of the forepart of the tongue.Its fibers extend from the upper to the under surface of the organ....
  
  is located in the middle of the tongue, and joins the superior and inferior longitudinal muscles.
• The transversus muscle
  Transversus muscle
  The Transversus linguæ is a muscle of the tongue. It consists of fibers which arise from the median fibrous septum and pass lateralward to be inserted into the submucous fibrous tissue at the sides of the tongue....
  
  divides the tongue at the middle, and is attached to the mucous membrane
  Mucous membrane
  The mucous membranes are linings of mostly endodermal origin, covered in epithelium, which are involved in absorption and secretion. They line cavities that are exposed to the external environment and internal organs...
  
  s that run along the sides.