,2 OUTLINES OF ANATOMY. 



Dura mater : 



Inner or supporting lamina. 

 Pacchionian glands, 716. (700) 

 Deep veins of the head and neck, 655. (642) 

 A cranial sinus, 711. (695) 



Venous sinuses of the cranium, 656-7. (643) 



Open the superior longitudinal sinus by a median incision ; trace it from the foramen caecum to the 

 internal occipital protuberance. 



Superior longitudinal sinus, 657-8. (643-4-5) 

 Torcular Herophili. 



Turn off the lateral portions of the dura mater in the manner indicated, and note the cerebral veins, 

 Dissection, 711. (694-5) 



Subdural space, 715. (699) 

 Veins of the brain, 66 1. (648) 



Cerebral veins. 



Cortical, hemispherical, or superficial veins. 



Superior cortical veins. 

 Falx Cerebri, 714. (698) 



Divide the falx cerebri in front and throw it backward and out of the longitudinal fissure, and carefully 

 remove the brain; to do this, tilt the head back, carefully raise the frontal and olfactory lobes from the 

 anterior fossa, divide the optic nerves and the ophthalmic arteries just back of the optic foramen. 

 Divide the internal carotid arteries also. In the median line behind the optic commissure, the pituitary- 

 body lies in the sella turcica, covered by the dura mater, but connected with the brain by the infundibu- 

 lum. Divide the infundibulum close to the dura mater. The third pair of nerves will next be exposed, 

 and should be carefully divided midway between the brain and the dura mater. Proceed thus, dividing 

 each pair of cranial nerves as they are displayed. Divide the tentorium near its attached border and 

 push it back ; the medulla and cerebellum can then be raised. Cut the spinal cord low down in the 

 canal and divide the vertebral arteries where they emerge from the dura mater. The brain can then be 

 removed, and should be placed in spirit or Miiller's fluid and properly hardened before dissection. The 

 dura mater lining the base of the cranium should then be examined. The cranial nerves should be 

 exposed and traced to place of exit from the cranial cavity. Each of the venous sinuses should belaid 

 open with the point of the knife and their communications noted. Finally, the pituitary should be 

 exposed and removed and its structure studied. 



The dura mater, diaphragma sellae, 712. (696) 

 Tentorium Cerebelli, 714-15. (698-9) 



Upper surface. Under surface. Free border. Attached border. 

 Falx Cerebelli, 715. (699) 

 Diaphragma sellas, 715. (699) 

 The Cranial Nerves, 786-7-8. (769-70) 

 Superficial and deep origins. 

 General distribution : 



Nerves of special sense. 

 Motor nerves. 

 Mixed. 



In the following list the place of exit of each cranial nerve is stated. The superficial and deep origins 

 will be studied later. A statement of the course of each nerve will be found in the general descrip- 

 tion, to which the reference is given. The distribution of each nerve will be gradually developed as 

 the dissection proceeds. 



(Modified from Holden.) 

 The Cranial Nerves: 



First, or olfactory nerve, 788. (770) 



From the under aspect of the bulh proceed about twenty branches, which 

 pass through foramina in the cribriform plate of the ethmoid bone. 

 Second, or optic nerve, 790. (772) 



Passes through the optic foramen into the orbit, accompanied by ophthalmic 

 artery. 

 Third, or oculo-motor nerve, 791. (774) 



Passes through the dura mater close behind the anterior clinoid process, 

 traverses the outer wall of the cavernous sinus, and enters the orbit through 

 the sphenoidal fissure. 



