198 



LABORATORY MANUAL OF HUMAN ANATOMY 



Dura Mater of Brain (Dura mater encephali). (Vide Figs. 83, 84.) 

 Wipe the surface clean with a moist sponge. Study 



(a) Middle meningeal artery (A. meningea media). 



(b) Arachnoideal granulations (granulationes arachnoideales 



oni]) (0. T. Pacchionian granulations). 



[Pacchi- 



Place the head nearly upright and support it by blocks. 

 Make two sagittal incisions through the dura mater, one on each 

 side of the superior sagittal sinus, along its whole length. From 



FIG. 83. 



-skull 



_ Dura mat. encephali 



Arachnoidea encephali 

 "-Pia mater encephali 



- - - Cav. subarachnoid. 



\\\x 



.\ \ A r .v .' G y rus cerebri 



\V x ' ^ 



\\\\ 



lyvA.^ X Cav. subarachnoid. 



k\ V 



The meninges. Schematic section passing through a sulcus cerebri. The pia mater encephali 

 in red. (From Poirier et Charpy, Traite d'Anat. hum., Paris, 1899, t. iii., 1, p. 96, Fig. 69.) 



the middle of each incision make a cut .lateralward through the 

 dura as far down as the cut margin of the skull ; reflect the flaps 

 of dura forward and lateralward and backward and lateralward 

 respectively. The subdural space (cavum subdurale) has now 

 been opened up. Compare the inner surface of the dura mater 

 with the outer. 



The arachnoid of the brain (arachnoidea encephali) is non- 

 vascular and transparent. Through it the vessels of the pia 

 mater of the brain (pia mater encephali) are visible. 



Superior Sagittal Sinus 



The veins on the surface of the brain can be seen running 

 towards the superior sagittal sinus (sinus sagittalis superior) 

 (O. T. superior longitudinal sinus). This sinus should be opened 

 throughout its whole length with a sharp knife or scissors. 

 Observe in it the network-like bands (0. T. chordae Willisi). 



Cut through the superior veins of the cerebrum which empty 



