22 B. G. HOSKINS 



The Endocrin Organs and Old Age 



Whether endocrin factors play a significant part in the onset of the 

 changes characteristic of senility has been debated but without any very 

 convincing evidence having been adduced. Senescence is marked by a 

 series of anatomical changes of a regressive or degenerative nature, such 

 as might theoretically result from a precedent failure of the "regulators 

 of metabolism," or, more specifically, of the stimulating and sustaining 

 hormones. 



Such changes occur in every organ and tissue of the body. The tissues 

 either assume atrophic forms or are replaced by those of other character 

 which are functionally less efficient. In the nervous system both the 

 central and peripheral structures are affected. The nerve cells, as well 

 as the medullary fibers, show atrophic changes with increased density and 

 loss of lipoids. The muscles waste away, and the heart tends to become 

 more or less fibrotic, but may show hypertrophy compensatory to changes 

 in other parts of the circulatory system. The bones lose a portion of their 

 organic matter, becoming brittle and to some extent showing osteoporosis. 

 Ligaments and tendons lose their elasticity and show general wasting. 

 The synovial structures likewise deteriorate. The skin changes charac- 

 teristic of old age are known to all. Pigmentation, atrophy of se- 

 baceous and sudoriparous glands and general wasting of both cutaneous 

 and subcutaneous tissues occur. The hair generally becomes dry and 

 thin but may show excessive growth in certain situations, in the eyebrows, 

 at the external auditory meatus, or the anterior nares. In women more 

 or less hair growth on the upper lip and chin is not uncommon. In the 

 viscera general atrophic and fibrotic changes are common. The spleen, 

 for instance, may bo reduced to one-half its normal size. The prostate, 

 however, tends to enlarge through overgrowth of connective tissue. The 

 liability of the blood vessels to become hardened and infiltrated with 

 lime salts is well known. 



Extensive as are- these anatomical alterations, the physical debility of 

 old age is, according to Thewliss, even greater and in many instances 

 not explicable upon a purely anatomical basis. 



Ooodpasture, in ID 18, made an extensive report upon the changes 

 incident to senescence. His work was based upon a study of fifty 

 He has evolved a conception that "with a continued increase in 

 structural intricacy, incident to aging, the body cells gradually lose their 

 metabolic equilibrium, so that the ultimate conclusion of progressive cell 

 differentiation is death. But it is possible for many cells to return to a 

 more simple form in which special function is absent or subordinate to 

 liTowth and division." This process of elimination of structural differ- 

 ences is called "de-differentiation." A de-differentiated cell may differ- 



