THE CIRCULATION 101 



CHAPTER VII. ' * > 5 . * .1 



T-HE CIRCULATION, 



Tlie Blood Its Plasma and Corpuscles Coagulation of the Blood The 

 Uses of the Blood Transfusion Change of Color The Organs of 

 the Circulation The Heart, Arteries, and Veins The Cavities 

 and Valves of the Heart Its Vital Energy Passage of the Blood 

 through tfie Heart The Frequency and Activity of its Movements 

 The Pulse The Spygmograph The Capillary Blood-vessels T/ie 

 Rate of the Circulation Assimilation Injuries to the Blood-vessels. 



1. The Blood. Every living organism of the higher 

 sort, whether animal or vegetable, requires for the main- 

 tenance of life and activity, a circulatory fluid, by which 

 nutriment is distributed to all its parts. In plants, this 

 fluid is the sap; in insects, it is a watery and colorless 

 blood; in reptiles and fishes, it is red but cold blood; 

 while in the nobler animals and man, it is the red and 

 warm blood. 



2. The blood is the most important, as it is the most 

 abundant, fluid of the body ; and upon its presence, under 

 certain definite conditions, life depends. On this account 

 it is frequently, and very properly, termed "the vital 

 fluid." The importance of the blood, as essential to life, 

 was recognized in the earliest writings. In the narration 

 of the death of the murdered Abel, it is written, "the voice 

 of his blood crieth from the ground." In the Mosaic law, 

 proclaimed over thirty centuries ago, the Israelites were 

 forbidden to eat food that contained blood, for the reason 

 that "the life of the flesh is in the blood." With the 

 exception of a few tissues, such as the hair, the nails, 

 and the cornea of the eye, blood everywhere pervades the 

 body, as may be proven by puncturing any part with a 



1. What is required by every living organism? In plants ? Insects? Reptiles*? 

 Man? 



2. Importance and abundance of blood? Dependence of life ? Abel? Mosaic 

 law ? In what part of the body is blood not found ? Quantity of blood in the body ? 



