448 GLOSSARY 



Nu'cle-us (Lat. nucleus, kernel), a mass usually distinguishable near the 

 center of each cell. It seems to be endowed with special vital powers. 



Oc-cip'i-tal region (Lat. 06, against, and caput, the head), the region 

 of the skull or brain which is situated farthest back. 



0-le-o-mar'ga-rine, a compound made from beef fat and milk. It has 

 the properties and nutritive value of butter. 



01-fac'to-ry (Lat. olere, to have a smell, and facer e, to make), pertain- 

 ing to the sense of smell. 



0-men'tum (Lat. omentuni), the fatty apron in front of the intes- 

 tine. 



O'pi-um (Gr. opion, poppy juice), the dried juice of a kind of poppy 

 growing in western Asia. It is a narcotic and is used to produce 

 sleep and to benumb pain. 



Op'tic (Gr. optikos), pertaining to sight. The optic nerves convey 

 impressions of sight. The optic tubercles are collections of gray 

 matter in the brain between the medulla and cerebrum. They are 

 reflex centers for the eye. 



Or'bit (Lat. orbis, a circle), the bony cavity which contains the 

 eyeball. 



Or'gan (Gr. organon, a tool), a collection of tissues having a definite 

 compact form and purpose. 



Or-gan'ic (Gr. organon, a tool), a term designating a substance built 

 up only by the agency of living substances. 



Ox-i-da'tion, the union of oxygen with another substance. It is the 

 essential part of the processes of burning and of breathing. 



Oxygen (px'y-jen) (Gr. oxus, sharp or acid, and genein, to generate), a 

 gas forming one fifth of the air. Its union with the cells of the 

 body forms the essential part of the process of breathing. 



O'zone (Gr. ozon, smelling), a very active form of oxygen formed by 

 electricity and sometimes found in the air. 



Pal'ate (Lat. palatum), the roof of the mouth. 



Pal-pi-ta'tion (Lat. palpitare, to throb), violent throbbing of the 



heart, so that its beats make themselves felt through the chest wall. 

 Pan'cre-as (Gr. pan, all, and kreas, flesh), the gland situated behind 



the stomach which forms the pancreatic juice. The sweetbread. 

 Pan-cre-at'ic juice, the liquid secretion of the pancreas which digests 



albumin, fat, and sugar in the intestine. 



