Surgical anatomy : a treatise on human anatomy in its application to the practice of medicine and surgery . m its posterior and upper portion forward anddownward, is ten millimeters in length ; the vertical measurement is slightly less ;it is one-tenth of a millimeter in thickness. The membrane is situated obliquely,its outer surface being directed outward, downward, and forward. It is directeddownward and outward at an angle of about forty-five degrees, and forward andoutward at an angle of about ten degrees. In the infant, at birth, this obliquitj isgreater and the membrane is almost horizon
Surgical anatomy : a treatise on human anatomy in its application to the practice of medicine and surgery . m its posterior and upper portion forward anddownward, is ten millimeters in length ; the vertical measurement is slightly less ;it is one-tenth of a millimeter in thickness. The membrane is situated obliquely,its outer surface being directed outward, downward, and forward. It is directeddownward and outward at an angle of about forty-five degrees, and forward andoutward at an angle of about ten degrees. In the infant, at birth, this obliquitj isgreater and the membrane is almost horizontal. Its outer surface is concave, thecenter being the deepest point of the concavity, for the extremity of the handleof the malleus is here attached, and, as it were, draws the membrane de^^ressed center is known as the umbo. The bony ring to Avhich thetjjmpanic membrane is attached is incomplete above, leaving a notch {notch of PLATE CCLIV, Short process of malleus Handle of malleus Anterior fold of membrana tympan Shraphells membrane Posterior fold of membrana tympaniLong process of incus. Umbo Cone of lightAnterior portion of membrana tympani Posterior portion of membranatympani EXTERNAL VIEW OF MEMBRANA TYMPANI OF LEFT EAR,418 THE ORGAN OF HEARING. 419 Rivini), which is filled in by a thinner and looser portion of the membrane,known as the membrana flaccida, or ShrajmeUs membrane. The membranatympani consists of three layers : an outer cuticular covering; a middle, fibrouslayer; and an inner, mucous lining. Inspection.—When viewed through a speculum during life, the membranatympani is of a pearly gray color, and appears smooth and polished. Extendingdownward and backward with its apex at the umbo is a cone of light, which is ofvalue in the diagnosis of disease of the tympanum and membrana handle of the malleus and its short process, and, posterior to the handle ofthe malleus, the long process of the incus, can frequently be seen through themembrane
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectanatomy, bookyear1901
