OTHER GLANDS 199 



the adrenal cortex. It is almost always fatal. Removal of the 

 adrenals in lower animals always results in death. 



The commercial product, adrenaline, is used to prevent or check 

 bleeding. It causes a temporary constriction of blood vessels in 

 the area, which results in checking the flow of blood. In opera- 

 tions for the removal of tonsils, surgeons often spray the patient's 

 throat with an adrenaline solution before the operation, in order 

 to prevent a great loss of blood. This is known as the bloodless 

 operation. 



The pancreas. The pancreas is a digestive gland secreting 

 pancreatic juice which passes through a duct to the small intes- 

 tines, where it acts upon the food particles coming from the 

 stomach. The pancreas also acts as a ductless gland. Certain 

 cells embedded in the pancreas, called the islands of Langerhans, 

 produce a secretion called insulin which contains a hormone that 

 is absorbed directly into the blood. This hormone stimulates 

 the liver to give up its glycogen. At the same time, it accelerates 

 the oxidation of sugar in the tissue cells. Thus sugar is removed 

 from the blood and the body. If the islands of Langerhans lose 

 the ability to produce this secretion, the sugar is not used and 

 some of the extra sugar remains in the blood and some is excreted 

 with the urine. The individual develops a disease known as 

 diabetes. Dr. F. G. Banting and his associates discovered (in 

 1922) that the insulin obtained from the normal pancreas of 

 animals would produce a marked decrease in diabetes symp- 

 toms. Much suffering has already been lessened through this dis- 

 covery. Insulin is available for treatment of diabetes although 

 it is not considered a cure. Its use must be continual, since as 

 yet no method has been discovered for stimulating the defective 

 condition of the organ so that it can make its own insulin. 



Other glands. The thymus is a small gland in the neck below 

 the thyroid. It probably has a close relation to growth and 

 possibly to sexual development. Experiments seem to prove 



