HEAD AND ANTERIOR CERVICAL STRUCTURES. 51 



The Veins of the Medulla and Pons, 663. (649) 



Medulla oblongata. 



Pons. 



The vessels and the remaining portion of the membranes should now be removed from the base of the 

 brain. The superficial structures of the base and the superficial origin of each of the cranial nerves 

 should then be noted. 



Base of the Brain : Dissection, 719-20. (703-4) 

 The cerebral hemispheres, 720-1. (704-5) 

 Anterior pole, posterior. 

 Fissures, or sulci. 

 Convolutions, or gyri. 

 Super-external surface. 

 Internal surface. 

 Inferior, surface. 

 Fissures, 721-2-3. (705-6-7) 



(a) Great longitudinal fissure. Great transverse fissure. 

 () Complete and incomplete. 

 Interlobar fissures : 



Parieto-occipital fissure : 



Internal parietooccipital or internal perpendicular fissure. 

 External parieto-occipital fissure. 

 Fissure of Sylvius : 



Posterior limb. 



Ascending limb. 



Anterior limb. 



Fissure of Rolando, or central sulcus. 



Superior genu. Inferior genu. 



Lobes of the Cerebral Hemispheres with Fissures and Convolutions, 723-4. 

 (707-8) 



Frontal. Parietal. Occipital. Temporo-sphenoidal. Central lobe or 

 Island of Reil. Falciform lobe. Olfactory lobe, rhinencephalon. 



Frontal lobe, 724-5. (7089) 



Surfaces : Super-external or frontal. 

 Inferior, or orbital. 

 Internal, or mesial. 

 Frontal surface, orbital margin. 

 Praecentral sulcus. 



Superior frontal fissure. Sulcus fronto-marginalis. 

 Inferior frontal fissure. 

 Ascending frontal convolution. 

 Superior frontal convolution. 

 Middle frontal convolution. 

 Inferior frontal convolution : 

 Pars orbitalis. 

 Pars triangularis. 

 Pars basilaris. 

 ' Orbital surface : 

 Tridate fissure. 

 Olfactory or straight sulci. 

 Orbital convolutions: 



Internal. Anterior. Posterior. 

 Straight convolution, or gyrus rectus. 

 Parietal lobe, sulcus subparietalis, 725-6. (70910) 

 Intraparietal fissure. Ramus occipitalis. 

 Ascending parietal convolution. 

 Superior parietal lobe. 

 Supramarginal convolution. 

 Angular gyrus. 



