450 GLOSSARY 



Phos'phor-us (Gr. phos, light, and pherein, to bring), a waxy, yellowish 

 substance which combines with oxygen at ordinary temperatures, 

 giving off heat and a faint light. The light produced by rubbing 

 matches is due to the phosphorus. 



Phys-i-ol'o-gy (Gr. phusis, nature, and logos, discourse), the science 

 which tells of the working of living bodies. 



Pi-a ma-ter (Lat. pia, pious, and mater, mother), the delicate cover- 

 ing of the brain which carries its blood vessels, in distinction from 

 the thick protecting dura mater. 



Plas'ma (Gr. plasma, molded), the liquid part of blood in distinction 

 from the cells which float in it. It is composed chiefly of water, 

 albumin, and minerals. It is food for the cells of the body and it 

 washes away their waste matters. 



Pleura (plew'ra) (Gr. pleura, rib), the lining of the chest and coating 

 of the lung. 



Plex'us (Lat. plectere, to braid), a network of sympathetic nerve cells 

 and fibers. 



Plumb'ing (Lat. plumbum, lead), the pipes which conduct water and 

 sewage in a house. Many ar.e made of lead. 



Pneumonia (new-mo* ni-a) (Gr. pneumon, a lung), a disease in which 

 the air sacs of the lung become filled with coagulated matters from 

 the blood. 



Poi'son (Lat. potto, a drink), a substance which destroys or interferes 

 with the life of the cells, when it is taken into the body. 



Por'tal vein (Lat. porta, a gate), the vein formed by the union of the 

 veins from the digestive organs. This vein divides into the capilla- 

 ries of the liver. Finally three veins conduct the blood to the ascend- 

 ing vena cava. 



Pro'to-plasm (Gr. protos, first, and plasma, form), the albuminous sub- 

 stance which forms the body of every living cell. 



Proximate principles, the elementary substances existing as such in 

 the body. 



Ptomaine (to'mah-iri) (Gr. ptoma, a dead body), a class of poison- 

 ous substances resembling alkaloids and leucomaines, which are 

 found in dead bodies. Their presence makes decayed food 

 dangerous. 



Ptyalin (ti'a-ltn) (Gr. ptuein, to spit), the lifeless ferment in the saliva 

 which changes starch to sugar. 



PuTmo-na-ry (Lat. pulmo, lung), pertaining to the lungs. 



