. The practice of medicine; a text-book for practitioners and students, with special reference to diagnosis and treatment . and,lowest of all, the thumb. The center for the leg lies in the uppermost part CEREBRAL LOCALIZATION 947 of the central convolutions, but mostly in the paracentral lobule. Mostanterior is the hip, next the knee and ankle, next the great toe, the centerfor the movement of which surrounds the upper end of the fissure of Ro-lando; still further back are the centers for the small toes. The centerfor the trunk is situated in the precentral convolution between those forthe upp
. The practice of medicine; a text-book for practitioners and students, with special reference to diagnosis and treatment . and,lowest of all, the thumb. The center for the leg lies in the uppermost part CEREBRAL LOCALIZATION 947 of the central convolutions, but mostly in the paracentral lobule. Mostanterior is the hip, next the knee and ankle, next the great toe, the centerfor the movement of which surrounds the upper end of the fissure of Ro-lando; still further back are the centers for the small toes. The centerfor the trunk is situated in the precentral convolution between those forthe upper and lower limbs. The different regions are not sharply defined,but merge into one another. As to the so-called muscular sense, it has been believed that it residesalso in the motor area, while there have been those who have claimed forit also a separate and different localization. M. Allen Starr and A. have reported a case of injury with symptoms which go to provethe latter view and to show that the seat of the muscular sense is a spotin the brain about at the junction of the superior and inferior parietal. Cyrus i Fig. i6i.—Aspect of the Median Surface of the Cerebrum as it appears when the Two Hem-ispheres are Separated—{after Ecker).The gyri and fissures are indicated by the lettering. convolutions, clearly posterior to the posterior central convolution, andmany investigations have shown that the so-called muscular sense isprobably largely represented in the parietal lobe. These cortical motor areas are united with spinal centers by nerve-fiberswhich proceed from cell to cell in each, without connection with interven-ing cells. Their route is through the white matter of the hemispheres,where they form the corona radiata, the fibers of which converge to theinternal capsule which lies between the optic thalamus and the caudatenucleus on the inside, and the lenticular nucleus on the outside. (SeeFig. i6i.) The anterior portion of the posterior limb of the capsul
Size: 1951px × 1280px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookidpracticeofme, bookyear1913
