THE CEREBRUM 



421 



It commences below the anterior end of the corpus callosum 

 and runs at first forwards and upwards and then backwards, 

 parallel with the supero-medial border of the hemisphere, to 

 a point somewhat behind the upper end of the posterior 

 central gyrus, where it turns upwards, cuts the supero-medial 

 border, and terminates on the supero-lateral surface of the 

 hemisphere. It separates the gyrus cinguli, which embraces 

 the anterior and upper parts of the corpus callosum, from the 

 superior frontal gyrus and the upper ends of the anterior and 

 the posterior central gyri (Figs. 159, 160). 



Massa intermedia 



Thalamus 

 Paracentral lobule 

 Central sulcus (Rolandi) 

 Sulcus cinguli 



Splenium of corpus callosum 

 Subparietal sulcus 



Precuneus 



Parieto-occipita 

 fissure 



Cuneus^ 



Interventricular foramen 

 Callosal sulcus 



Gyrus cinguli above callosal sulcus 

 Superior frontal gyrus 

 Fornix 



Septum pellucidum 



Gyrus cingul 



i I 



\ 



fissure L ingual gy; 



Calcarine fissure 

 Calcarine fissure below isthmus of gyr 



fornicatus ,' I ' j 

 Lamina quadrigemina 



Pineal body : J 



Aquaeductus cerebri j 



Pedunculus cerebri 



Pons 

 Oculrj-motor nerve Mamillary body 



Superior 

 frontal gyrus 



,| Genu of corpus callosum 



| Subcallosal gyrus 

 | Paraterminal body 

 | Anterior commissure 

 \ Optic chiasma 



\ Infundibuk 

 Tuber cinereun 



lary body 



FIG. 159. Medial surface of Left Hemisphere (semi-diagrammatic). 



Sulcus Subparietalis. Behind the posterior end of the 

 sulcus cinguli, and sometimes continuous with it, is the sub- 

 parietal sulcus. It separates the medial part of the superior 

 parietal lobule, which is called the precuneus, from the 

 posterior part of the gyrus cinguli (Figs. 159, 160). 



The Gyri of the Medial Surface of the Hemisphere. The 

 gyri on the medial surface of the hemisphere are the superior 

 frontal gyrus ; the upper ends of the anterior and the posterior 

 central gyri, the precuneus, the cuneus, part of the lingual 

 gyrus, the gyrus cinguli, and part of the gyrus rectus. 



