102 



The Vertebrate Organ Systems 



Functionally the skull may be considered to consist of two main 

 regions. The cranium proper houses the brain, while the remainder 

 of the skull protects the sense organs and surrounds the upper por- 

 tion of the digestive tract. This latter part constitutes the bones of 

 the face. 



FRONTAL 



NASAL 

 LACRIMAL 

 MAXILLA 

 ZYGOMATIC 

 VECKEL'S CART 



MANDIBLE 



MAXILLAi 



PALATINE 



ZYGOMATIC 



PTERYGOI 

 PROCESS 



VOMER 



TEETH 



MANDIBULAR 

 ARTICULATION' 



STYLOID PROCESS 



AUDITORY MEATUS 



FRONTAL 

 SPHENOID 



MASTOID 

 PROCESS 



STYLOID PROCESS 

 A. 



PARIETAL 

 ■Wj / FORAMEN LACERUM 



TEMPORAL OCCIPITAL CON^LE^^ 



PARiETAL 

 ^CHONOBOCBANIUM 

 TYMPANIC FORAMEN MAGNUM 



OCEIPfTAL- 



TEWPORAL-JiJf 



NASAL CONCHA 



OCCIPITAL 

 TEMPORAL 

 (.lASTOlO PROCESS 

 'AUDITORY MEATUS 

 ZYGOMATIC ARCM 



Fig. 31. — The human skull. A, Embryonic membrane bones shown as black, 

 the cartilage cranium stippled; B-D, adult. B, basal view; C, frontal view; D, 

 lateral view. (From Neal and Rand: Chordate Anatomy, The Blakiston Company.) 



The mammalian skull has the dorsal part composed of the nasal 

 hone which protects the top of the nose, the frotital, parietal, and inter- 

 parietals. Posteriorly the skull is composed of the occipital complex, 

 and laterally of the premaxilla (absent in man), maxilla, and temporal 

 hones, and the sphenoidal complex. Laterally a portion of the temporal 

 and malar hones form the zygomatic arch. The orbit of the eye is 

 formed from elements of several bones, including the frontal, the maxilla, 

 the sphenoid, and the malar. Along the anterior wall of the orbit is the 



