306 ANATOMY IN A NUTSHELL. 



and behind the external jugular vein. It divides into three branches, (1) 

 auricular, which are three or four, anastomose with the auricular branches of 

 the facial and pneumogastric nerves. It is distributed to the integument of 

 the lobule and the lower part of the concha. (2) A mastoid branch which is 

 distributed to the integument over the mastoid process. This branch anasto- 

 moses with the small occipital and posterior auricular nerves. (3) The facial 

 branch crosses the parotid gland and supplies the integument covering the gland. 

 1: communicates with the seventh nerve in the gland. 



The transverse cervical nerve (superficialis colli) (Plate CCXVI) comes 

 from the second and third cervical nerves and passes around the posterior bor- 

 der of the Sterno-cleido-mastoid near its middle a little below the great auricular 

 nerve. It now passes across the neck beneath the integument, Platysma, and 

 externa] jugular vein (sometimes over the vein) to spread out into an ascending 

 and a descending branch. The ascending branch joins the cervical branches 

 from the facial nerve and supplies integument of the upper part of the neck as 

 high as the chin. The descending branch supplies the integument of the lower 

 half of the neck as far as the sternum. 



The communicating branches of the external division of the deep branches 

 are, (1) a communicating branch from the second cervical nerve to the Sterno- 

 cleido-mastoid. (2) Those from the third and fourth cervical nerves are dis- 

 tributed to the Trapezius. 



Muscular branches to (1) the Sterno-cleido-mastoid come from the second 

 cervical nerves and joins the spinal accessory nerve in the substance of the 

 muscle. (2) To the Scalenus medius, which comes from the third and fourth 

 cervical nerves and the loop between them. (3) To the Levator anguli scap- 

 ulae, which comes from the third, fourth, and sometimes the fifth cervical nerves. 

 It occasionally comes from the second also. (4) To the Trapezius which 

 coin,- from the third and fourth cervical nerves. 



The communicating branches of the internal division of the deep branches 

 aie. !l | gray rami communicantes from the superior cervical ganglion to each 

 of the first four cervical nerves, (2) a communicating branch to the pneumo- 

 gastric, also one to the hypoglossal, (3) communicating branches, which passto 

 the descendens hypoglossi from the second and third cervical nerves, (4) a 

 branch from the fourth cervical nerve to the fifth cervical nerve. 



.Muscular branches pass to the (1) Rectus capitis anticus minor, (2) Rectus 

 capitis anticus major, (3) Rectus capitis lateralis, (4) Longus colli. 



Communicans hypoglossi is formed by branches from the second and third 

 cervical nerves and pass down on the outer side of the internal jugular vein to 

 the middle of the neck where they join the descendens hypoglossi. 



This loop is called ansa hypoglossi. Branches are given off from this ansa 

 to the Sterno-hyoid, Sterno-thyroid, and Omo-hyoid. 



The phrenic nerve (internal respiratory of Bell) is derived from the third 

 fourth, and fifth cervical nerves, mainly from the fourth. As it descends in the 

 neck it has behind it the Scalenus anticus and in front of it (1) the Sterno-clei- 

 do-mastoid. (2) the posterior belly of the Omo-hyoid, (3) the transversalis colli 



