The attachment structure of the guinea pig tympanic membrane

The attachment structure between the tympanic membrane and the surrounding structures, the annular ring and the manubrial part, has not been described fully. We examined the relationship between the tympanic membrane and the tympanic annulus or the handle of the malleus in guinea pigs using light microscopy as well as transmission and scanning electron microscopy (SEM).

We used the temporal bone of the guinea pig and examined the relationship between the tympanic membrane and the surrounding structures using light microscopy and transmission electron microscopy. In the examination of scanning electron microscopy, we used the special method such as alkali-water maceration/SEM method.

The results showed that the radial fibers of the tympanic membrane continued directly into the annular ring and the manubrial part. The histological structure of the annular ring was amorphous and collagen fibers were seen in the amorphous matrix. The manubrial part histologically resembled the annular ring. These structures were associated with the cartilage structure. Our observations indicated that the collagen fibers of the tympanic membrane are a special type of cartilage collagen fibers.

In conclusion, we propose that the surrounding structures of the tympanic membrane such as the tympanic annulus and manubrial part play an important role in the maintenance and the vibration of the tympanic membrane.