First Book in Physiology and Hygiene by John Harvey Kellogg
page 62 of 172 (36%)
page 62 of 172 (36%)
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little white bands are stretched across the inside of the voice-box.
When we speak, these bands vibrate just as do the strings of the piano. These bands are called the _vocal cords_. ~16. The Epiglottis.~--At the top of the voice-box is placed a curious trap-door which can be shut down so as to close the entrance to the air-passages of the lungs. This little door has a name rather hard to remember. It is called the _epiglottis_ (ep-i-glotĀ“-tis). The cover of the voice-box closes whenever we swallow anything. This keeps food or liquids from entering the air passages. If we eat or drink too fast the voice-box will not have time to close its little door and prevent our being choked. Persons have been choked to death by trying to swallow their food too fast. Do you not think this is a very wonderful door that can open and shut just when it should do so without our thinking anything about it? ~17. The Nostrils and the Soft Palate.~--The air finds its way to the lungs through the mouth or through the two openings in the nose called the _nostrils_. From each nostril, three small passages lead backward through the nose. At the back part of the nasal cavity the passages of the two sides of the nose come together in an open space, just behind the soft curtain which hangs down at the back part of the mouth. This curtain is called the _soft palate_. Through the opening behind this curtain the air passes down into the voice-box and then into the lungs. ~18. The Pleura.~--In the chest the air tubes and lung of each side are enclosed in a very thin covering, called the _pleura_. The cavity of the chest in which the lungs are suspended is also lined by the pleura. A limpid fluid exudes from the pleura which keeps it moist, so that when the two surfaces rub together, as the lungs move, they do not become |
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