NEPHROZYMOSE 



Nephrozymose {nef-ro-zi' -moz) [yeopog , kidney ; £r/*//, 

 leaven]. A gum resembling diastase sometimes found 

 in urine. 

 Neptune's Cingulum or Girdle. Cingulum neptuni, 

 a folded sheet, the end of which has been soaked in 

 hot water, wrung out and applied to the abdomen, the 

 larger and dry portion being utilized as a bandage. 

 See Girdle. 

 Neptunium (nep-tu' '-ne-um) \_Xeptunus, a sea-god]. 

 A doubtful new element obtained from columbite. 

 Atomic weight, 118. 

 Nerac, Pian of. An herpetic form of syphilis. 

 Neritic (ne-ril'-ik) [^Srjpirrjc, son of Nereus]. In 

 biology, a term applied to the swimming faunas and 

 floras [plankton) of the coast regions of the continents 

 well as the archipelagoes and islands. Their com- 

 ition is essentially different from that of the oceanic 

 kton, and they are quantitatively as well as quali- 

 vely richer. 



urn (ne'-re-um) [vijpiov, the oleander]. The 

 ves and root of X. odorum, the common oleander, 

 e extractive principles exert a marked effect on the 

 otor centers, in lethal doses producing paralysis and 

 ath from heart-failure. In small doses they act as a 

 diac tonic resembling digitalis. Dose of the extract 

 . . The tincture may be given cautiously, in 

 e-drop doses, gradually increased. Unof. 

 Neroli, Oil of. See Aurantium. 

 Neronian Phlebotomy. Venesection in which several 



veins are opened simultaneously. 

 Nerval {ner'-val) [wrw«, anerve]. Pertaining to a 



nerve or nerves. 

 Nervate [ner'-zat) \jiervus, a nerve]. In biology, 



having nerves, as a leaf. 

 Nervation (ner-va' -shun) \nervus, a sinew or nerve]. 

 In biology, the arrangement or disposition of the fibro- 

 vascular bundles in the blades of leaves, or of the 

 nerves or veins of an insect's wing; innervation. 

 Nervature (ner* '-vat-iir) . Same as Nervation. 

 Nervaura (ner-vauZ-rah) [nervus, nerve ; aura, air]. 

 A subtle hypothetic essence emanating from the ner- 

 vous system, and enveloping the body in a kind of 

 sphere. 

 Nerve (nerv) [nervus, nerve]. A nerve is an elongated 

 cord or tract of protoplasm made up of aggregations 

 " nerve-fibers and having the property of transmitting 

 pulses. N., Accelerator. Synonym of A'., Aug- 

 entor. N., Afferent, one that transmits impulses 

 m the periphery to the central nervous system. 

 Anabolic, one directly or indirectly bringing 

 ut constructive metabolism. N., Arresting. Same 

 X. Inhibitory. N., Augmentor, the cardiac sym- 

 thetic nerves, stimulation of which causes accelera- 

 n of the heart's action. N.-aura. Same, as Xer- 

 aura. N.-axis, the axis-cylinder. See X. -fiber. 

 .-bristles, fine broaches barbed on one side, or 

 th the end bent at right angles, employed for re- 

 oving devitalized pulps from the canals of the teeth, 

 .-broach, a wire instrument for extracting the nerve 

 a tooth. N., Calorific, a nerve, stimulation of which 

 creases the heat of the parts to which it is distributed. 

 The term is applied to the dilator nerves and to those 

 stimulating functional activity of organs. N. -canal, 

 the pulp-cavity of a tooth. N. -canal Reamer, an 

 instrument for enlarging the pulp-canal of a tooth, 

 prior to the filling of the canal. N. -capping, a cap 

 placed over a tooth to protect an exposed nerve. N., 

 Catabolic. See X. , Katabolic. N.-cell, a mass of 

 protoplasm containing a large vesicular nucleus within 

 which lies a well-marked nucleolus. Nerve-cells have 

 one or more elongated processes, and in accordance 

 with the number of these are designated unipolar, bi- 



845 NERVE 



polar, or multipolar. The processes are of two kinds : 

 the axis-cylinder process and the protoplasmic process. 

