VASCULAR SYSTEM. 135 



Jl. Those concerned in digestion. 



Q. Name those organs or parts which do not pour their 

 blood into this vena portal system. 



t/2. The kidneys, ureters, bladder, genital organs, dia- 

 phragm, and abdominal parietes, do not empty their blood 

 into the vena portarum. 



Q. Do the properties, sympathies, and affections of this 

 abdominal venous system agree with the general venous 

 system ? 



J2. They do. 



Q. What membrane is peculiar to the hepatic portion? 



/?. That which is termed the capsule of Glisson; the 

 use of which is unknown. 



Q. What proof is there that the injection of air into the 

 veins is not fatal by impression made on the heart ? 



ft. Because injection of air into the abdominal system 

 with black blood is not fatal, and yet the air must reach 

 the heart. 



Q. How then does air prove fatal when thrown into 

 the blood-vessels? 



t/2. By its action on the brain. In the case alluded to 

 in the last question, the air becomes so united, diluted, 

 &c. before any of it reaches the brain that its power is lost. 



Q. How does the common lining membrane of this ab- 

 dominal system, differ from that of the general venous 

 system ? 



#. It has no valves; these are unnecessary, because the 

 course of the blood is short. There is no agent of impulse 

 in the middle of this system, as you see in the right side 

 of the heart; the effect of such an agent might occasion a 

 reflux as the action of the right ventricle does. 



Q. Is the course of the blood uniform through the liver? 



