Abstract
After isolating the tectorial membrane of whole coil or each turn, measurements of them were carried out. The best way of measurements was found to observe in saline solution after fixing by neutral 10% formalin.
The results obtained were as follows:
1) Total length of the tectorial membrane was 18mm.
2) The most widest total width including limbus and tectorial part was second turn. It was 244±9.2μ.
3) The width of the tectorial part was 45±5.5μ at hook end, 114±7.5μ at basal turn, 128±4.6μ at second turn, 134±5.4μ at third turn and 135±5.5μ at apex respectively. The width of the tectorial part increased from hook to basal turn abruptly, after which it increased gradually. The tectorial width of the apex showed 3 times as wide as hook end.
4) It was observed by differential interference microscope that the thickness of the tectoiral membrane-increased from apex to base gradually. The difference of each coil of the tectorial membrane was also observed.
5) The shrinking of the tectorial membrane after alcian blue staining implied that the observation of the tectorial membrane in physical condition was impossible by ordinary histochemical technique.
6) The change of the width of the tectorial membrane in proportion to that of basilar membrane implied that the tectorial membrane participated physically in hearing mechanism.
