CALIFORNIA COLLE6I 



~ f PHARMACY 



REGULATION OF THE FLOW OF BLOOD IQI 



8. Large blood tubes run down the middle of the limb 



upon the side toward which the limbs are bent. 



9. Tight bands obstruct the flow of blood going from a 



limb, but permit blood to enter. Thus the limb 

 swells and the veins enlarge. 



DEMONSTRATIONS 



78. The effect of injury upon the arteries can be illustrated by scratch- 

 ing the arm with the point of a pin. In a few seconds a bright red 

 mark appears in its track. 



79. Hold the hand in a basin of hot water. Notice that at first the 

 skin is red from the dilatation of the arteries. In course of ten min- 

 utes the skin becomes white and puckered, because heat has a second 

 effect of contracting arteries. 



80. Show how bleeding can be stopped, by boldly grasping an imag- 

 inary cut and holding its edges tightly together. Show how a band 

 can be tied loosely around a limb above a cut, and then by means of a 

 stick inserted under the band, can be twisted as tightly as one pleases 

 so as to control bleeding. 



REVIEW TOPICS 



1. Describe vaso-motor nerves. 



2. Show how vaso-motor nerves are affected by influences 



from the brain ; by heat and cold ; by injuries. 



3. Describe congestion and how it is caused by cold. 



4. Give the effects of alcohol upon the contraction and 



dilatation of the arteries. 



5. Give the difference between arterial, capillary, and 



venous bleeding. 



6. Describe how bleeding naturally stops. 



7. Describe three ways of stopping bleeding. 



8. Describe how nature restores the circulation after an 



artery is cut in two ; after a vein is cut ; and after 

 capillaries are cut. 



9. Give the effect of tight bands upon the circulation of a 



limb. 



