Physiology : a manual for students and practitioners . External View of a fast of the LeftLabj-riuth (Heiile): /, fenestracochleie, or round window; a,fenestra vestibuli, or oval win-dow ; 6, ampulla of superior semi-circular canal; d, common shaftof union of these two canals; e,ampulla of the horizontal semi-circular canal; g, tractus spiralisforaniinosus. These canals are arranged 158 THE SENSES. resemblance to a snail-shell. It is divided into two parts, by bonyand membranous structures, which run parallel from base to apexof the spiral (Fig. 45). The upper passage opens into the vesti- FiG
Physiology : a manual for students and practitioners . External View of a fast of the LeftLabj-riuth (Heiile): /, fenestracochleie, or round window; a,fenestra vestibuli, or oval win-dow ; 6, ampulla of superior semi-circular canal; d, common shaftof union of these two canals; e,ampulla of the horizontal semi-circular canal; g, tractus spiralisforaniinosus. These canals are arranged 158 THE SENSES. resemblance to a snail-shell. It is divided into two parts, by bonyand membranous structures, which run parallel from base to apexof the spiral (Fig. 45). The upper passage opens into the vesti- FiG. Bony Cochlea of the Human Ear, right side, opened from its anterior face (Cruveilhier). bule, and is known as the scala vestibuli; the lower, the scalatympani, is shut oif by a membranous partition, which covers theforamen rotundum. from the cavity of the tympanum. The scalavestibuli is subdivided by a fibrous membrane (of Reissner) whichpasses from the bony lamina spiralis to the wall of the scala ves-tibuli, shutting off a triangular space (canalis cochlearis). Thefloor of this space is the membranous partition (membrana basi-laris) which separates the scala tympani from it, and upon thismembrane is the organ of Corti. What is the function of the cochlea ? It is to spread out, over as large a surface as may be, the mech-anism for the reception of sounds by the organ of Corti, the end-organ of the auditory nerve. It seems to be especially well adaptedfor this purpose, because the solid spiral lamina connects it with thebony framework of the skull, while it is contained in the mem-bra
Size: 1841px × 1358px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, booksubjectphysiology, bookyear1
