316 HEALTH AND DISEASE 



CricO-PharyngeilS. Placed behind the thyro-pharyngeus. 



Origin. From the outer surface of the cricoicl cartilage. 



Insertion. Into the roof of the pharynx, where its fibres interlace with 

 those of its fellow. 



Action. The three muscles last described constrict the pharynx. 



Stylo-PharyngeilS. A triangular muscle situated above the pharynx. 



Origin. From the inner surface of the long cornu of the hyoid bone. 



Insertion. Below it spreads out its fibres and becomes inserted into 

 the outer edge of the pharynx. 



Action. To dilate the pharynx. 



MUSCLES OF THE SOFT PALATE 



PalatO-PharyngeilS. This muscle lies in the posterior part of the 

 soft palate. It is attached to its fellow on the opposite side, to the outer 

 wall of the pharynx, and to the superior border of the thyroid cartilage. 



Action. To tighten the soft palate, and raise it during swallowing. 



Tensor Palati. A small, flat, thin muscle placed above the pharynx. 



Origin. From the styloid process of the petrous temporal bone. 



Insertion. The tendon of this muscle plays over a pulley-like arrange- 

 ment on the free process of the pterygoid bone, and, after spreading out, 

 becomes inserted into the posterior wall of the pharynx. 



Action. To render the front portion of the palate tense. 



LevatOP Palati. A thin band of muscle situated above the pharynx. 



Origin. AVith the muscle last described from the styloid process of the 

 temporal bone. 



Insertion. Into the soft palate. 



Action. To raise the velum palati. 



MUSCLES OF THE LARYNX 



Thyro-Hyoid Muscle. A flat triangular muscle spread over the side 

 of the thyroid cartilage. 



Origin. From the entire length of the heel process of the hyoid or 

 tongue bone. 



Insertion. Into an oblique ridge on the outer side of the thyroid 

 cartilage. 



Action. To raise the larynx and draw it forward. 



Hyo-Epiglottideus. A short, small bundle of fibres situated at the 

 root of the tongue in a mass of fatty tissue. 



Origin. From the upper surface of the body of the hyoid bone. 



