122 
MAMMALIAN ANATOMY 
E. RESPIRATORY SOUNDS. 
By means of the phonendoscope adjusted with the end of the 
rod applied (i) to the region of the trachea, (2) over the apex of 
one of the lungs (beneath the clavicle), and (3) to the back at one 
side of the midline at about the level of the fourth intercostal 
space, listen to the sounds accompanying respiration. Try to 
distinguish (1) sounds of the air moving through larynx and 
trachea and (2) vesicular murmurs which are due to the opening 
up of the bronchioles and alveoli during inspiration, and which 
die away during the latter part of expiration. The subject should 
be loosely and thinly dressed. 
F. SPIROMETER MEASUREMENTS OF THE VOLUMES 
OF AIR CONCERNED IN RESPIRATION. 
At least five trials should be made for each measurement and 
the results recorded and averaged. Each student should make the 
records from his own respiration; two students may , however, con¬ 
veniently assist each other in obtaining the records. Record the 
measurements in cubic centimeters (1 liter = 1000 cu. cm.). 
1. The tidal volume, the amount breathed in and out in a 
normal respiratory act. Determine by measuring the amount of 
air breathed out in a normal expiration following a normal 
inspiration. 
2. The complemental volume, the amount which is taken in 
during a forced inspiration in excess of the tidal volume. Deter¬ 
mine by measuring the amount breathed out in a normal expiration 
after a forced inspiration and deducting the tidal volume already 
obtained. 
3. The supplemental volume, the amount which may be 
expelled by a forced expiration in excess of the tidal volume. 
Determine by measuring the amount of air breathed out in a forced 
expiration following a normal inspiration and deducting the tidal 
volume already obtained. 
4. The vital capacity (complemental plus tidal plus supple¬ 
mental volumes). Determine by measuring the amount of air 
breathed out by a forced expiration following a forced inspiration. 
Check by comparison with the sum of 1, 2, and 3. 
