3S ATLAS AND TEXT-BOOK OP HUMAN ANATOMY. 



of the zygomatic bone, and the temporal ridge commences at the zygomatic process of the frontal 

 bone and passes backward in a curved manner over the frontal and parietal bones. 



Behind the frontal bone is seen almost the entire parietal bone. It is limited anteriorly 

 bv the coronal suture and is separated from the occipital bone posteriorly by the lambdoid suture. 

 Its lower border articulates with the greater wing of the sphenoid by the sphenoparietal sut: 

 with the squamous portion of the temporal bone by the squamosal suture, and with the mastoid 

 portion of the temporal bone by the parietomastoid suture. 



The onlv portion of the occipital bone visible in the lateral view of the skull is its squamous 

 portion, which is separated from the mastoid process of the temporal bone by the occipitomastoid 

 suture. 



Below the frontal and parietal bones, the temporal surface of the greater wing of the sphenoid 

 is visible. It is separated from the zygomatic bone anteriorly by the sphenozygomatic 

 and from the squamous portion of the temporal bone posteriorly by the s phenosquamosal suture. 



The first portion of the temporal bone to attract attention in the lateral aspect of the skull 

 is the squamous portion, from which a long process, the zygomatic process, passes almost hori- 

 zontally forward to articulate with the short temporal process of the zygomatic bone by the 

 zygomatico-tem poral suture; the two processes together forming the zygoma or zygomatic arch. 

 The origin of the zygomatic process of the temporal bone marks the termination of the inferior 

 temporal line as it passes from the parietal to the temporal bone. 



Below the inferior temporal line there is upon the lateral surface of the skull a slightly 

 depressed area, the planum temporale, formed by the temporal and parietal bones, the greater 

 wing of the sphenoid, and a small portion of the frontal bone. In the zygomatic region the 

 planum temporale deepens into the temporal fossa. 



The portion of the temporal line situated upon the temporal bone forms approximately 

 the anterior boundary of a second portion of the temporal bone visible in the lateral view of 

 the skull, the mastoid portion, which derives its name from a strong conical protuberance, the 

 mastoid process. 



A third portion of the temporal bone to be seen in the lateral cranial region is the tympanic 

 portion, and is situated immediately below the root of the zygoma, forming the outer and lower 

 circumference of the large opening of the bony external auditory meatus {meatus acusticus 

 extern u 



In looking at the skull from the side, the malar surface of the zygomatic bone is directed 

 toward the observer. In the lateral aspect of the maxilla there may be observed (as in the 

 anterior view) the anterior nasal spine, the frontal process, the nasomaxillary suture by which it 

 articulates with the nasal bones, and the alveolar process, which is directed toward the simi- 

 larly named portion of the mandible. 



In the lower jaw we see the body with the mental foramen, and almost at right angles with 

 the body, the ramus, the upper portion of which is divided by a deep notch, the sigmoid notch, 

 into two processes, the coronoid and the condyloid processes. The articular surface of the 

 condyloid process rests in a fossa of the temporal bone situated below the root of the zygoma, 

 the mandibular or glenoid jossa. 



