DISSECTION OF THE 11KAI) AND NK( K 213 



Some Enclosed Spaces of the Neck. 



(a) Subcutaneous space between fascia superliruilis ;m<l superficial 



layer of fascia colli. 



(b) Superficial subaponeurotic space between superficial and deep 



layers of fascia colli. 



(c) Suprasternal space. 



(d) Previsceral space between the deep layer of the fascia colli in 



front and the visceral and vascular sheaths behind. It contains 

 fat and deep lymphatic glands. 



(e) Retrovisceral or prevertebral space bounded in front by visceral 



sheath, behind by spine, and laterally by attachments of visceral 

 sheath to spine. 



Surgical Anatomical Points. 



(a) Abscesses within the visceral sheath either are secondary to infections 



involving the organs contained within it or are due to primary pyo- 

 genie infection of the areolar tissue inside it. 



(b) Abscesses secondary to disease of the retropharyngeal lymph-glands 



lie in front of the fascia praevertebralis in the space between it 

 and the visceral sheath. 



(c) Abscesses secondary to disease of the cervical vertebrae lie behind 



the fascia praevertebralis and spread lateralward behind the vas- 

 cular sheath; they usually point behind the M. sternocleidomns- 

 toideus, and may be opened by an incision at the posterior border 

 of this muscle. 



(d) The carotid chain of lymph-glands (lymphoglandulae cervicales pro- 



fundae) lies inside the common part of the vascular sheath. Ab- 

 scess resulting from disease of these glands usually points upon 

 the surface, owing to the formation of adhesions: first between the 

 gland and the vascular sheath, then between the latter and the 

 superficial layer of the fascia colli, and finally between the latter 

 and the skin. 



Sternocleidomastoid Muscle (M. sternocleidomastoideus). (Vide 



Fig. 91, p. 219.) 



Note that it divides the neck into an anterior and a posterior 

 triangle. Remove from its surface the covering derived from 

 the superficial layer of the fascia colli. Ascertain exactly its 

 origin, insertion, innervation, and action. Why does Krausr 

 designate it " the quadrigeminal muscle of the head" Which 

 of the four parts (sternomastoid, sterno-occipital, cleidomastdid, 

 and cleido-occipital) are present in your cadaver? 



Posterior Triangle of the Neck. (Vide Fig. 91, p. 219.) 



Remove, over the posterior triangle, the superficial and deep 

 layers of the fascia colli; note that the former covers the whol< 

 triangle, the latter only its inferior part as far as the upper 



