RESPIRATION 



IOI 



ir. Give advantages of full breathing over shallow breathing. 



12. How may a flat chest and round shoulders be a cause of con- 

 sumption ? How may these deformities be corrected ? 



13. Give general directions for applying artificial respiration. 



PRACTICAL WORK 



Examine a dissectible model of the chest and its contents (Fig. 49). 

 Note the relative size of the two lungs and their position with reference 

 to the heart and diaphragm. Compare the side to side and vertical 

 diameters of the cavity. Trace the air tubes from the trachea to their 

 smallest divisions. 



Observation of Lungs (Optional). Secure from a butcher the lungs 

 of a sheep, calf, or hog. The windpipe and heart should be left attached 

 and the specimen kept in a moist condition until used. Demonstrate 

 the trachea, bronchi, and the bronchial tubes, and the general arrange- 

 ment of pulmonary arteries and veins. Examine the pleura and show 

 lightness of lung tissue by floating a piece on water. 



To show the Changes that Air undergoes in the Lungs. i . Fill a 

 quart jar even full of water. Place a piece of cardboard over its mouth 

 and invert, without spilling, in a pan of water. 

 Inserting a tube under the jar, blow into it 

 air that has been held as long as possible 

 in the lungs. When filled with air, remove 

 the jar from the pan, keeping the top well 

 covered. Slipping the cover slightly to one 

 side, insert a burning splinter and observe 

 that the flame is extinguished. This proves 

 the absence of sufficient oxygen to support 

 combustion. Pour in a little limewater 1 and 

 shake to mix with the air. The change of 

 the limewater to a milky white color proves 

 the presence of carbon dioxide. 



FIG. 50. Apparatus 

 for showing changes which 

 air undergoes while in the 

 lungs. 



2. The effects illustrated in experiment i may be shown in a some- 

 what more striking manner as follows : Fill two bottles of the same 



1 To prepare Hmewater some small lumps of fresh lime (either slacked or 

 unslacked) are added to a large bottle of water and thoroughly shaken. This is 

 put aside until the lime all settles to the bottom and the water above is perfectly 

 clear. This is now ready for use and may be poured off as needed. When the 

 supply is exhausted add more water and shake again. 



