GLOSSARY I8l 



R. 



Ra'di-us, the bone upon the thumb side of the arm, extending from the 



elbow to the wrist. 

 Re'flex ac'tion, the act of the spinal cord in sending orders for action 



in response to information from the cells. It provides for the wants 



and for the protection of the cells. 



S. 



Sa-li'va, the fluid always found in the mouth. It moistens the mouth, 



softens food, and turns starch to sugar. 



Scap'u-la, the flat bone behind the shoulder; the shoulder blade. 

 Sen'ses, the five means by which the mind gets knowledge of the world 



outside of the body. They are seeing, hearing, feeling, smelling, 



and tasting. 

 Sen'so-ry nerve, a nerve which carries impressions from the cells to 



the spinal cord or to the brain. 



Sew'er, an underground tunnel which carries away slops from houses. 

 Skel'e-ton, the bones of the body. 

 Skull, the bony structure of the head. 

 Spi'nal cord, the nervous cord inside the backbone. It gives off 



nerves, sends reflex orders to the cells, and conducts impulses to 



and from the brain. 

 Starch, a food substance found in nearly all kinds of vegetable food. 



Corn starch and common laundry starch a*re two kinds. 

 Stim'u-lant, from a Latin word meaning a whip ; a substance which, 



like a whip, compels the cells to act, but does not furnish them with 



the power to act. 



Stom'ach, the muscular bag into which food enters when it is swal- 

 lowed. 

 Su'gar, a sweet vegetable food substance. There are many different 



forms, but during digestion all become changed to the kind of sugar 



found in the grape. 



Sweat, the fluid produced by the skin ; the perspiration. 

 Sym-pa-thet'ic sys'tem, the collection of nerve cells and nerves which 



send orders to the muscles of the arteries, stomach, intestine, and 



heart. 

 Syn'o'vi-a, a fluid like the white of an egg, which is found inside of 



joints. 



