15^4 A MANUAL OF ANATOMY 



The cervical part of the trapezius is to be dissected, and its anterior border 

 clearly defined, with the spinal accessory nerve and branches of the third 

 and fourth cervical nerves passing beneath it. The posterior portion of the 

 upper part of the sterno-cleido-mastoid is also to be clearly defined. The 

 interval between the trapezius and the sterno-cleido-mastoid, partially visible 

 in this position of the subject, is the posterior triangle. Within it are to be 

 partially dissected the following structures : a small angle of the complexus 

 muscle pierced by the great occipital nerve, provided the trapezius is not 

 well developed ; a portion of the splenius muscle, fiat and broad, and directed 

 upwards and outwards ; and a portion of the levator anguli scapulae. 



The occipitalis muscle is next to be dissected, and the epicranial aponeurosis, 

 upon which its fibres end, is to be displayed. The close connection between 

 this aponeurosis and the superficial fascia is to be noted, whereas it is only 

 loosely connected to the subjacent periosteum or pericranium. Behind the 

 auricle the retrahens auriculam muscle is to be shown passing between the 

 mastoid process and the convexity of the concha. Lying deeply in the hollow 

 between the mastoid process and the auricle careful dissection will bring into 

 view the posterior auricular nerve and artery, both of which are to be fol- 

 lowed to their distribution. The posterior auricular vein is of importance, 

 because, in conjunction with the posterior division of the temporo-maxillary 

 vein, it forms the external jugular vein. Above the auricle the attoUens 

 auriculam muscle is to be shown, lying upon the temporal fascia. In front 

 of the auricle, and continuous with the preceding muscle, will be found the 

 attrahens auriculam. The latter two muscles will be found to receive twigs 

 from the temporo-facial division of the facial nerve. 



Frontal Region. — The dissection of the frontal region is next to be over- 

 taken, the head being well raised upon a block. The frontalis muscle and 

 front part of the epicranial aponeurosis are to be dissected. The supra- 

 orbital nerve, of large size, is to be carefully displayed. It will be found 

 ascending in line with the junction of the inner third and outer two-thirds 

 ■of the supra-orbital arch, in company with the supra-orbital artery, and it lies 

 at first beneath the upper part of the orbicularis palpebrarum and the frontalis 

 muscles. Its twigs to the upper eyelid are to be looked for, and its main 

 branches are to be followed towards the vertex of the skull. The supra- 

 trochlear nerve, of small size, will be found internal to the supra-orbital, and 

 in line with the inner canthus of the eye. It is accompanied by the frontal 

 artery. The supra-orbital vein is to be shown passing downwards and 

 inwards to join the frontal vein in the region of the inner canthus, the resultant 

 vessel being the angular vein, which is the commencement of the facial vein. 

 A communicating vessel is to be looked for passing from the supra-orbital 

 vein to the supra-orbital notch, after traversing which it communicates with 

 the superior ophthalmic vein within the orbit. 



Temporal Region. — The attollens and attrahens auriculam muscles have 

 been already referred to. Directly in front of the tragus of the auricle there 

 will be found the auriculo-temporal nerve and the superficial temporal artery 

 and vein. The nerve lies between the tragus and the artery, and its 

 meatal, anterior auricular, and temporal branches are to be shown, the first 

 two sets of branches requiring considerable care in their display. The 

 temporal branches of the temporo-facial division of the facial nerve are 

 to be kept in view at this stage. The superficial temporal artery, in two 

 divisions, anterior and posterior, is to be dissected, and special attention is to 

 be given to the tortuous anterior division, which is of some surgical impor- 

 tance. The temporal branch of the temporo-malar or orbital nerve (from 

 the superior maxillary division of the fifth cranial nerve) will be met with 

 piercing the temporal fascia about i inch above the anterior part of the 

 zygoma, and close behind the marginal process on the temporal border of 

 the malar bone. Its cutaneous distribution is somewhat limited. 



The temporal fascia, or aponeurosis, is next to be dissected. In the region 

 of the zygomatic arch it will be found to consist of two laminae, between 

 which, in addition to fat, will be found the orbital branch of the superficial 

 temporal artery on its way to the outer part of the orbicularis palpebrarum 



