220 ANATOMY AND PHYSIOLOGY 



of the artery from which the blood comes (as a tourniquet applied 

 above the wound), by compress and bandage over the wound. 2. 

 To cause contraction of the vessels: by applying heat hot water 

 118 to 1 20 in a rapid stream if available, otherwise in hot com- 

 presses, or cold ice is best; by the use of adrenalin, and possibly 

 by styptic solutions which cause a coagulum by chemical action. 

 (Among domestic remedies, vinegar has a reputation.) 



For internal hemorrhage, if of the head or upper part of the body 

 elevate head and shoulders moderately, command rest. If in 

 the pelvis or lower part of the body, elevate the foot of the bed, 

 protect from excitement, secure rest. If from the lungs, elevate 

 shoulders, forbid speaking. 



In case of sudden and profuse bleeding, when the vessels are 

 rapidly emptying themselves, bandage limbs to secure tension 

 by driving the blood into a smaller area, and to lessen the demand 

 upon the heart; prepare for hypodermoclysis, saline transfusion 

 or blood transfusion. 



Since capillary blood does not coagulate direct pressure and 

 time are required for the control of capillary hemorrhage. 



Opsonins and the opsonic index. It is believed that the phago- 

 cytic action of white cells is regulated by the presence in the blood 

 of chemical substances (still undescribed) called opsonins, by 

 which invading bacteria are prepared for absorption and digestion 

 by the phagocytes. The measure of the power thus residing in the 

 blood is expressed as the opsonic index. The opsonic index is high 

 or low, according to the number of bacteria which the opsonins 

 may assist the cells to dispose of. 



There is some reason for thinking that a special opsonin exists 

 for each kind of bacterium. 



In addition to opsonins the blood contains enzymes, also 

 various antibodies and immune bodies, which either protect the 

 body from specific infections, or assist in overcoming invasions 

 which have already occurred (see p. 214). Each separate poison 

 or bacterium has its own antibody. The so-called internal 

 secretions are also carried by the blood (p. 263). 



