Three-Dimensional Analysis of Morphological Aspects of the Human Utricular Macula

The 3-dimensional shape of the human utricular macula and its orientation in the skull are quantitated in this report, which is one of a series. The semicircular canals and utricular macula were reconstructed in 3 dimensions on a computer from 3 human temporal bones. The 238 to 279 triangles in the entire area of the utricular macula were made by drawing lines between 2 adjacent points every 200-μm width of the utricular macula in each section. We calculated the angles between each triangle and each estimated standard axis in the skull. This study provides standard data regarding the 3-dimensional morphological aspects of the utricular macula for further investigation of the function of the utriculus. We determined that the 3-dimensional shape of the utricular macula was not a plane, but was a curved surface like that of an ellipsoid. We believe this shape is necessary for the utricular macula to detect wide-range linear acceleration.