460 



TEXT-BOOK OF PHYSIOLOGY. 



bk d 



cells are apparently wanting. Throughout the lobe there are numerous small 

 hyaline bodies which are apparently streaming upward to the ventricular 

 cavity. In view of the physiologic importance of this infundibular body or 

 parsnervosa, these hyaline masses are believed to represent an internal secretion 

 which passes upward through loose tissue channels toward, the infundibulum 

 to be discharged into the fluid of the third ventricle. If the stalk be 

 divided there is an accumulation of these bodies in the posterior lobe. 

 Both parts of the pituitary are well supplied with blood though from different 

 sources. 



Effects of Total Removal. The effects which were observed by the 

 earlier investigators to follow total removal of the hypophysis were not 

 always in accord by reason of the difference in the operative methods 



pursued, injuries to the brain, 

 infections, imperfect removals 

 as shown by post-mortem ex- 

 amination, etc. Some inves- 

 tigators claimed that after total 

 removal animals lived for long 

 periods and that therefore the 

 gland was not essential to life; 

 others* claimed, however, its 

 total removal was followed very 

 shortly by death preceded by a 

 series of characteristic symp- 

 toms and that therefore it was 

 absolutely essential to life. 

 The introduction of a new 



method of procedure for the re- 



FIG. 214. MESIAL SAGGITAL SECTION OF THE PIT- mova i f t u p hvnonhvsi* hv 



UITARY BODY OF THE MONKEY, a, Optic chiasm; 6, r in f . n yP 



process of the pars intermedia; c, third ventricle; d, Paulesco and its employment 



anterior lobe proper;/, posterior lobe or pars nervosa; by Gushing and his CO-WOrkers 



i, epithelium in vestment of the posterior lobe; &,epi the- -, , -, , , . , 



Hum of the pars intermedia passing over the neighbor- has led to results which are for 



ing brain mass; e, cleft. (After Herring.) the most part in general agree- 



ment. This method involves 



an approach to the gland through the temporal bone instead of through the 

 buccal cavity as was formerly the case. The temporal muscles are first 

 dissected away from the skull on both sides and reflected downward. 

 Large openings are made in the bone and dura of both sides. The temporal 

 lobe on one side is lifted up with a spoon-shaped spatula sufficiently large 

 to expose the hypophysis, hanging from the infundibulum. Owing to the 

 opposite opening in the skull, the opposite half of the cerebrum is displaced 

 and protruded so that injury to the brain from compression is prevented. 

 The gland can then be picked up with forceps and removed. Paulesco 

 reported that the total removal of the gland in 24 dogs resulted in death in 

 24 hours. In seven other animals the fatal result was postponed for variable 

 periods. One animal survived for five months and another for a year 

 without exhibiting any very characteristic symptoms. As a post-mortem 

 examination showed that the gland was only partially removed it was 

 assumed that the remaining portion had been sufficient to maintain life. 



