852 



THE NERVE SYSTEM 



of the optic chiasm and passing dorsad into the intercerehral cleft to the region 

 of the anterior commissure. 



Parallel to the mesal border of the orbital surface of each cerebral hemisphere lie 

 the olfactory tract and bulb, torn away from the h'la olfactoria as these pass through 

 the lamina cribrosa of the ethmoid. The olfactory tract may be traced to its 

 root area, the olfactory trigone, just frontad of the anterior perforated space. 



The superficial origin of nearly all of the cranial nerves may be seen upon the 

 basal aspect of the brain (Fig. 619). These nerves, their superficial attachments 

 to the brain, and the foramen of exit in the skull are enumerated in the following 

 table : 



TABULATION OF THE CRANIAL NERVES, THEIR SUPERFICIAL ATTACHMENTS TO 

 THE BRAIN, AND THE FORAMINA OF EXIT IN THE SKULL. 



NERVE. 



I. Olfactory fila. 

 II. Optic nerve. 



III. Oculomotor nerve. 



IV. Trochlear nerve. 

 V. Trigeminal nerve. 



VI. Abducent nerve. 

 VII. Facial nerve. 



VIII. Acoustic nerve. 



IX. Glossopharyngeal 

 nerve. 



X. Vagus nerve. 



XI. Spinal Accessory 

 nerve. 



XII. Hypoglossal nerve. 



SUPERFICIAL "ORIGIN" OR AT- FORAMEN OP EXIT FIJOM THK 

 TACHMENT TO THE BRAIN. SKULL. 



Olfactory bulb and tract. 

 Optic chiasm. 



Oculomotor groove along medial 

 border of cms. 



Ethmoidal cribrosa. 

 Optic foramen. 

 Sphenoidal fissure. 



Valve of Vieussens laterad of fren- Sphenoidal fissure, 

 ulum. 



Prelateral part of pons. 



Postpontile groove (prepyram- 

 idal part). 



Postpontile groove (laterad of 

 abducent nerve in preolivary 

 part). 



Postpontile groove (laterad of 

 facial nerve). 



Dorsolateral groove of medulla 

 oblongata. 



Dorsolateral groove of medulla 

 oblongata. 



(a) Encephalic part : Dorsolateral 

 groove of medulla oblongata. 



(b) Spinal part: Lateral column 

 of spinal cord, between ven- 

 tral and dorsal roots of cer- 

 vical nerves as far as the fifth 

 and sixth cervical nerves. 



Pyramido-olivary groove. 



() Ophthalmic ramus, superior 



orbital fissure. 

 (/>) Maxillary ramus. foramen " 



rotundum. - 



(r) Mandibular ramus, foramen | 



ovale. 



Sphenoidal fissure. 



Porus acusticus interims; meatus 

 acusticus internus ; facial canal ; 

 stylomastoid foramen, fiaii \ 



Porus acusticus int 



Jugular foramen. 

 Jugular foramen. 

 Jugular foramen. 



Canalis hypoglossi ("anterior 

 condylar foramen"). 



The olfactory, optic, and acoustic nerves are afferent or sensor nerves. 

 The trigeminal, glossopharyngeal, and vagus nerves are mixed m-r/rx. 



The oculomotor, trochlear, abducent, facial, spinal accessory, and hypoglossal nerves are 

 efferent or motor nerves. 



