THE HEAD AND NECK. 



5 1 



NERVE-SUPPLY OF THE STERNO-MASTOID. This muscle, as you may now see, 

 receives numerous twigs from the spinal accessory nerve as this nerve is passing 

 through the muscle. It also receives nerves from the cervical plexus. Lift the 

 muscle very carefully, and demonstrate these nerves on your own work. 



The Upper Attachments and Special Structures Formed by the First 

 Layer of Deep Cervical Fascia (Fig. 26). The same fascia that covers the 

 sterno-mastoid muscle is continued upward and forms special structures. You 

 will now dissect and study these. Cut along the lower margin of the jaw to the 

 symphysis rnenti. Avoid the facial artery and vein in front of the masseter 

 muscle. 



Distribution of the Deep Cervical Fascia Above (Fig. 26). You now 

 see this fascia extending from the sterno-mastoid muscle to the masseter muscle 



Capsule for 

 submaxil- 

 lary gland 



Sheath for di- 

 gastric muscle 





Sheath for the de- 

 pressors of the 

 hyoid bone 



Mandibular attachment 



Masseteric fascia 



Parotid fascia 



Stylo-mandibular 

 ligament 



Sheath for the 

 sterno-mastoid 



The carotid 

 sheath 



Sterno-mastoid, 

 cut 



Trapezius 



Scalenus posticus 



Scalenus medius 



Scalenus anticus 



Fi<;. 26. SCHEME OF UPPKR ATTACHMENTS OF AND SPECIAL NAMKS FOR DEEP CERVICAL FASCIA. 



and parotid gland, forming their specific fasciae. You see it extending from the 

 styloid process to the jaw as the stylo-maxillary ligament ; you see it forming a 

 capsule for the submaxillary gland, and continuing forward to invest the anterior 

 belly of the digastric muscle. 



The submaxillary gland is ensheathed by the first layer of deep cervical 

 fascia. Observe the facial vein passing in front of the gland ; and the facial 

 artery, perforating the deep fascia and passing behind the gland, or even through 

 the same. 



WJiat nerves accompany the facial artery in its distribution to the face ? 



Sympathetic branches the nervi molles. They produce blushing and pallor 

 of the face. 



