io88 



HUMAN ANATOMY. 



In recapitulation, the foregoing cerebellar lobes, with their component worm-segments and 

 associated hemisphere-tracts, and the intervening fissures may be followed in order, from the 

 anterior and superior end of the worm to its front and lower pole. Although not agreeing 

 with a morphological division, such grouping i is convenient as applied to the adult human 

 cerebellum. 



WORM 



Lingula 



The Lobes of the Cerebellum, 

 hemisphere 

 (Vinculum lingulae) 



Sulcus precentralis 



Lobulus centralis Ala lobuli centralis 



Sulcus postcentralis 



Culmen monticuli Lobulus lunatus anterior 



Sulcus preclivalis 



Clivus monticuli Lobulus lunatus posterior 



Sulcus postclivalis 



Folium cacuminis Lobulus postero-superior 



Sulcus Iwrizontalis 



Tuber vermis Lobulus postero-inferior 



Sulcus postpyratnidalis 



Pyramis Lobulus biventer 



Sulcus prepyraniidalis 



Uvula 



Tonsilla 



Sulcus postnodularis 



Nodulus 



Flocculus 



LOBE 

 Lobus lingulae 



Lobus centralis 



Lobus culminis 



Lobus clivi 



Lobus cacuminis 



Lobus tuberis 



Lobus pyramidis 



Lobus uvulae 



Lobus noduli 



Architecture of the Cerebellum. — With the exception of where the robust 

 peduncular collections of nerve-fibres enter the hemispheres and immediately above 

 the dorsal recess of the fourth ventricle, the cerebellum is everywhere covered by a 

 continuous superficial sheet of cortical gray matter which follows and encloses the sub- 

 divisions of the white core. The latter, as exposed in sagittal sections of the hemi- 

 sphere, is seen to be a compact central mass of white matter, from which stout stems 

 radiate into the various lobules. From these, the primary stems, secondary branches 

 penetrate the subdivisions of the lobules, and from the sides of these, in turn, smaller 

 tracts of white matter, the tertiary branches, enter the individual folia. Over these 

 ramifications of the white core, .the cortical gray matter stretches as a fairly uniform 

 layer, about 1.5 mm. thick, that follows the complexity of the folia and fissures. 

 The resulting arborization and the contrast between the white and gray matter are 

 particularly well shown in sections passing at right angles to the general direction of 

 the folia. This disposition is especially evident in median sagittal sections (Fig. 938), 

 where the less bulky medullary substance of the worm, also known as the corpus 

 trapezoideicm, and its radiating branches produce a striking picture, to which the 

 name, arbor vitcB cerebelli, is applied. 



The Internal Nuclei. — In addition to and unconnected with the cortical 

 layer, four paired masses of gray matter, the internal nuclei — one of considerable 

 size and three small — lie embedded within the white matter. 



The dentate nucleus (nucleus dentatus), or corpus dentatum, the largest and 

 most important of the internal nuclei, consists of a plicated sac of gray matter 

 (Fig. 951) and resembles in many respects the inferior olivary nucleus. Like the 

 latter, it is a crumpled thin lamina of gray matter which is folded on itself into a 

 pouch, enclosing white matter, through whose medially directed mouth, termed the 

 hilum, emerge many fibre-constituents of the superior cerebellar peduncle. The 

 dentate nucleus never encroaches upon the core of the worm, but lies embedded 

 within the anterior part of the median half of the hemisphere, with its long axis 



* Modified from Schafer and Thane in Quain's Anatomy, Tenth Edition. 



