COLUMBIX 



313 



COMA 



Columbin (kol-um'-bitt). An active principle of Ca- 

 luraba. It is a colorless crystalline substance of 

 excessively bitter taste and neutral reaction. 



Columbo {kol-um'-bo). See Calumbo. 



Columella {kol-u-mel' '-ah) [L., a little column]. I. 

 The column-like rod of birds and reptiles, a part of 

 the organ of hearing, corresponding to the stapes of 

 the higher animals. 2. The modiolus or central axis 

 of the cochlea of the human ear. See Cochlea and 

 dolus. C. res dentes ; the cuspid teeth are so 

 called from their shape. 



Column {kol'-um) \columna, a column]. A pillar or 

 column. Applied to sundry column-like organs of the 

 body, and especially to certain parts of the spinal cord. 

 C., Anterior, the layer of white matter in either half 



Columns of Spinal Cord. 

 A. C. Anterior commissure. P. C. Posterior commissure. I.g. s. Intermediate gray substance. 

 P. cor. Posterior cornu. c. c p. Caput cornu posterioris. L. L. L. Lateral limiting layer. 

 A.-L. A T. Antero-lateral ascending tract, which extends along the periphery of the 

 cord. (Gowers.) 



of the spinal cord included between the anterior horn 

 and anterior nerve-roots, and the anterior median fis- 

 sure. It contains the anterior or direct pyramidal 

 tract, a portion of the antero-lateral ascending tract, 

 and a portion of the anterior ground-fibers. C, 

 Antero - lateral Ascending. See C. of Goivers. 

 C. of Burdach, the postero-external column of the 

 cord. C. of Clarke, a column of gray substance oc- 

 cupying the region to the outer and posterior part of 

 the central canal of the spinal cord, at the inner part 

 of the base of the posterior cornu. It is most marked 

 in the dorsal region, and contains fusiform cells, some 

 1 with axis-cylinder processes. It is also called 

 -he posterior vesicular column of the cord. C, Direct 

 Cerebellar, in the spinal cord, is situated outside of the 



ateral pyramidal tract, and ventrad of the Spitzka- 



Ussauer column. It is sensory or afferent. C, Dor- 



io-mesal, a name for the posteromedian column of 



he spinal cord and medulla oblongata. C. of Goll, 



he posteromedian column of the spinal cord. C, 



jowers', in the spinal cord, a bunch of fibers lying 



n front of the direct cerebellar tract and reaching 



-round upon the periphery of the anterior pyTamidal 



ract. It is probably a sensory column containing 



he nerves of pain and temperature. C, Lateral, 

 j he layer of white matter in either half of the spinal 

 ' ord included between the posterior horn and posterior 

 ' lerve-roots, and the anterior horn and anterior nerve- 



roots. It contains the lateral pyramidal tract, the di- 

 rect cerebellar tract, and the greater part of the 

 anterior ground-fibers and antero-lateral ascending 

 tract. C. of Morgagni, vertical folds of the rectal mu- 

 cous membrane seen at the point of union of the latter 

 with the skin of the anus. They diminish, but are not 

 entirely effaced, when the bowel is distended. Between 

 their lower ends little arches are sometimes found 

 stretching from one to the other, forming pockets of 

 skin and mucous membrane. These are the sinuses of 

 Morgagni ; they are more developed in old people. 

 C, Posterior, a collection of white-matter situated 

 in the spinal cord on either side between the posterior 

 horns and posterior nerve-roots, and the posterior 

 median fissure. It is divided into two parts by the 

 imperfect intermediate 

 septum, a narrow " pos- 

 tero-median column," and 

 a wide ' ' postero-external 

 column." C, Postero- 

 external, the outer wider 

 division of the posterior 

 column of the cord ; the 

 column of Burdach. C, 

 Posteromedian, the me- 

 dian division of the poste- 

 rior column of the cord ; 

 the column of Goll. C. 

 of Rolando, an eminence 

 on the lateral border of 

 the medulla oblongata. C. 

 of Spitzka-Lissauer, in 

 the spinal cord a group of 

 nerve-fibers lying just in 

 front and just behind the 

 posterior horns or comua. 

 C, Posterior - vesicu- 

 lar. See Column of 

 Clarke. C. of Tiirck, 

 the anterior or direct 

 pyramidal tract. Col- 

 umns of the External 

 Abdominal Ring, the 

 free borders of the apon- 

 eurosis of the external oblique muscle. 

 Columna (kol-um' -nah) [L.]. A column or pillar. C. 

 bertini, that part of the cortical structure of the kid- 

 neys that separates the sides of any two pyramids, and 

 through which the arteries and nerves enter, and the 

 veins and lymphatics emerge. C. nasi, the antero- 

 posterior septum between the nostrils. C. vertebralis, 

 the spinal column. Columnae carneae, muscular col- 

 umns projecting from the inner surface of the cardiac 

 ventricles. 

 Colytic [ko-liP-ik) [*co2vr«<5c, preventive]. Prevent- 

 ive ; inhibitory ; caused by an obstruction ; antiseptic. 

 Coma {ko'-mah) [kd/iji, the hair of the head]. In bi- 

 ology, any tuft, as the top of a pineapple, the hairs on 

 the end of a seed, etc. 

 Coma (ko'-maK) [naua, deep sleep]. Abnormally deep 

 and prolonged sleep, with the cerebral functions in abey- 

 ance ; it is due to many conditions affecting the cere- 

 brum directly or indirectly. The well-marked form is 

 characterized by stertorous breathing, relaxation of the 

 sphincters, lividity of the face, and loss of parallelism 

 of the optic axes. C, Alcohol, that due to poison- 

 ing by alcohol. C, Apoplectic, that due to apoplexy. 

 C. diaceticum, a form of coma occurring in carcinoma 

 of the stomach and in diabetes. It is due to the pres- 

 ence of diacetic acid in the system. It is also called 

 Diabetic coma. C. Kussmaul's. See Kmsmaul. 

 C, Uremic, that due to uremia C. Vigil, a comatose 



