244 INTERNAL SECRETION 



The heart (with vagi cut) is slowed, but individual beats 

 are augmented. Blood-pressure is increased by vaso- 

 constriction, but the effect is not repeated on a second 

 dose. 



All plain muscle is contracted, the most striking effect 

 being upon the uterus. 



The renal cells are stimulated— causing diuresis. 



A secretion of milk occurs, due, however, not to activity 

 of the glands but to squeezing out of the milk already 

 present by contraction of the muscle fibres. 



The assimilation hmit of sugar is lowered. 



Extract of the pars nervosa is more effective in pro- 

 ducing the above effects than extract of the pars intermedia. 



Extract of the pars anterior is inactive. 



Disorders of the Pituitary. — Two conditions are associated 

 with affections of the pituitary— acromegaly and dystrophia 

 adiposo-genitalis. 



In acromegaly there is an enlargement of the face, hands 

 and feet, due chiefly to great hypertrophy of the bones. 

 There is abnormal muscular development, thickening of 

 the skin, overgrowth of hair, and sometimes diminished 

 carbohydrate tolerance. This condition is attributed by 

 Gushing to superactivity of the pituitary. If the dis- 

 turbance sets in before ossification is completed, all the 

 long bones undergo a great increase in length — pituitary 

 gigantism. 



Dystrophia adiposo-genitalis is beheved to be due to 

 insufiiciency of the pituitary, the signs being the reverse 

 of those found in acromegaly. Growth and sexual develop- 

 ment are defective. The mind is lethargic and the tem- 

 perature subnormal. There is marked adiposity and an 

 increased sugar tolerance, 200-300 grms. of glucose being 

 absorbed without glycosuria occurring. 



In this condition administration of an extract of the 

 anterior lobe reheves only the subnormal temperature, 

 while extract of the posterior lobe only raises the low 

 blood-pressure and lowers the sugar-tolerance. 



