

REGION OF THE CAROTID ARTERIES. 81 



Cricotomy consists in dividing the cricoid cartilage ; 

 but it is an operation rarely resorted to. 



Foreign bodies in the trachea are naturally directed 

 towards the right bronchus, because it is wider than the 

 left. The septum at the bottom of the trachea, which 

 separates the bronchi, occupies the left of the median 

 line. 



The right bronchus is shorter and more horizontal 

 than the left, being about one inch long. The left is 

 about two inches in length, and is directed more obliquely 

 than the right. 



SUKGICAL ANATOMY OF THE STERNO-MASTOID RE- 

 GION, OK REGION OF THE CAROTID ARTERIES 

 ABOVE THE STERNO-CLAVICULAR ARTICULA- 

 TION. 



The boundaries of this region may be sufficiently 

 stated as being those occupied by the sterno-cleido-mas- 

 toid muscle itself. This muscle forms an oblique rec- 

 tangular eminence, and is attached above to the mastoid 

 process and the superior curved line of the occipital bone, 

 its broad tendinous insertion being blended with the 

 fibres of origin of the trapezius ; passing downwards and 

 forwards, its muscular fibres become divided, the anterior 

 set collecting themselves into a round fusiform bundle, 

 to be attached to the manubrium sterni, and a posterior 

 bundle, a flattened riband-like band, separated from the 

 former by a cellular interval, and attached for a variable 

 distance along the inner and upper aspect of the clavicle. 

 (Occasionally these clavicular fibres pass along the whole 

 inner two-thirds of the clavicle, forming a muscular 

 layer, almost covering in the posterior triangular space.) 

 This interval in the disposition of the muscular fibres is 



