INTERNAL SECRETIONS AND THE DUCTLESS GLANDS 281 



organs produce substances that are essential to the main- 

 tenance of life. One of these is the thyroid gland which is 

 situated in the fore part of the neck under the larynx. 

 Complete removal of the thyroid results in death, which, 

 however, may be obviated if the substance secreted by 

 this organ is given to the patient. This substance con- 

 tains iodine and is now a remedy that is regularly kept at 

 drug stores. There is a peculiar disease called cretinism, 

 caused by impairment of the thyroid, which is associated 

 with certain bodily abnormalities and especially lack of 

 mental development. Administration of thyroid extract 

 has a wonderful curative power in such 

 cases, and it often converts a child who 

 is backward to the point of idiocy into a 

 bright and happy little person. There 

 was simply supplied the internal secretion 

 necessary for normal development which 

 its own body failed to furnish in sufficient 

 amount. Another disease, goiter, is _ 



caused by an abnormal enlargement of thyroid gland; L, 

 the thyroid. 



Other glands that produce a substance essential to life 

 are the adrenals or suprarenal bodies, small glands imme- 

 diately over the kidneys. Preparations made from these 

 glands (adrenalin, epinephrin) have the property of con- 

 tracting the blood vessels of a part to which they are 

 applied and they are therefore used in minor surgical 

 operations to prevent bleeding;. 



The pancreas in addition to the pancreatic juice dis- 

 charged into the intestine secretes a substance that has to 

 do directly or indirectly with the metabolism of sugar. 

 Removal of the pancreas results in the accumulation of 

 sugar in the blood (diabetes) and eventually in death. 

 If, however, a small part of the pancreas is grafted in 



