CHAPTER X 

 THE BLOOD AND CIRCULATORY ORGANS 



THE BLOOD 



The blood is the most important fluid in the body. It not only 

 carries food to every part, but bears waste matters to those 

 organs which can dispose of them in the form of excretions. It 

 consists of a clear yellowish fluid called plasma and small round 

 cells (invisible to the naked eye) called corpuscles (little bodies), 

 which float in the plasma. The corpuscles are of two sorts, red 

 and white. 



FIG. 1 1 6. CORPUSCLES OF BLOOD, AS SEEN UNDER THE MICROSCOPE. 

 Four white ones are shown. The red ones have a tendency to form rows. (Funke 



and Brubaker.) 



It is convenient to follow the usage common in clinical work and speak of 

 them as red and white cells. 



Blood has a characteristic odor which varies in different animals. 



The temperature of the blood is about 100 F. 



The reaction is alkaline. 



The red cells (erythrocytes) are non-nucleated, flexible and 

 elastic. They are very numerous, numbering 4,000,000 to 

 4,500,000 in a cubic millimeter. They measure about -^^ of 

 an inch in diameter, and their shape has been usually described 



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