DISSECTING MANUAL. 



each side is a mucous fold (aryteno-epiglottidean) stretching 

 from the epiglottis to the arytenoid and presenting posteriorly 

 two elevations, the cuneiform tubercle and tubercle of San- 

 torini, caused by those cartilages. The upper subdivision 

 (vestibule) extends from the superior aperture to the false 

 cords, narrowing rapidly. The thyro-epiglottidean ligament 

 bulges (cushion, or tubercle of the epiglottis) into its anterior 

 wall, low down. At each side, posteriorly, the cuneiform car- 

 tilage makes a vertical ridge which ends in the false cord; and 

 behind this the anterior margin of the arytenoid and the car- 

 tilage of Santorini make another ridge which ends in the true 

 cord. [964] 



The middle subdivision extends from the false to the true 

 cords. The false vocal cords are two soft mucous folds which 

 enclose the superior thyro-arytenoid ligaments and contain 

 some muscle fibres ; they run from the angle between the thy- 

 roid alsc to the back of each lateral wall; the aperture between 

 them is the false glottis. The true vocal cords are two prominent 

 and whitish mucous folds enclosing the inferior thyro-aryte- 

 noid ligaments ; they run from the angle between the thyroid 

 alae to the arytenoid vocal processes. The true glottis (rima 

 glottidis) consists of the aperture between the true cords 

 (glottis vocalis) together with that between the bases and 

 vocal processes of the arytenoids (glottis respiratoria) . Each 

 side wall, between the true and false cord, is a recess (laryngeal 

 sinus) which somewhat undermines the false cord; at its fore- 

 part a narrow aperture leads into a diverticulum (laryngeal 

 saccule) which ascends under the false cord and onto the thy- 

 roid cartilage, usually to the upper border. The lower subdivis- 

 ion lies below the true cords ; it widens out, becomes circular, 

 and opens into the trachea. [965] 



Intrinsic Laryngeal Muscles. 



Crico-thyroid. Origin; lower border and outer surface of 

 anterior arch of cricoid. Insertion ; (anterior, or oblique part) 



[92] 



