EESPIRATORY, OR BREATHING, ORGANS. 401 



the intestines than in other parts. These glands are diseased 

 in farcy, and the enlargement of those near the skin constitutes 

 farcY-buds. These A^essels take up any fluid that may be 

 thrown out by the blood not necessary for repairing the sys- 

 tem, as also the worn-out particles, and absorb from the bowels 

 a part of the digested food passing through them. 



EESPIKATOEY, OE BEEATHING, OEGANS, 



These are the larynx, the windpipe, the bronchial tubes, and 

 the lungs. But I shall describe under this head the pleura,. 

 which is only indirectly concerned in breathing. 



The larpix is situated in the throat at the upper part of the- 

 windpipe, between the back part of the sides of the lower jaw. 

 It is the beginning of the air-passages. It is composed of five 

 pieces of cartilage, bound together by ligaments and mem- 

 branes, forming a cavity of considerable size, which is continued 

 back into the windpipe, and opens forward to admit the air 

 from the back openings of the cavities of the nose. Its for- 

 ward opening is called the glottis, which is a long slit, or open- 

 ing, about six times as long as it is wide. It has two slips of 

 membrane attached to the back part, by which it is drawn tight 

 or left loose. The glottis is covered by the ejnglottis, which is. 

 a cartilage fitting over/it like a lid, and w^hich raises to admit- 

 air, but closes against any thing solid. 



The glottis and the cords spoken of, called vocal cords, art 

 the principal agents in producing the voice. But the whole 

 larynx is somewhat concerned in producing the voice. 



The toindjpipe, or trachea, is a tube of about twenty-five or 

 thirty inches in length. It extends from the larynx back along 

 the lower part of the neck between the tw^o first ribs, and term- 

 inates in two branches, called the bronchial tubes, under the 

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