pineal glcmct 



- -parccth/roioCs 



t>ryroid:._ 

 thymus 



392 FOODS CIRCULATED AND USED IN THE BODY 



PROBLEM n. WHAT ARE THE FUNCTIONS OF SOME OF 

 THE ENDOCRINE GLANDS? 



The endocrine or ductless glands and their secretions. In 



addition to all the functions already mentioned, the blood has 



another very wonder- 

 ful work. We have 

 already mentioned 

 the hormones (from 

 the Greek word hor- 

 mon, meaning " to 

 excite"). These 

 chemical activators, 

 produced by the en- 

 docrine or ductless 

 glands in various 

 parts of the body, go 

 into the blood stream, 

 and stimulate another 

 organ or organs in the 

 body. The blood is 

 the only means of 

 communication be- 

 tween these glands 

 and the tissues on 

 which their hormones 

 act. Scientists are 

 just beginning to ap- 

 preciate the tre- 

 mendous influence on 

 life of some of these glands, among which are the thyroid and 

 parathyroid, small glands located in the neck; the adrenals 

 (ad-re'nal), tiny glands, closely attached to the kidneys; the 

 pituitary body, at the base of the brain; parts of the pancreas; 

 and parts of the egg-producing and sperm-producing organs, the 

 ovaries and testes. The thymus and spleen, although not true 

 glands, are often included with those mentioned above. 



X- f~ liver- 



^ „J-^pocncreocs 



X— -I— -spleew. 

 |— occtrenccl-, 



"kidney 



The approximate positions of the endocrine glands are 

 indicated in the diagram. 



