138 A NA TOM Y A ND PH YSIOL OGY FOR NURSES 



respiration may become obstructed and the blood become 

 overcharged with the poison. When the liver is inflamed 

 or its ducts obstructed, the constituents of the bile are re- 

 tained in the blood or pass into it by transudation. In 

 acute nephritis urea is, in like manner, retained within the 

 system and induces the gravest symptoms. 



Of the morbid products which find their way into the 

 blood, one of the most harmful is the germ of suppuration, 

 which, under certain circumstances, is absorbed from the 

 veins or from suppurating surfaces. Extraneous matters 

 such as toxins, germs, or both, may be introduced by the 

 stomach, skin, and lungs, or more directly by penetrat- 

 ing wounds. 



The quantity of blood is increased by food and in 

 plethora. It is diminished in hemorrhage and absti- 

 nence. It is also said to be diminished in anemia; but the 

 pallor which characterizes that disease is due to a deficiency 

 in the number of the red blood-corpuscles, as well as to the 

 altered constituents of the same. The temperature 

 of the body is increased in diseases accompanied with an 

 increased circulation, as in severe inflammatory fevers. 

 On the other hand, it is lowered in languid states of the 

 circulation, as in apnea, and in poisoning by some drugs. 



THE VASCULAR SYSTEM OF THE FETUS 



The arterial blood destined for the nutrition of the 

 fetus is carried from the placenta to the fetus, along the 

 umbilical cord, by the umbilical vein. The umbilical 

 vein enters the abdomen at the umbilicus, and passes up- 

 ward along the free margin of the suspensory ligament of 

 the liver to the under surface of this organ, where it gives 

 off two or three branches to the left lobe ; one of these is of 

 large size; other branches are given off to the several 

 other lobes of the liver. At the transverse fissure of the 



