52 
LABORATORY EXERCISES 
Swallow. Note the sound which occurs. Explain this sound. 
How does food in its passage to the gullet, which lies beyond the 
pharynx, cross over the opening of the windpipe? Locate the 
epiglottis. How are substances, being swallowed, prevented from 
entering the nasal cavity? What happens when you laugh just 
as you swallow? 
Note carefully the location of the tonsils and the region where 
enlarged adenoids often develop. 
EXERCISE 55 
THE CIRCULATION OF MAN 
I. On a manikin or a chart locate the heart with reference to the 
lungs, the ribs, and the breastbone. Think where it is in your 
own body. Place your hand over the location where the heart 
touches the chest wall. What are the shape and size of the heart? 
In the figure in the text (see Waggoner, Figs. 147 and 149) note 
the divisions of the heart — the right and left auricles and the 
right and left ventricles. Find the relation of the pulmonary artery 
and pulmonary veins to heart and lungs, respectively. Locate 
the aorta, the great artery leaving the left ventricle. Trace its 
course. Find the caval veins which return the blood to the right 
auricle. Note carefully the distribution of blood vessels in the 
lungs and in the various parts of the digestive system. 
II. Note the distribution of veins on your arm and hand. Hold 
your arm on a level with your shoulder or higher. Again note the 
veins. Next allow the arm to hang at your side. What difference 
is there in the appearance of the veins under these three conditions? 
Explain. Compress some spot on the arm or wrist. What is the 
result? Rub the forearm toward the fingers. What is the result? 
What is the position of the veins with regard to the skin? Explain 
the results of the above experiments. How does the movement of 
the muscles affect the veins which are near them? How does 
muscular action aid the circulation of the blood? On the manikin 
or chart determine the positions of veins and arteries as related 
