|
The macula of the utricle, or utricular macula is the region of the utricle that receives the utricular filaments of the vestibulocochlear nerve. The portion of the utricle that forms the macula forms a sort of pouch or cul-de-sac, with a thickened floor and anterior wall. The macula of utricle allows a person to perceive changes in longitudinal acceleration (in horizontal directions only). ==Layers== The macula consists of three layers. The bottom layer is made of sensory hair cells which are embedded in bottom of a gelatinous layer. Each hair cells consists of 40 to 70 steriocilia and a kinocilium, which lies in the middle of the steriocilia and is the most important receptor. On top of this layer lie calcium carbonate crystals called statoconia or otoliths. The otoliths are relatively heavy, providing weight to the membrane as well as inertia. This allows for a greater sense of gravity and motion. The gelatinous layer and the statoconia together are referred to as the otolithic membrane, where the tips of the stereocilia and kinocilium are embedded. When the head is tilted such that gravity pulls on the statoconia the gelatinous layer is pulled in the same direction also causing the sensory hairs to bend. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Macula of utricle」の詳細全文を読む スポンサード リンク
|