 The axis-cylinder (Deiter's) process either becomes 

 continuous with the axis-cylinder of a nerve fiber, or 

 divides within the gray matter into minute branches 

 forming a delicate network. N. -cement, neuroglia. 

 N. -center, a group of ganglion-cells acting together in 

 the performance of some function. N., Centrifugal. 

 Synonym of X., Efferent. N., Centripetal. Syn- 

 onym of X., Afferent. N., Cerebral, a cranial nerve, 

 q.v. N. -chord. Same as X.-cord. N.-cord, anerve ; 

 a cord composed of nervous tissue. N. -corpuscles, 

 nucleated corpuscles lying between the neurilemma 

 and the medullary sheath of medullated nerve-fibers ; 

 they are stained by methyl-anilin. N., Cranial, a 

 nerve arising directly from the brain, the oblongata 

 or the cervical part of the cord, and making its exit 

 through one of the foramina in the skull. N. -current, 

 a current, by some thought to pass through the nerves 

 and muscles. N., Depressor, an afferent nerve, irri- 

 tation of which depresses or inhibits the vaso-motor 

 center. N. -drill, an instrument for enlarging the pulp- 

 cavity of a tooth. N., Efferent, one carrying impulses 

 from the central nervous system to the periphery. N.- 

 eminence. Same as X. -hill. N. -endings, the ter- 

 minations of nerves at the periphery or in the nerve- 

 centers. N. of Expression, the facial nerve. N.- 

 fat. Same zsProtagon. N. -fiber, a fiber having the 

 property of conducting invisible or molecular waves 

 of stimulation from one part of an organism to another, 

 and so establishing physiologic continuity between 

 such parts, without the necessary passage of waves of 

 contraction (Romanes). There are two kinds of 

 nerve-fibers : the medullated and the non-medullated. 

 A typical medullated fiber consists of: (a) the axis- 

 cylinder, which may be surrounded by a sheath, the 

 axilemma ; (b) the medullary sheath, or white sub- 

 stance of Schwann ; (c) the neurilemma , or sheath of 

 Schwann. The axis-cylinder consists of fine fibrillse 

 cemented together by a granular interstitial substance, 

 the neuroplasm. The medullary sheath consists of a 

 reticulated framework composed of a material resem- 

 bling neuro-keratin , and a semifluid substance filling 

 the interstices, called myelin. At regular intervals 

 the medullated sheath is marked by interruptions, the 

 nodes of Ranvier. Each internode, as the portions of 

 fiber included between two Ranvier's nodes are termed, 

 possesses a nerve-corpuscle . Under certain conditions 

 the white substance of Schwann is seen to be com- 

 posed of elongated pieces, the so-called Schmidt- 

 Lantermann segments. These may be artifacts. The 

 neurilemma, sheath of Schwann, or primitive sheath, 

 is a delicate elastic membrane, closely investing the 

 medullary substance. On its inner surface are placed 

 the nerve-corpuscles. The non-medullated, pale, or 

 Remak's fibers, do not possess a medullary sheath, 

 but consist only of axis-cylinder and neurilemma. 

 The nerve-corpuscles are more abundant than in me- 

 dullated nerve-fibers. Medullated nerve-fibers are 

 found in the cerebro-spinal nerves, while non-medul- 

 lated fibers occur in the sympathetic nerves and tend 

 to form plexuses. Nerve-fibers are aggregated into 

 fasciculi; these in turn unite to form nerve-trunks. The 

 nerve-fibers in a fasciculus are held together by the 

 endoneurium; while each fasciculus is surrounded by 

 a sheath termed the perineurium. The epineurium 

 holds together the several fasciculi composing a nerve- 

 trnnk. N. -fiber, Amyelinic. A synonym of non- 

 medullated nerve-fiber. See N. -fiber. N. -fiber, 

 Myelinic. A synonym of medullated nerve-fiber. See 

 N.-fiber. N. -fiber, Organic. A synonym of non- 

 medullated nerve-fiber. See .V. -fiber. N. - fiber, 



