Tongue (Taste Areas)

Extrinsic Muscles

Although the tongue may seen to be floating freely in the floor of the mouth, it is actually anchored in all directions by the four extrinsic muscle sets, which work together to move the tongue in virtually any direction. The movements they produce, however, are pretty coarse, and fine shape changes are the province of the intrinsic tongue muscles. The extrinsic muscles are arranged in four groups. (1) The "genio-glossus" runs from the front of the lower jaw into the tongue from tip to base. Contraction of these muscles (on either side) makes the tongue stick out as its whole foundation is pulled forward. (2) The "hyo-glossus" (sometimes called the "geniohyoid") is a flat, straplike muscle, which passes from the side of the tongue down to one arm of the wishbone-shaped hyoid bone in the throat. Movement of these muscles pulls the sides of the tongue downward. (3) Linking the sides of the tongue to the base of the skull through the bony styloid process (cell network) are the "styo-glossals." They act to pull the tongue backward and upward. (4) The "palato-glossals" are connected to the sides and back of the tongue and run to the rear of the palate to lift the sides of the tongue when they are contracted.