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The Cause Of Seasickness

The Cause Of Seasickness image
Parent Issue
Day
29
Month
November
Year
1893
Copyright
Public Domain
OCR Text

Sea arts in th iys a writer in "■■ I:l its eavity are 1 hrei ■ ach bent in a circle, three sit at right angles to each o like the three sides at the corner of :v routn or a box. Consequently, i:i whatever direction the head is moved, the fluid in Bome one of the tubes is given a circular motion. Ilanging out into tho tubes, from their sides, are haira or cilia, wliich connect with nerve cells and fibers tbat branch olï from the auditory nervc. VVhen the head moves the üuid moves, the hairs move, the cells are "fired off," a nervoua eurrent is sent np to the brain and a feeling of the head'a peculiar motion is consequent. As for seasicknese: 'l'his nerve current, on its way to the brain, at one point runs beside the spot or "center" where the nerve governing the stomach has its origin. VVhen the rocking of the head is abnormally ! lent and prolonged, the stimulus is so great that the current leads over into this adjoining "center" and so excites the nerve running to the stomach ;h to cause wretchedness and retching. Deai mutes, whose ear "canals" are affected, are never seasick. Hut nonnally the araount of ear-feeling which we get by reason of moving our head in a particular direction comes in a curious way to be a mensure of the direction of sound. The feelings we get from our skin and muscles iu turnlng the head play a similar role. We turn our ear to eatch a sound. We do this so frequently for every point that in time we learn to judge the direction of the sound by the way we would have to turn tho head in order to hear the sound best. Thereafter we do not have to turn the head to get the direction, for we now remembcr the proper feeling and know it. This memory of the old feeling is our idea of the present direction. If we never moved our heads we never could have any such notion of the location of sounds as at present - perhaps none whatever.

Article

Subjects
Old News
Ann Arbor Courier