ENDOCRINE GLANDS AND THEIR FUNCTIONS 201 



lowering of blood pressure and body temperature, and decline in 

 urine secretion and heart rate. Lack of cortin is said to disturb 

 the salt relation in the blood (particularly sodium chloride and 

 potassium), the water metabolism and redistribution in the body, 

 the metabolism (especially absorption) of intermediate carbohy- 

 drates and fats, and milk production in females (at least in cats). 



The Pituitary Gland 



The pituitary gland in the human being is a body weighing about 0.5 

 Gm., lodged in a depression at the base of the brain. It consists of two 

 principal parts: the anterior lobe and the posterior lobe. These 

 two portions have distinct functions. The vital importance of this 

 body was not realized for many years, but a series of observations 

 has placed it in a position oi such importance that it has been 

 referred to as the regulator of the glandular system. The pituitary 

 gland is now known to be the source of a number of hormones, and 

 their functions are so closely connected with those of other endo- 

 crine secretions that they apparently have a part in all hormonal 

 processes of the body. 



The secretions of the anterior lobe of the pituitary affect the 

 growth and development of the organism in general, the general 

 metabolism of the body, the development of the sex organs, and 

 work with other hormones in controlling additional processes, in- 

 efficiency in the anterior lobe, furnishing the body with either too 

 much or too little of the growth-promoting hormone (phj^rone) re- 

 sults in the production of giants or dwarfs. A decreased supply 

 of the hormone in an immature individual, if the condition is not 

 remedied by administration of the hormonal extract, retards the 

 growth of the body and may cause a complete cessation of growth. 

 The dwarfs of the circus furnish examples of this unfortunate con- 

 dition, although not all dwarfism must be thought due to this cause. 

 For example, the cretin described previously is the result of thyroid 

 disorder and is usually a mental dwarf as w^ell as a dwarf in body, 

 while dwarfism resulting from deficient phyrone is accompanied in 

 most cases by a normal mental development. 



An overfunctional anterior pituitary results in a marked increase 

 in the growth of bones, although the general development of the 

 individual thus affected may be symmetrical and the physiological 

 processes may be normal in every respect. Cases of this type are 

 commonly seen. One such instance may be cited in which a nine- 



