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SECTIOlN^ Y 



THE i^EKYOUS SYSTEM 



By H. ST. JOHN BROOKS, M.D., B.Ch., D.Sc, B.A. 

 Revised for Second Edition by ARTHUE ROBINSON, M.D., M.R.C.S.England 



LE(.TURER ON ANATOMY IN THE MIDDLESEX HOSPITAL MEDICAL SCHOOL; EXAMINER IN ANATOMY FOR THE CONJOINT 



BOARD OF ENGLAND 



^''FUEOLOGY 



nVTEUROLOGY is that branch of Anatomy which deals with the nervous system. 

 I_\ It treats of the brain and s{)inal cord, constituting the cerebro-spinal axis 

 or central nervous system ; the cranial and spinal nerves, or peripheral 

 nervous system, and the sympathetic system, which is intimately connected 

 with the two former and closely associated with the vessels, viscera, and glands. 

 The study of the nervous system (of the brain in particular) is greatly facilitated 

 by a knowledge of its mode of development and by Comparative Anatomy. It 



Fig. 401. — Diagrammatic Sagittal Section of a Vertebrate Brain. (After Huxley.) 



CORPORA qUADRIGEMINA MESEXCEPHALOX PIXEAL BODY 



CEREBELL UM 



MEDULLA 

 OBLOXGA TA 



POXa VAROLII 



LA TERA L 



VEXTRICLE 

 (JEREBRA L 



HEMISPHERE 

 CORPUS 



STRIA TUM 

 RH/XEX- 



CEPHALOX 



CRURA CEREBRI 



OPTIC I riTUITARY 



THALAMUS \ BODY 



THA LA MENCEPHA LON 



FOR AM EX OF MOXRO 



4. fourth ventricle ; k, aqueduct of Sylvius ; 3, third ventricle. 



is not our purpose to enter into these sultjects here; but an examination of the 

 two diagrams (figs. 401 and 402), which are based upon Embryology and Com- 

 parative Anatomy, will familiarise the student with the plan upon which the 

 brain is laid down, and form a key to the complicated structure of the adult human 

 brain. 



At an early period of embryonic life the cerebro-spinal axis consists simply of 

 a thin walled tube, the neural tube, Avhich becomes enlarged at the ce]»halicend of 

 the bodv. Constrictions appear on this enlarged cephalic end, dividing it into three 



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