

CHAPTER VI 

 THE DISEASES OF THE HYPOPHYSIS [PITUITARY GLAND] 



Since Pierre Marie delineated the clinical picture of acromegaly and 

 placed it in an etiological relationship to the hypophysis, the literature on 

 the experimental research and clinical study of the hypophysis has grown 

 enormously. In spite of this fact there as yet prevails in our views as to the 

 pathogenesis of the clinical pictures concerned with the hypophysis very 

 little uniformity. The chiefest cause of this is that as yet we know but little 

 as to this organ's physiological significance, at least much less than we know 

 about the thyroid. The blame resides principally in the difficult accessibility 

 of the gland for experimental purposes, and further the fact that here we 

 have to do with two organs intimately bound together and enclosed in a rigid 

 bony cavity. A certain physiological independence of these two organs might 

 be expected from their, morphological and embryological independence. 

 Hence we may speak of a hypophysial apparatus showing certain analogies 

 with the thyroid apparatus (thyroid gland and parathyroid glands) and with 

 the corresponding suprarenal apparatus (cortex and chromaffin medulla), 

 hereafter to be described. The differentiation of the pathological mani- 

 festations accruing to the two systems is made more difficult than that of the 

 pathological manifestations affecting the other ductless gland groups because 

 on account of the enclosure in a rigid cavity an affection of one of the organs 

 seldom leaves the other entirely uninvolved. 



In an attempt to delimit and to explain the clinical pictures presented 

 by the hypophysial apparatus the following four points seem to begin to be 

 important, i. The characteristic typographical relations, 2. the embryo- 

 logical development, 3. a certain physiological independence, and 4. the mani- 

 fold analogies that exist between the glandular hypophysis and the thyroid 

 gland. 



Anatomy and Embryology. The normal hypophysis of man weighs on 

 the average somewhat more than 0.5 gm. It consists in a glandular anterior 

 lobe and a nervous posterior lobe. Both lie in the sella turcica, into which 

 cavity the dura penetrates through the foramen sellae turcicae and surrounds 

 them both in common. From the anterior lobe a small process projects 

 forward in the so-called peduncle of the hypophysis while the posterior lobe 

 is directly in communication with the brain by means of the infundibulum. 

 A tapering cleft, the recessus infundibuli, in communication with the third 

 ventricle, penetrates deeply into the peduncle. 



The following scheme after Erdheim shows these relations: Ch. = 



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