Fig. 92.— Diagrammatic representation of the lower portion of the human bulb and spinal cord. 



The cord is divided into Lts four regions : 1, medulla cervicalis; _'. medulla dorsalis : 3, medulla lum- 

 balis; 1, medulla sacralis. Within each region the spinal segments bear Roman numbers. On the left 

 side of the diagram the locality supplied by the sensory (afferent) neurones is indicated by one or more 

 words and these latter are connected with the bulb or the segments of the cord at tin- levels at which 

 the nerves enter. The afferent character is indicated by the arrow-tip on the lines of referenci 



On the right-hand side the names of muscles or groups of muscles are given, and to them arc drawn 

 reference lines which start from the segments of the cord in which the cell-bodies of origin have been 

 Located. 



Within the cord itself, the designations for several reflex centres are inscribed in the segment where 

 the mechanism is localized. For example. Reflexus scapularis. Centrum eilio-spinale, Reflexus epigas- 

 tricus, Reflexus abdominalis. Reflexu> cremastericus, Reflexus patellaris, Reflexus tendo Achillis, Cen- 

 trum vesieale, Centrum analc (the last two on the left side of the diagram). (From Iccrnes yrtnoloyicx, 

 Striimpell and Jakob.) 



