174 PRACTICAL PHYSIOLOGY 



CHAPTER XLIII. 

 RESPIRATION. 



Examination of the Chest of Man. Much can be learned by simple 

 methods of examination, and it is of the greatest importance that 

 the medical student should rely more upon his sight, hearing and 

 touch, than upon the graphic records obtained with different forms 

 of apparatus. 



Inspection. The chest of a man stripped to the waist is examined 

 and the following points are noted : (i) The shape, whether the thorax is 

 strongly built and symmetrical, (ii) its mobility, whether the two sides 

 move equally. The condition of the abdominal wall should then 

 be examined, and attention paid to the development of its muscles 

 and the movements during respiration. 



The measurement round the chest of an adult man is about 35 inches 

 and can be taken with a tape. The increase in circumference produced 

 by inspiration is about 2 to 3 inches. It is impossible, however, to 

 determine by such measurements whether a man has a good " wind " 

 or not. A well-developed chest generally means that a man has 

 lived an active life and has a good heart and lungs, but great variations 

 are found in the shape of the chest of healthy men. The true test 

 of a man's heart and lungs is whether he can respond to the demands 

 of muscular exercise without undue breathlessness and distress. 

 Even this test must be applied with intelligence, for the man may 

 be under-fed, and may have led a very sedentary life. 



A graphic record of the shape of the chest in different planes can 

 be obtained with the cyrtometer. This simple instrument consists of 

 two pieces of narrow lead piping hinged by a piece of rubber tubing. 

 The hinge is placed over the vertebral column and the lead tubing 

 is moulded round the sides of the chest in a horizonal plane ; the 

 cyrtometer is then opened, removed from the chest, placed in position 

 on a sheet of paper, and its outline traced with a pencil. 



The movements of the chest and abdomen should be observed and 

 their relationship to inspiration and expiration determined. Some 

 subjects show marked abdominal or diaphragmatic breathing, others 

 breathe more by the thorax. In women the movement of the upper 

 part of the chest is greater than in men ; the causes of this differ- 

 ence are to be ascribed to the constriction of the abdomen and lower 

 portion of the thorax by corsets and to the greater mobility of the 

 thorax, due to the fact that in civilised countries the women do less 



