REMOVAL OF THE BRAIN 



205 



Sinus Sagittalis Superior (O.T. Superior Longitudinal). 

 Open into this venous channel by running the knife through 

 its upper wall from behind forwards (Figs. 85 and 86). It 

 begins anteriorly at the crista galli of the ethmoid bone, 

 where it not infrequently communicates with the veins in 

 the nasal cavity through the foramen caecum. It extends 



Frontal air sinus 



it edge of superior 



sagittal sinus ;_ 



' 



Cerebral vein 



Arachnoid 

 vering cereb 



vein 



_ Dura mater 



Anterior branch of 

 mid. meningeal arte 

 and accompanying 

 vein 



Arachnoideal 

 granulation 



Posterior bram 

 of mid. meningi 

 artery with veil 



)peningof a superi 

 erebral vein 



Cerebral vei 



FIG. 85. Superior Sagittal Sinus ; Dura Mater ; Middle Meningeal Artery 

 and Veins ; Arachnoidea and Superior Cerebral Veins. 



posteriorly, grooving the cranial vault in the median plane, to 

 the internal occipital protuberance, on the right aspect of 

 which it becomes continuous with the right transverse sinus 

 (O.T. lateral). Its lumen, which is triangular in cross-section, 

 is very small anteriorly, but expands greatly posteriorly. On 

 either side of the sinus, and opening into it, are a number of 

 clefts between the two layers of the dura mater ; these are 



