A complete handbook for the sanitary troops of the U S army and navy . of the spinal cordand ganglia. The special soiscs are , smell, hearing, and three latter are presided overby special cranial nerves, that is,nerves coming directly from thebrain without passing through thespinal cord. The sense of toncli is resident inthe skin generally, but is mosthighly developed in the ends of thefingers. The sense of taste is located in the mouth, more especially in thetongue; for its action it is necessary that the substance should bein solution; this is in accordance with our kn
A complete handbook for the sanitary troops of the U S army and navy . of the spinal cordand ganglia. The special soiscs are , smell, hearing, and three latter are presided overby special cranial nerves, that is,nerves coming directly from thebrain without passing through thespinal cord. The sense of toncli is resident inthe skin generally, but is mosthighly developed in the ends of thefingers. The sense of taste is located in the mouth, more especially in thetongue; for its action it is necessary that the substance should bein solution; this is in accordance with our knowledge that insolublemedicines are tasteless. The sense ofsmell resides in theupper cavi-ties where the fila-ments of the olfac-tory nerve are dis-tributed to themucous membrane(Fig 24). Hearing or theperception of sound vibrations isprovided for bythe ear throughthe auditory ear (Fig. 2O , , ,. Fig. Jj.— .^ of the Ear. B, External ear; .... auilitory canal;consists of the ex- 7, tympanum;/, middle ear;//, ossicles;/-. Eustachian THE NERVOUS SYSTEM AND SPECIAL SENSES 59 tcnial ear, the auditory canal, the tympanum or drum membrane,the middle ear, stretchinj, across which are the small bones orossicles, and the internal ear. The tym])anum is stretched likea drum-head across the auditory canal, separating the external andmiddle ears; in order that the air pressure on the two sides of thedrum may he equalized tiiere is an air tube leading from the middleear to the throat and known as the Eustachian tube; stoppage of thistube in chronic inflammation of the throat is one of the causes ofdeafness.
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfirstaidinillnessand
