. Cunningham's Text-book of anatomy. Anatomy. INTERNAL STEUCTURE OF MEDULLA OBLONGATA AND PONS. 561 GRACILE NUCL. NUCLEUS OF TRACTUS SPINALIS N. TRIGEMINI. Fig. 496.—Diagram, sides of the medulla oblongata ; (3) external arcuate fibres coming from the arcuate nuclei; and (4) olivo-cerebellar fibres. The fasciculus spinocerebellaris extends upwards from the lateral funiculus of the medulla spinalis. In the lateral district of the medulla oblongata it occupies a similar position; but before the olive is reached it inclines backwards, crosses the posterior lateral furrow and passes
. Cunningham's Text-book of anatomy. Anatomy. INTERNAL STEUCTURE OF MEDULLA OBLONGATA AND PONS. 561 GRACILE NUCL. NUCLEUS OF TRACTUS SPINALIS N. TRIGEMINI. Fig. 496.—Diagram, sides of the medulla oblongata ; (3) external arcuate fibres coming from the arcuate nuclei; and (4) olivo-cerebellar fibres. The fasciculus spinocerebellaris extends upwards from the lateral funiculus of the medulla spinalis. In the lateral district of the medulla oblongata it occupies a similar position; but before the olive is reached it inclines backwards, crosses the posterior lateral furrow and passes obliquely upwards into the restiform body. As its fibres diverge backwards, they pass over and cover up the tractus spinalis of the trigemi- nal nerve and its nucleus, thus shut- ting them out from the surface. The fibres of the fasciculus spinocere- bellaris, in the first instance, enter into the lateral or superficial part of the restiform body. Bruce lias shown that the fibres of the spino-cerebellar tract ultimately lie in the centre of the restiform body, forming as it were its central core, and that, in the cere- bellum, they can be traced to the superior vermis. Which shows in part the fibres which enter into the constitution of the restiform body. The posterior external arcuate fibres take origin from the gracile and cuneate nuclei, and enter the superficial part of the restiform body of the same side. The anterior external arcuate fibres proceed from the inferior portions of the gracile and cuneate nuclei of the opposite side. It can easily be determined that, after decussating in the median plane, all the internal arcuate fibres which arise from these nuclei do not enter the lemniscus medialis. A large proportion of them gain the surface by sweeping round the medial aspect of the pyramid in the anterior median fissure. Many of them gain the surface by piercing the pyramid or by passing out between it and the olive. These fibres constitute the anterior external arcua
Size: 1562px × 1599px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectanatomy, bookyear1914
