54 ANATOMY 



One often encounters islets of cortical cells imbedded in the 

 medulla, particularly in those species in which the division of 

 cortex and medulla is not sharply defined. 



The adrenal medulla of man and the higher anthrapoid apes 

 is a post-natal development. During early infancy the ex- 

 tra-adrenal chromaphil tissues degenerate simultaneously with 

 the rapid growth of the medulla which occurs at this period. 



PATHOLOGICAL CHANGES IN THE MICROSCOPIC APPEARANCE OF 

 THE ADRENALS 



The microscopic appearance of the adrenals is markedly 

 affected by a number of pathological conditions. There is a 

 loss of lipids with the formation of vacuoles in certain infec- 

 tious diseases, particularly diphtheria. Similar changes occur 

 following endogenous toxicoses as in peritonitis or burns, and 

 following metabolic disturbances as in diabetes or pernicious 

 anemia. In septic processes, as in scarlet fever, there is often 

 an edema of the cortex with the accumulation of an exudate 

 between the cells of the fascicular layer. 21 - 156 • 157 



In chronic starvation, as Landau 376 first showed, there is an 

 increase in the cholesterol store of the cortex, probably due to 

 the liberation of this substance from the catabolized cells. 

 The changes in the appearance of the adrenals with the state 

 of nutrition must be taken into account before ascribing any 

 observed abnormality to other causes. Thus the changes 

 ascribed to epilepsy, dementia praecox, and other mental dis- 

 eases can be explained solely on the basis of the altered nutri- 

 tive condition of the patients suffering from these diseases. 



Although the characteristic doubly refractive substance of 

 the cortex increases with rest, vanishes in exhaustion, and un- 

 dergoes characteristic changes in other conditions, 181 it cannot 

 be an essential factor in cortical activity, for it is not present 

 in the adrenal of the sheep and certain other animal species. 

 In pathological states, exhausting changes of the medulla and 

 cortex, as noted histologically, move in close parallelism. 



