. Surgery, its principles and practice . ss. The upper portion of the drum membrane, or membrana flaccida or Shrapnells membrane, fills in the space between the anterior and posterior spines of the auditory process or tympanic ring. Its upper attachment is really the squamous plate of the temporal bone, just behind the posterior root of the zygoma, and it is really a portion of the periosteum of this part of the temporal bone. This division of the drum membrane into two portions, an upper portion or flaccid membrane, or membrana flaccida, and a lower portion or tense membrane, or membrana tens
. Surgery, its principles and practice . ss. The upper portion of the drum membrane, or membrana flaccida or Shrapnells membrane, fills in the space between the anterior and posterior spines of the auditory process or tympanic ring. Its upper attachment is really the squamous plate of the temporal bone, just behind the posterior root of the zygoma, and it is really a portion of the periosteum of this part of the temporal bone. This division of the drum membrane into two portions, an upper portion or flaccid membrane, or membrana flaccida, and a lower portion or tense membrane, or membrana tensa, is of the utmost importance clinically. Within the tympanic cavity is the ossicular chain, composed of themalleus, incus, and stapes. The malleus is attached by its manubriumto the drum membrane, and the manubrium mallei passes downwardand backward through the membrane to a point just below the center ofthe membrana tensa. The upper extremity of the manubrium malleiis marked by a prominence, known as the short process of the malleus,. ANATOMY OF THE EAR. 799 and a horizontal line drawn through this short process marks the separ-ation between the membrana tensa below and the membrana flaccidaabove. The short process presents as a prominent bony point, pushingthe drum membrane outward at a point about 1 or 2 mm. below thesuperior wall of the external auditory canal. As the ligaments whichhold the malleus in position, and about which it rotates, all pass throughthe short process, the position of this process is fixed and immovable,no matter what changes may take place within the tympanic importance as a landmark, therefore, cannot be overestimated. Theentire manubrium mallei thus lies below the short process. The neckof the malleus lies opposite the membrana flaccida, while the head of themalleus and the body of the incus are completely inclosed in a spaceabove the superior canal wall, and are entirely surrounded by bonywalls. This cavity is known as the tympanic vau
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