54 ANATOMY OF THE HEAD AND NECK. 



and terminates in the cardiac plexus. The middle gan- 

 glion is sometimes wanting. 



The inferior cervical ganglion occupies the interval 

 between the first rib and the transverse process of the 

 seventh cervical vertebra, and will be seen in a later stage 

 of the dissection, (p. 59.) 



DISSECTION VIII. 



The upper portion of the sternum should now be removed, with the 

 sternal half of the clavicle attached, and the ribs cut away on each 

 side as far as the insertions of the scaleni muscles ; this will expose 

 the deep vessels of the neck in their relation to the heart ; the cellu- 

 lar tissue which covers them is to be carefully removed by following 

 the vessels downward from the point at which they are already dis- 

 sected in the neck. The sterno-clavicular articulation should, how- 

 ever, be first examined, and this may be done before it is detached 

 from the thorax. 



STERNO-CLAVICULAR ARTICULATION. 



The internal extremity of the clavicle is strongly con- 

 nected with the upper bone of the sternum by several 

 ligaments. 



The anterior sterno-clavicular ligament is a stout band 

 of fibres, passing from the anterior surface of the sternal 

 end of the clavicle, downward and inward, to the upper 

 and anterior part of the first bone of the sternum. 



The posterior sterno-clavicular ligament, less developed 

 than the preceding, occupies a situation, and has a similar 

 origin and insertion on the inner aspect of the articulation. 



The inter-clavicular ligament is a strong rounded cord, 

 intervening between the superior surfaces of the clavi- 

 cles, and is closely attached to the incisura semilunaris of 

 the sternum. 



The costo-clavicular ligament is a band passing obliquely 

 forward from the under surface of the clavicle at its sternal 

 end, to the cartilage of the first rib ; sometimes the clavicle 

 touches the rib, and has an articular surface at this point ; 

 the subclavius muscle lies in front of this ligament. 



An inter-articular fibro-cartilage will be found on divid- 

 ing these ligaments and detaching the clavicle; it is nearly 

 circular in form, and thicker in the centre than at its cir- 

 cumference ; it is adherent by its edges to the ligaments 

 which surround the articulation. Its sternal surface is 



