160 THE POCKET ANATOMY 



branch, which connects it with the nerve above, and a descending 

 branch, which joins it to the nerve below. From the loop 

 between the and and 3rd nerves cutaneous branches are given 

 off to the head and neck, and from the union of the 3rd and 

 4th nerves superficial branches pass for the shoulder and 

 chest, together with muscular and communicating branches. 



SUPERFICIAL ASCENDING BRANCHES : 



Superficial cervical nerve : from loop between 2nd and 3rd 

 nerves, passes forwards over the middle of the sterno-mastoid, 

 perforates the cervical fascia, and divides beneath platysma 

 into : 



Ascending Branch : accompanies external jugular vein, com- 

 municates with the facial, and becomes cutaneous, supplies 

 front of upper half of neck. 



Descending : supplies integument as low as sternum. 



Great auricular: from and and 3rd. Winds round margin 

 of sterno-mastoid to reach parotid gland. Gives off: 



Facial : over parotid to integument of face. 



Auricular : to back part of pinna; communicates with pos- 

 terior auricular. 



Mastoid : supplying skin over mastoid process, joining with 

 posterior auricular of facial and small occipital. 



Small occipital: from and, ascends along posterior border 

 of sterno-mastoid to scalp, lying between ear and occipital 

 irtery ; supplies integument. 



Branch : 



Auricular : supplies integument of cranial surface of auricle. 



SUPERFICIAL DESCENDING BRANCH : from 3rd and 4th. 



Branches : 



Supra-sternal : to integument as far as middle line. 



Supra-clavicular : to integument over pectoral muscle, often 

 pierces clavicle. 



Supra-acromial : to integument of shoulder. 



DEEP BRANCHES (Internal) : 



Communicating : from loop between ist and and, joins 

 sympathetic, hypoglossal, and pneumogastric nerves. 



Communicans hypoglossi : from and and 3rd, form a loop 

 with descendens hypoglossi in front of carotid vessels. 



Muscular : to prevertebral muscles and through com- 

 munications with hypoglossal to genio- and thyro-hyoid. 



Phrenic : from 3rd and 4th, and a branch from the 5th ; 

 lies in front of scalenus anticus, descends inwards on it in 

 front of subclavian artery to enter the chest, having crossed 

 the internal mammary artery at origin, behind the subclavian 

 vein. In the thorax it descends in front of the root of the 



