354 



THE BRAIN 



still cover the dissector's own specimen and which will be 

 examined at a later stage. 



The main part of the brain is formed by two somewhat 

 hemispherical masses, called the cerebral hemispheres, which 

 are so large, in the human subject, that when the brain is 



Anterior central gyrus 



Central sulcus 

 Posterior central gyrus 

 Upper post-central sulcus 



Supra-marginal gyrus 

 Interparietal sulcus (proprius) 

 Angular &>' rus ^^ 

 Post-parietal gyrus ^jff^ 



Paroccipital sul 

 Arcus parieto- 

 occipitalis 

 Parieto-occipital ', 

 fissu 



Upper precentral sulcus 



I_ ower precentral sulcus 



Superior frontal sulcus 

 ; Superior frontal gyrus 



Middle frontal gyrus 



Calcarine 



fissure ' 

 Sulcus lunatus 



Transverse occipital 

 sulcus 



Olfactory bulb 

 Inferior frontal gyrt 

 Anterior horizontal brand 

 ateral fissure 



Anterior ascending branch 

 of lateral fissure 



.Posterior branch of lateral fissure 

 Superior temporal gyrus 



Olive of medulla oblongata 



Lateral occipital sulcus 

 Horizontal sulcus of cerebellum 



Right hemisphere of cerebellu 



Part of cerebellum which extends into foramen magnum 



FIG. 135. Lateral surface of Right Half of the Brain (semi-diagrammatic). 

 The horizontal dotted line completes the separation between the parietal 

 and temporal areas, and the oblique dotted line, which runs from the 

 parieto-occipital fissure to the pre-occipital notch, separates the occipital 

 from the parietal and temporal areas. 



examined from above they entirely conceal all the other parts 



(Fig. 137). 



The two hemispheres are connected together by (i) a 

 large transverse commissure called the corpus callosum (Fig. 

 136); (2) two smaller transverse commissures: (a) the 

 transverse fibres of the fornix and (b) the anterior com- 



