THE HEAD AND NECK 1287 



lar5mgeal surface of the epiglottis, the inner surfaces of the arytenoid 

 cartilages and of the aryteno-epiglottidean folds, and over the 

 margins of the false vocal cords. 



The mucous membrane contains a large number of acinous 

 mucous glands, the ducts of which open freely on the surface, 

 except over the true vocal cords, where there are no glands. They 

 are arranged in groups, as follows : (i) epiglottidean, which are 

 very numerous, and occupy the pits on the laryngeal surface of 

 the epiglottis ; (2) arytenoidean, in front of the ar^-tenoid cartilages, 

 and in the adjacent portions of the aryteno-epiglottidean folds ; 

 (3) along the false vocal cords ; and (4) in the wall of the larj-ngeal 

 saccule, where they are very numerous. 



Intrinsic Muscles. — ^These are the muscles by which the cartilages 

 are moved upon each other so as to affect the condition of the 



L 



Epiglottis— 



Superior Comu of Thyroid- 

 Cartilage 



Cuneiform Cartilage _ ' 

 (Wrisberg) / 



CorniCTilum Laryngisw — 

 (Santorini) bi 



\ 



Ary tieno-«piglottideas _* . 

 (Arytinoideus Obliquus) \ 

 Arytsenoideus Transversus 



Crico-arytienoideus Posticus_ 



Crico-thyroid Joint 



Cricoid Cartilage " 



Trachea 



b' 'd 



^^G. 535. — The iNTkiNsic Muscles of the Larynx (Posterior View). 



vocal cords. They are as follows : the crico-th5n-oid, posterior 

 crico-arytenoid, lateral crico-arytenoid, arytenoid, and arytaeno- 

 epiglottideus. The arytenoid is a single muscle, but all the others 

 are arranged in pairs. 



Crico-thyroid— Origtw. — ^The front of the anterior part of the 

 cricoid cartilage, extending as far as the median line. 



Insertion. — (i) The lower margin of the ala of the thyroid cartilage, 

 and (2) the front of the inferior comu 



