Cohen Y E, Hernandez H N, Saunders J C
Department of Bioengineering, University of Pennsylvania, Philadelphia 19104.
J Morphol. 1992 Jun;212(3):257-67. doi: 10.1002/jmor.1052120305.
The ontogeny of various middle-ear structures was examined in 11 groups of chicks between 10 days embryonic and adult. Measurements of the tympanic membrane surface area and height, columella length, and that of the columella footplate, annular ligament, and oval window area were obtained using video micrographs and computer digitization techniques. The oval window matures first at 53 days post-hatching, whereas the columella achieves adult size at 74 days. The tympanic membrane surface area is the last middle-ear variable studied to reach adult size (79 days post-hatch). The columella increases its length from 0.63 mm (10 days embryonic) to 2.73 mm in the adult. The tympanic membrane area expands by 280% whereas the columellar footplate area increases by 11x. As a result, the pressure amplification of the middle ear due to the tympanic membrane/columellar footplate area ratio improves by over 400%. These data further contribute to our understanding of the functional development of the middle ear.
在11组胚胎期10天至成年期的雏鸡中，研究了各种中耳结构的个体发生过程。使用视频显微照片和计算机数字化技术，测量了鼓膜表面积和高度、听骨长度、听骨足板长度、环状韧带以及卵圆窗面积。卵圆窗在孵化后53天首先成熟，而听骨在74天达到成年大小。鼓膜表面积是最后一个达到成年大小的中耳变量（孵化后79天）。听骨长度从胚胎期10天的0.63毫米增加到成年期的2.73毫米。鼓膜面积扩大了280%，而听骨足板面积增加了11倍。因此，由于鼓膜/听骨足板面积比，中耳的压力放大提高了400%以上。这些数据进一步有助于我们理解中耳的功能发育。
