. Elementary biology, animal and human. Biology. 166 HUMAN BIOLOGY VI. The Eak 249. The external ear. — Attached to each side of the head is an oval, more or less flattened expansion, composed largely of car- tilage and connective tissue. The irregular surface of this outer portion of the ear doubtless helps somewhat, like an ear trumpet, to catch and .converge the sound waves into the funnel-like canal which is about an inch long, and leads to the interior of the head. The Hammer. The Shell Tube ICocKka). The Anvil. A. Eustachian Tube. Fig. 55. — Middle and inner ear, greatly enlarged. In the
. Elementary biology, animal and human. Biology. 166 HUMAN BIOLOGY VI. The Eak 249. The external ear. — Attached to each side of the head is an oval, more or less flattened expansion, composed largely of car- tilage and connective tissue. The irregular surface of this outer portion of the ear doubtless helps somewhat, like an ear trumpet, to catch and .converge the sound waves into the funnel-like canal which is about an inch long, and leads to the interior of the head. The Hammer. The Shell Tube ICocKka). The Anvil. A. Eustachian Tube. Fig. 55. — Middle and inner ear, greatly enlarged. In the lining of this canal are certain wax glands; these secrete a thin fluid which, on thickening, hardens into a yellow paste, the earwax. Across the inner end of this tube of the external ear is stretched a thin membranous partition, known as the eardrum, or tym'pa-num (Latin tympanum = drum (Fig. 55)). It is never safe for one to thrust into the canal of the ear any hard object, because of the danger of puncturing the eardrum. Ordina- rily the canal cleans itself, but if it is necessary to remove bits of wax or dirt, this should be done with a tightly rolled corner of a piece of cloth. It is dangerous, too, to punish a child by boxing the ears,. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Peabody, James Edward, b. 1869; Hunt, Arthur Ellsworth, joint author. New York, The Macmillan company
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbiology, bookyear1912
