[Micromorphology of the intraorganic nerves of the hand muscles in human fetuses of the 2d half of the prenatal development and in children up to 1 year of age].

The intraorganic nerves of the fetus hand muscles in the second half of the prenatal development (beginning from the 4.5th month of the intrauterine development) have a conductive part in the nerve system with certain signs of immaturity: weak branching of the neural trunks, abundant perineural cells, great amount of the intratrunkal plexuses, various forms of the neural fibre transversal section. By the time of birth, in the fetal neural trunclets fine fibres predominate, percent of the middle one increases. After birth, general architectonics of the intraorganic nerves remain the same. During the first year of life, the amount of the intramuscular nerves and their branchings increases, the neural fibres acquire a more regulated course, the intratruncal plexuses become less pronounced. In the neural faciculi, percent of the middle fibres increases essentially, the thick ones appear. By the first year of life, a considerable difference in the intratruncal structure of the intraorganic nerves in the eminence muscle of the thumb and the little finger becomes evident.