MUSCLES OF THE NECK. 73 



Mylo-hyoid, 5 from the mylo-hyoid ridge of the lower jaw, into the body of 

 the hyoid bone and a fibrous raphe in the median line running from the hyoid 

 bone to the chin. Action, elevates the hyoid bone and draws it forwards, 

 also forms the floor of the mouth. Nerve, mylo-hyoid branch of inferior 

 dental. 



Genio-hyoid, 6 from the inferior genial tubercle of the inferior maxillary, 

 into the body of the hyoid bone. Action, same as the mylo-hyoid. Nerve, 

 hypoglossal. 



Genio-hyo-glossus,/hwz the superior genial tubercle of the inferior maxillary, 

 into the body of the hyoid bone, the side of the pharynx, and the whole 

 length of the under surface of the tongue, forming a fan-like muscle. Action, 

 to retract and protrude the tongue. Nerve, hypoglossal. 



Hyo-glossus 8 (the basio-kerato-chondro-glossus), from the body of the hyoid 

 bone, its lesser cornu, and the whole length of its greater cornu, into the 

 side of the tongue. Action, to draw down the side of the tongue. Nerve, 

 hypoglossal. 



Stylo-glossus, 9 from the styloid process and the stylo-maxillary ligament, 

 into the side of the tongue and the hyo-glossus muscle. Action, to elevate 

 and retract the tongue. Nerve, hypoglossal. 



Lingualis, lies between the hyo-glossus and the genio-hyo-glossus, from the 

 base to the tip of the tongue, along its under surface ; some of its fibres being 

 attached to the hyoid bone. Action, to elevate the centre of the tongue. 

 Nerve, chorda tympani. 



Inferior Constrictor, from the sides of the cricoid and thyroid cartilages, 

 into the fibrous raph6 of the pharynx. Action, to contract the pharyngeal 

 calibre. Nerves, glosso-pharyngeal, pharyngeal plexus, and external laryn- 

 geal. 



Middle Constrictor, from the cornua of the hyoid bone and the stylo-hyoid 

 ligament, into the pharyngeal raph6. Action, to constrict the pharynx. 

 Nerves, glosso-pharyngeal, pharyngeal plexus. 



Superior Constrictor, from the lower third of the margin of the internal 

 pterygoid plate and its hamular process, the contiguous part of the palate 

 bone, the tendon of the tensor palati, the pterygo-maxillary ligament, part 

 of the alveolar process of the lower jaw and the side of the tongue, into 

 the pharyngeal raph6 and the pharyngeal spine of the occipital bone. 

 Action, to constrict the pharynx. Nerves, glosso-pharyngeal, pharyngeal 

 plexus. 



Stylo -pharyngeus, 10 from the inner side of the base of the styloid process, 

 into the constrictor and palato-pharyngeus muscles, and the thyroid car- 

 7 



