310 LABORATORY MANUAL OF HUMAN ANATOMY 



Glottis. 



The two plicae vocales together form the glottis (O. T. glottis 

 vera), the slit between them being known as the rima glottidis. 

 The rima glottidis is divisible into 



(a) Intermembranous part (pars intermembranacea) (0. T. glottis vo- 



calis), the anterior longer part, between the plicae vocales. 



(b) Intercartilaginous part (pars intercartilaginea) (0. T. glottis respira- 



toria), the posterior shorter part, between the medial surfaces of 

 the arytaenoid cartilages. 



The cavity below the rima glottidis i.e., the inferior cavity 

 of the larynx is called the aditus glottidis inferior. It leads 

 below into the trachea. 



Mucous Membrane of the Larynx (Tunica mucosa laryngis). 

 Observe 



(a) Mucous laryngeal glands (Gl. laryngeae). 



(aa) Anterior (GL laryngeae anteriores), in front of and behind 



the epiglottis. 



(ab) Middle (GL laryngeae mediae), on the plicae ventriculares, 



in the ventricles, and around the cuneiform cartilages. 



(ac) Posterior (GL laryngeae posteriores) , in front of, in, and 



behind the M. arytaenoideus transversus. 



(b) Lymph-nodules of larynx (noduli lymphatici solitarii), especially 

 on the posterior surface of the epiglottis and in the ventricles. 



Hyothyreoid Membrane and Laryngeal Muscles. 



With a probe stuff the ventricle of the larynx and its appen- 

 dix full of moist cotton. Fasten the larynx with pins on a 

 wooden block, the anterior surface upward. 



Find the ramus externus and ramus internus of the N. laryn- 

 geus superior, the N. recurrens, the superior and inferior laryn- 

 geal vessels, and avoid injury to them in the subsequent dissec- 

 tion. Eemove the Gl. thyreoidea and the Mm. omohyoideus, 

 sternohyoideus, sternothyreoideus, thyreohyoideus, and con- 

 strictor pharyngis inferior. Clean and study the following 

 structures : 



(a) Hyothyreoid membrane (membrana Jiyothyreoidea) (0. T. thyro- 

 hyoid membrane). Observe how it is perforated by the A. 

 and V. laryngea superior and by the ramus internus N. 

 laryngei superioris. 



(aa) Middle hyothyreoid ligament (ligamentum Jiyofhyreoideum 



medium). 



(ab) Lateral hyothyreoid ligament (ligamentum hyothyreoideum 



laterale). 



