Jørgensen J M, Christensen J T
Institute of Zoology and Zoophysiology, University of Aarhus, Denmark.
Brain Behav Evol. 1989;34(5):273-80. doi: 10.1159/000116512.
The morphology of the inner ear in rheas was examined by light and electron microscopy. The shape is typically bird-like with very long semicircular canals. The anterior and posterior cristae have small septa cruciata. The vestibular sensory epithelia contain two main types of hair cell innervation; bouton-innervated hair cells and calyceal hair cells characterized by a surrounding nerve calyx. The utricular macula has a single zone of calyceal hair cells, while all other previously examined birds, except the mute swan, have 2 zones. The height of the tallest sensory hairs of the cristae is 20-30 microns. In the utricular and lagenar macula, the hairs are 5-7 microns in the striola and 10-20 microns in the main parts of the sense organs. Along the edges of the maculae the longest hairs may reach 20-30 microns. The number of stereovilli on mature vestibular hair cells is 40-60. The sensory hairs of the hearing organ, the basilar papilla, are generally shorter but more numerous than the vestibular sensory hairs. In the proximal end, the tallest of the 175-200 stereovilli are 2.8-3.7 microns; in the distal end of the papilla, the number of stereovilli decrease to 65-100, and their height increases gradually to 7.3-8.7 microns. The neural sensory hairs are generally taller than those of the abneural side.
通过光学显微镜和电子显微镜检查了美洲鸵内耳的形态。其形状典型呈鸟类特征，半规管很长。前嵴和后嵴有小的交叉隔。前庭感觉上皮包含两种主要类型的毛细胞神经支配；扣结神经支配的毛细胞和以周围神经萼为特征的杯状毛细胞。椭圆囊斑有单个杯状毛细胞区，而除疣鼻天鹅外，所有其他先前检查过的鸟类都有2个区。嵴上最高感觉毛的高度为20 - 30微米。在椭圆囊和瓶状囊斑中，条纹区的毛为5 - 7微米，感觉器官主要部分的毛为10 - 20微米。沿着囊斑边缘，最长的毛可达20 - 30微米。成熟前庭毛细胞上静纤毛的数量为40 - 60根。听觉器官基底乳头的感觉毛通常比前庭感觉毛短，但数量更多。在近端，175 - 200根静纤毛中最高的为2.8 - 3.7微米；在乳头远端，静纤毛数量减少到65 - 100根，其高度逐渐增加到7.3 - 8.7微米。神经感觉毛通常比非神经侧的毛高。
