Fine structure of developed human tongue muscle.

The purpose of this study was to clarify the relationship myofibrils, mitochondoria and other cytoplasmic organella in the developed lingual muscle (vertical, transverse, and longitudinal) by using various microscopic levels: light, scanning electron, and transmission electron. The tongue muscles were examined in seventeen autopsy specimens: eight, 12-32 weeks gestation and ten adults (five male, five female; 54-93 years). The muscle fiber rapidly developed. A large number of mitochondoria and glycogen granules increased and the size of myofibrils in the middle stage also increased, ranging from 24 to 28 weeks gestations. The developed myofibrils were differentiated, the VL and TL at first are developed before the LL developed. These results suggest that the lingual intrinsic muscle have differences in properties during development.