384 GLOSSARY 



Non-me-dulla-ted : without the medullary sheath, as nonmedullated 



nerves. 

 Nu-cle-o'lus (Lat., diminutive of nucleus, a little nut) : the nucleus of 



a nucleus. 

 Nu'cle-us (Lat., a little nut) : a central modified mass of protoplasm 



found in nearly all cells. 

 Nu-tri'tion (Lat. nutrire, to nourish) : a term which, in its broad sense, 



includes all the processes concerned in the growth, maintenance, 



and repair of the living body and all its parts. 



Oc-cip'i-tal (Lat. occiput, the back of the head) : pertaining to the 

 hinder part of the head, as the occipital lobe of the brain. 



Oc-u-lo-mo'tor (Lat. oculus, the eye) : pertaining to the movements of 

 the eye ; applied especially to the third pair of cranial nerves. 



0-don'toid process (Gr. odontoeides, tooth-shaped) : the tooth or peg of 

 the axis or second cervical vertebra. 



01-fac'to-ry cells (Lat. olfnctu*, from olere, to have a smell, andfacere, 

 to make) : the cells which are affected by odors ; the end organs 

 for smell, in the lining membrane of the nasal passages. 



Olfactory nerves : the nerves of smell, distributed from the olfactory 

 bulb over the membrane lining the nagal passages. 



Olfactory tract : the band of nervous matter lying between the olfac- 

 tory bulbs (from which the olfactory nerves spread out) and the 

 roots of those nerves in the cerebrum. 



O-men'tum (Lat.) : a fold of the peritoneum. 



O'pi-um (Gr. opion, poppy juice) : the juice of the poppy, thick- 

 ened into a sticky brown mass of bitter taste and peculiar odor. 

 It is a stimulant narcotic, and powerfully affects the central nerv- 

 ous system. 



Op'tic (Gr. optikos) : pertaining to sight. 



Optic chi-as'ma (Gr., two lines crossed) : the crossing of the optic 

 nerves. 



Optic com'mis-sure (Lat. con, with, and mittere, missus, to place) : the 

 union of the optic nerve fibers from the two eyes, after passing 

 through the openings in the eye sockets. 



Optic thal'a-mus (Lat., chamber) : masses of gray matter at the base 

 of the cerebrum. 



OrT)it (Lat. orbis, circle) : eye socket. 



Or'gan ((Jr. organon, an instrument) : one of the parts or members 

 of a body which has some specific function ; as the organ of vision. 



