SECTION IV 

 RESPIRATION 



LESSON XVI 



1. Changes in the Chest during Breathing 



(a) With a tape, measure the circumference of the chest of a 

 companion in full expiration and in full inspiration and record the 

 result. 



(6) With the cyrtometer provided take a tracing of a section of 

 the chest in expiration and in inspiration and compare them, 

 measuring and recording the diameters (i) close up under the 

 armpits ; (ii) at the base of the lungs, about the level of the eighth 

 or ninth rib. (Keep the records.) 



(c) Now place the middle finger of the left hand flat on the sixth 

 right intercostal space in front of the chest and strike it firmly with 

 the middle finger of the right hand. Do this during expiration and 

 during inspiration, and note any difference in the sound produced. 

 The air- containing lung yields a resonant note, the solid liver yields 

 a dull note. Record your conclusion as to the vertical extent of 

 the lung in expiration and in inspiration. 



(Read Text Book on the Movements of the Chest.) 



2. Changes in the Air breathed 



(1) Breathe upon a piece of cool clean glass. Note what happens 

 and draw a conclusion as to the saturation of expired air. 



(2) Breathe out repeatedly through the vessel of lime water 

 provided, and note the change produced. What is this due to ? 



(3) Breathe out repeatedly through the weak solution of potassium 

 permanganate provided, and note the change produced. What 

 is this due to ? 



(4) A bell-jar, fitted with a cork through which passes a glass tube 

 to which is attached a piece of rubber tubing with a glass mouth- 

 piece is provided. It rests on a glass plate lubricated with vaseline. 

 Place a lighted candle under the bell- jar and breathe the air of the 

 jar through the tube. Note the changes in the flame and explain 

 them. 



3. Sounds produced during Breathing 



With a stethoscope listen (a) over the windpipe and (6) over the 



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