50 
LABORATORY EXERCISES 
trunk? What is the character of the collar-bones? Why are they 
so easily broken? In the human skeleton study the arch of the 
foot. Upon what does the weight of the body rest? What is the 
use of this arrangement? What has happened when the condition 
known as flat foot ” is present? 
V. What purposes, in relation to the body, does the skeleton 
serve? 
VI. If it has been possible to compare the skeletons of two or 
more different groups of vertebrates, what similarities have you 
found with regard to the skull? The vertebral column? The 
limbs (appendages)? 
EXERCISE 53 
THE ORGANS OF THE CHEST AND ABDOMEN 
OF THE HUMAN 
I. The chief regions of the human body are the head and trunk. 
The upper part of the trunk cavity is the chest) the lower part is 
the abdomen. (Use the manikin or chart. If neither is available, 
refer to the diagram in the text. See Waggoner, Fig. 140.) Note 
the character of the chest walls; the thickness. Compare the walls 
of the abdomen with those of the chest. How do the internal 
organs lie in the body cavity with relation to one another? What 
are the character and shape of the diaphragm, the partition which 
separates the chest and abdomen? What is its position with rela¬ 
tion to the body walls? To what is it attached? Specify the loca¬ 
tion on your own body. 
II. The Chest. What organs lie in the chek cavity? What is 
their relation to one another? To the diaphragm? Note the 
gullet, the esophagus, which enters from the throat region. In 
front of this is the trachea, whose branches lead to the lungs. Note 
the aorta, the artery which curves upward and back from the 
heart. Follow its course. 
III. The Abdomen. Note the liver, the large organ toward the 
right and just beneath the diaphragm. Below this, and to the 
