138 SURGICAL APPLIED ANATOMY. [Chap. ix. 



deep pressure be made over the line of the carotid 

 vessels at the level of the cricoid cartilage, the promi- 

 nent anterior tubercle of the transverse process of the 

 sixth cervical vertebra can be felt. This is known as 

 the " carotid tubercle." The carotid artery lies directly 

 over it, and in ligaturing that vessel some surgeons 

 make important use of this tubercle as a landmark. If 

 a horizontal section of the neck, in a muscular subject, 

 taken about the level of the sixth cervical vertebra, 

 be viewed, it will be observed that the whole of the 

 body of the vertebra divided will lie within the an- 

 terior half of the section. 



The middle line. In the receding angle below 

 the chin the hyoid bone can be felt, and its body and 

 greater cornua well made out. About a finger's 

 breadth below it is the thyroid cartilage. The details 

 of this latter are readily distinguished, and below it 

 the cricoid cartilage, crico-thyroid space, and trachea 

 can be easily recognised. The separate rings of the 

 trachea cannot be felt. The trachea is less easily made 

 out, as it passes down the neck. As it descends it 

 takes a deeper position, and at the upper border of 

 the sternum lies nearly one and a half inches from the 

 surfaca 



The rima glottidis corresponds to the middle of the 

 anterior margin of the thyroid cartilage. 



Unless enlarged, the thyroid gland cannot be made 

 out with certainty. According to Mr. Hold en, the 

 pulse of the superior thyroid artery can be felt at its 

 upper and anterior part. 



The anterior jugular veins descend on either side 

 of the middle line upon the sterno-hyoid muscles. 

 They commence in the submaxillary region, pierce the 

 fascia just above the inner end of the clavicle, and, 

 passing behind the origin of the sterno-mastoid 

 muscle, are lost to view. The inferior thyroid veins 

 lie in front of the trachea, below the isthmus. 



