THE ADRENALS 33 



power to overcome resistance, and secondly, a 

 still more important action. 



While the arteries of the great splanchnic reser- 

 voir and the superficial vessels of the skin are 

 contracted, the large deep vessels of the limbs are 

 dilated, and the blood flows freely from the centre 

 to the periphery ; thus the engorged areas round 

 the heart and lungs are bled into the limbs, 

 where hyperaemia can do no harm. This fact has 

 been proved by plethysmographic measurements. 

 Here again the manometer should be the guide 

 to the use of adrenalin plain or in combination. 

 The fact that the pulmonary arteries and the 

 cerebral are not constricted by adrenalin renders 

 its use practically free from danger, as far as those 

 organs are concerned. 



There is another use for adrenalin in haemate- 

 mesis : this may almost be regarded as an external 

 use, for the control of the haemorrhage is due to 

 the local action, and not to its action on the 

 circulation. In haemoptysis it is probably of no 

 use. In the various states known as neuras- 

 thenic, the whole gland extract is very valuable, 

 especiallyperhaps in low-pressure cases which form 

 the majority. It is often combined with other 

 gland extracts, such as thyroid, ovarian, orchitic, 

 and pituitary, and is known on the market as 

 3 



