APPLIED ANATOMY. 



Cerebral Softening. This occurs in the young from embolism; it then affects 

 the cortex, but the more common variety is caused by thrombosis in arteries which 

 are diseased, usually in the aged. The part farthest from the source of blood 

 supply is the most apt to suffer, therefore we find it occurring most frequently in 

 the anterior capsuloganglionic region, just above the usual site of apoplexy (Fig. 34). 

 The affected area will be seen to be most remote from both the cortical and basal blood 

 supply. The perforating arteries supplying this region are in the nature of terminal 

 branches and do not anastomose to any extent either with each other or with the 

 branches coming from the cortex, hence their occlusion inflicts irreparable damage. 



Apoplexy. By apoplexy is meant the rupture of a blood-vessel with conse- 

 quent extravasation of blood, either in or on the brain. It may occur in any portion 

 of the brain, and either from the arteries of the base, or from the smaller arteries of 



Lateral ventricle 



Caudate nucleus 



Internal capsule, 

 anterior limb 



Lenticular nucleus 

 Claustrum 



Internal capsule, 

 posterior limb 



Thalamus 



Corpora quadrigemina 



Lateral ventricle, 

 inferior horn 



Septum hicidutn 

 Fornix anterior pillar 



FIG. 37. Horizontal section of the brain, showing the internal capsule and its relation to the lateral ventricles. 



the cortex. The former is the more frequent. The arteries that most often rupture 

 are the branches of the middle cerebral which enter the anterior perforated space, 

 especially its outer portion. One of the largest of these anterolateral arteries, as has 

 already been mentioned, known as the lenticulostriate, has been called by Charcot 

 the artery of cerebral hemorrhage. 



The portions of the brain usually affected are the posterior portion of the len- 

 ticular nucleus, internal capsule, and surrounding parts. 



Figure 35 is a medial section of the brain, giving a lateral view of the ventricles. 



Figure 36 is a horizontal transverse section of the brain, opening up the ventri- 

 cles. In front are seen the two lateral ventricles, separated by the septum lucidum. 

 The cavity shown in the septum lucidum is the so-called fifth ventricle. The round 

 body bulging into the lateral ventricle and forming its floor is the caudate nucleus 

 portion of the corpus striatum. The third ventricle is posterior and below the lateral 

 ventricles, and extends from the septum lucidum in front to the posterior pillars of 

 the fornix behind. It extends from side to side as one large cavity with no median 

 partition. Bulging into the third ventricle on each side are the {optic} thalami. 

 They are separated from the corpora striata by some white fibres, the ttznia semicircu- 

 laris. To the inner side of the taenia semicircularis is seen the choroid plexus, which 



