334 LABORATORY MANUAL OF HUMAN ANATOMY 



These five lobes are bounded by six fissures : 



(1) Fissure of Sylvius (fissura cerebri lateralis [Sylvii]). 



(2) Central sulcus of Rolando (sulcus centralis [Rolandi]) (0. T. fissure 



of Rolando). 



(3) Sulcus of cingulum (sulcus cinguli) (0. T. callosomarginal sulcus). 



(4) Parieto-occipital fissure (fissura parietooccipitalis) . 



(5) Collateral fissure (fissura collateralis}. 



(6) Circular sulcus of Reil (sulcus circularis [Reili]) (0. T. limiting 



sulcus of Reil). 



Frontal Lobe (Lobus frontalis). 



Find its posterior boundary on the convex surface by locating 

 the sulcus centralis [Rolandi] ; the latter is always between the 

 two parallel, obliquely placed, central gyri. What is the infe- 

 rior boundary of the frontal lobe on the convex surface? How 

 is it bounded on the medial surface of the hemisphere! In the 

 frontal lobe study the following : 



(a) Frontal pole (polus frontalis). 



(b) Anterior central gyrus (gyrus centralis anterior}. 



(c) Precentral sulcus (sulcus praecentralis) . 



(d) Superior frontal gyrus (gyrus frontalis superior). 



(e) Superior frontal sulcus (sulcus frontalis superior). 



(f) Middle frontal gyrus (gyrus frontalis medius). 



(fa) Superior part (pars superior). 



(fb) Inferior part (pars inferior). 



(g) Inferior frontal sulcus (sulcus frontalis inferior), 

 (h) Inferior frontal gyrus (gyrus frontalis inferior). 



(ha) Opercular part (pars opercularis) (on the left side this con- 

 stitutes the celebrated Broca's convolution, concerned in the 

 function of speech). 



(hb) Triangular part (pars triangularis). 

 (he) Orbital part (pars orbitalis). 

 (i) Straight gyrus (gyrus rectus). 

 (j) Olfactory sulcus (sulcus olfactorius) . 

 (k) Orbital gyri (gyri orbitales). 

 (I) Orbital sulci (sulci orbitales). 



Parietal Lobe (Lobus parietalis). 

 How is it bounded 



(a) On the convex surface? 



(b) On the medial surface? 



Examine on the convex surface 



(a) Posterior central gyrus (gyrus centralis posterior) (0. T. ascending 

 parietal convolution). 



