262 ANATOMY AND PHYSIOLOGY 



During pregnancy the areola acquires a deeper color (which is 

 permanent) and the glands of Montgomery are enlarged. 



At this time the blood supply of the gland increases, the glands 

 become large, and changes occur in the lining of the tubules, which 

 result in the secretion of milk. This is perfected soon after the 

 end of pregnancy. 



The first fluid which is drawn from the breast is called colos- 

 trum; it is yellow (from the presence of colostrum corpuscles), 

 alkaline, rich in proteins and salts but not in sugar nor in fat. ' It 

 contains a substance which acts as a laxative for the infant. 



The secretion of milk is influenced by the diet of the mother and 

 may be modified in both quantity and quality by food selection. 

 A still greater effect is produced by the condition of her nervous 

 systems; it is well known that fright or anger, or intense emotion, 

 may so affect the milk as to make it injurious to the infant. 

 Fatigue, worry, loss of sleep, etc., are all to be avoided by the 

 nursing mother. 



Human milk contains a small quantity of starch splitting 

 (amylolytic) enzyme; it is possible, therefore, to exert some effect 

 upon the starch content of barley water in the food of the young 

 infant so that some nourishment may be gained from it. 



The milk may differ in the two breasts of the same person. 



Menstruation is accompanied by a diminution of lactose and 

 an increase of fat and casein. 



The milk of the pregnant woman is poor in quality, especially 

 in fat. 



Clinical note. Certain drugs taken by the mother will be 

 eliminated through the milk in sufficient degree to affect the 

 child; as beer, or bromides, salines and other cathartics; strychnia, 

 arsenic, etc. 



Surgical note. Mammary abscess is caused by infection 

 through a break or fissure in the skin of the nipple, the pus form- 

 ing between the lobes of the gland. Post-mammary abscess is in 

 the fascia behind the gland. 



THE DUCTLESS GLANDS OR THE ENDOCRIN SYSTEM 



This system includes the ductless glands and the chromaffin 

 tissues. 



