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HANDBOOK OF ANATOMY 



clavicle by dividing into three parts sternal, clavicular, and 

 acromial. 



(2) The Muscular branches of the plexus are in two sets 

 internal and external, according to their relation to the sterno- 

 mastoid muscle. 



External branches passing outwards to posterior triangle 



Attrahens Auriculam 



Attollens Auriculam . 



Retrahens Auriculam 



Occipitalis- 

 Great Occipital Nerve- 



Levator Anguli Scap 



Great Auricular Nerve .. 

 Spinal Accessory Nerve .- 

 Branches from Third and Fourtn 

 Cervical Nerves to Trapezius 

 Scalenus Mediu 



Supra-acromial Nerve 

 Trapezius.. 



Small Occipital Nerve- - 

 Splenius Capiti 



_.Frontalis 



] Oi bicularis Palpebrarum 



Levator Labii 

 Superioris Alaeque Nasi 

 .Levator Labii Superioris 

 Zygomaticus Minor 

 ?^l.Zygomaticus Major 



Masseter 



. Orbicularis Oris 



..Depressor Labii Inferioris 

 --Depressor Anguli Oris 

 Levator Menti 



Anterior Belly of Digastric 



Sterno-hyoid 



'Anterior Belly of Omo-hyoid 



. Sterno-cleido-mastoid 



. Superficial Cervical Nerve 



..Suprasternal Nerve 

 .JSupraclavicular Nerve 



Scalenus Anticus 



/ i 



Posterior Belly of Omo-hyoid bubclavian Artery (third part) 



FIG. 63. NERVES IN POSTERIOR TRIANGLE OB' NECK. 



supply sterno-mastoid, levator scapulse, trapezius and the 

 scaleni, and communicate with the spinal accessory nerve. 



Internal branches passing inwards to anterior triangle supply 

 the prevertebral muscles, genio-hyoid, and infrahyoid muscles, 



