The |tongue| is predominantly a muscular organ, which has a great capacity for both slow and rapid shape changes. The muscular |fibers| of the |tongue| run in various directions. These |fibers| are divided into two sets, the extrinsic muscles and the intrinsic muscles. The extrinsic glossal (tongue) muscles connect the |tongue| to the bones around it (the lower jaw in front, the |hyoid bone| below, the base of the |skull| behind, and the palate above). They take up a large space within the arc of the lower jaw. There are four sets of extrinsic muscles on each side of the head. They are the hypoglossus, styloglossus, platoglossus, and genioglossus muscle. These muscles work together in a coordinated way to bring about bulk movements of the |tongue|. Within the |tongue| are the intrinsic glossal muscles, which control the detailed shape changes of the organ. The |fibers| of the intrinsic muscles are grouped into four assemblages: two running from the front to the back of the |tongue|, one transversely and the last vertically.
