THE HEAD AND NECK 1059 



The great occipital nerve is the internal branch of the posterior 

 primary division of the second cervical ner\'e. It pierces the upper 

 part of the complexus muscle, and sometimes the trapezius, about 

 \ inch from the middle line. It then turns upwards, with an 

 inclination outwards, and accompanies the occipital artery to the 

 cranial integument, lying on the inner side of that vessel. Its 

 branches are long, and have an extensive distribution, reaching 

 as far as the vertex of the skull. Externally it commimicates with 

 the small occipital nerve, and internally with the least occipital. 



The least or third occipital nerve is a small offset from the internal 

 branch of the posterior primary division of the third cervical 

 nerve. Having pierced the trapezius, it ascends internal to the 

 great occipital nerve, with which it communicates, and has a 

 limited distribution to the occipital integument inside that nerve. 



The internal branches of the posterior primary divisions of the 

 third, fourth, and fifth cervical nerves appear through the trapezius 

 close to the middle line, and turn outwards to supply the skin of 

 the back of the neck, that of the third furnishing, as just stated, 

 the least occipital nerve. 



The small occipital nerve is one of the ascending superficial 

 branches of the cervical plexus, and arises from the anterior primary 

 division of the second cervical nerve, sometimes receiving a 

 branch from that of the third. It appears at the posterior border 

 of the stemo-cleido-mastoid muscle, and ascends along that border 

 to the occipital region. Here it divides into mastoid and occipital 

 branches, which supply the skin of the mastoid, outer part of the 

 occipital, and adjacent portion of the parietal, regions. It furnishes 

 an auricular branch to the skin of the inner surface of the auricle, 

 and it communicates with the great occipital, the mastoid and 

 auricular branches of the great auricular, and the posterior auricular 

 branch of the facial. The small occipital nerve is sometimes 

 double, and in these cases one portion of it usually pierces the 

 anterior border of the trapezius. 



The great auricular nerve, like the small occipital, is one of the 

 ascending superficial branches of the cervical plexus, and arises 

 by two roots from the anterior primary divisions of the second 

 and third cervical nerves. It turns round the posterior border 

 of the stemo-cleido-mastoid immediately below the small occipital 

 nerve, and passes upwards and forwards upon that muscle towards 

 the lobule of the auricle, on approaching which it divides into 

 mastoid, auricular, and facial branches. The mastoid branch is 

 distributed to the skin over the mastoid region ; the auricular 

 branch supplies the skin of the inner surface of the auricle, and 

 sends one or two twigs through the cartilage of the auricle to the 

 skin covering its outer surface ; and the facial branch is distributed 

 to the skin over the parotid gland. The mastoid and auricular 

 branches communicate with the small occipital and posterior 

 auricular nerves, and the facial branch commimicates in the parotid 

 gland with the cervico-facial division of the facial nerve. 



