The limit between the head and the neck is made along the margin and angle of the mandible up to the apex of the mastoid process and further along the superior nuchal line up to protuberantia occipitalis externa.
The head has the cranial and the facial part; the limit between them goes along the supra-orbital margin, the zygomatic bone and the zygomatic arch up to the external acoustic meatus (fig. 4.1).
Fig. 4.1. The limit between the cranial and facial parts of the skull (red dotted line), and between the calvaria and the cranial base (yellow dotted line)
CRANIAL PART OF HEAD
The cranial part of the head consists of the calvaria (the skull-cap) and the cranial base, basis cranii. The calvaria and the base are separated from one another by the frontonasal suture, the supra-orbital margin, the superior margin of the zygomatic arch, the base of the mastoid process, and further by the superior nuchal line and protuberantia occipitalis externa.
CALVARIA, CALVARIA
In the calvaria there are the following regions: single - the frontal, parietal and occipital ones, and paired - the temporal, auricular and mastoid ones. The similarity of structure of the first three regions makes it possible to unite them in one, the frontal-parietal-occipital region.
FRONTAL-PARIETAL-OCCIPITAL REGION,
REGIO FRONTOPARIETOOCCIPITALIS
Surface landmarks. The supra-orbital margin, the tuber occipitalis, the tragus, the external acoustic meatus.
Limits. The anterior is the supra-orbital margin, margo supraorbitalis; the posterior is the external occipital protuberance, protuberantia occipitalis externa, and the superior nuchal line, linea nuchae superior going horizontally at either side of the protuberance; at the flanks - the initial part of the m. temporalis corresponding on the skull to the superior temporal line.