THE EXTERIOR OF THE SKULL 



69 



THE EXTERIOR OF THE SKULL 



The skull, when viewed from above, presents an oval outline; the posterior part is 

 broader than the anterior. The bones seen in this view are the frontal, parietals, 

 and the interparietal portion of the occipital. In a skull of average width the 

 zygomata come into view, but in very broad skulls they are obscured. 



The sutures of the vertex are: — 



The metopic, which is, in most skulls, merely a median fissure in the frontal 

 bone just above the glabella ; occasionally it involves the whole length of the bone. 

 It is due to the persistence of the fissure normally separating the two halves of tlie 

 bone in the infant: 



Fig. 79. — The Skull. (Norma lateralis.) 



The sagittal is situated between the two parietals, and extends from the bregina 

 to the lambda. 



The coronal lies between the frontal and parietals, and extends from pterion to 

 pterion. 



The lambdoid is formed by the parietals and interparietal portion of the occi- 

 pital. It extends from asterion to asterion. 



The occipital suture is only present when the interparietal exists as a separate 

 element (fig. 35 ). 



The more important regions are: — 



The bregma, which indicates the situation of the anterior fontanelle, and 

 marks the confluence of the coronal, the sagittal, and, when present, the metopic 

 sutures. 



The lambda, where the sagittal enters the lambdoid suture; it marks the situa- 

 tion of the posterior fontanelle. 



