MYOLOGY 89 



Origin. — The anterior branch of >the bifurcated tracheo-lateralis. 

 Insertion. — To the anterior extremity of the third half ring of the 

 bronchus of the same side. 

 . Shape. — ^A small fasciculus. 



Relations. — ^Internally with the trachea, and externally. with the 

 skin and other integument. 



Action. — ^A tensor of the inferior larynx. 



Broncho-trachealis Brevis (Fig. 20, No. 3). Location. —Posterior 

 part of the inferior extremity of the trachea. 



Origin. — From just beneath the broncho-trachealis anticus muscle. 



Insertion. — ^Extends obUquely across the inferior larynx and is 

 inserted to the posterior end of the second bronchial ring. 



Shape. — Rather short, strong, straight, subcyUndrical. 



Relations. — Internally with the trachea, and laterally with the 

 broncho-tracheaUs posticus. 



Action. — ^A tensor of the inferior lar3rnx. 



Bronchialis Posticus (Fig. 21, No. 2). Location. — Supero-lateral 

 side of the anterior end of the bronchi. 



Origin. — From the lateral inferior margin of the last tracheal ring. 



Insertion. — Passing obUquely across the larynx it inserts to the 

 posterior extremity of the second hah ring of the bronchus. 



Shape. — Small, thick, spindle-shaped. 



Relations. — Internally with the trachea, inferiorly with the bron- 

 chiaUs anticus, and superiorly with the broncho-tracheaUs brevis. 



Action. — ^A tensor of the larynx. 



Bronchialis Anticus (Fig. 21, No. i). Location. — Inferior to the 

 former muscle. 



Origin^ — From the last ring of the trachea. 



Insertion. — The fibers pass obliquely forward and become in- 

 serted to the rim of the arytenoid cartilage of the inferior larynx, 

 and the anterior extremities of the first and second half rings of 

 the bronchus. 



Shape. — Thick, spindle-shaped; about twice the size of the bron- 

 chialis posticus. 



Relations. — It is crossed at its origin by the broncho-tracheaUs 

 anticus and is related internally with the bronchus and end of the 

 trachea. 



Action. — A tensor of the larynx. 



Stemo-trachealis (Fig. 20, No. i). Location. — The inferior re- 

 gion of the trachea above the above-named muscles 



