[The age-related characteristics of the muscular layer of the common bile duct in man].

Walls of 22 common bile ducts of corpses of both sexes people aged from 21 to 73 were studied. Longitudinal and cross sections of the common bile ducts walls obtained by the improved histotopographical method were stained with hematoxylin-eosin after Jenner-Giemsa, picrofuchsine after Van-Gieson and orsein impregnated after Gordon-Svit and Kuprianov in modification corresponding with biliary tracts tissues. Specific volumes of myocyte bands and connective tissue forming the demonstrated smooth myocytes bands were determined and their correlation was defined in 4 age groups with research material divided in correspondence with the age classification adopted. Changes of capillary-tissue coefficient in ontogenesis were also determined. It was demonstrated that in proximal middle regions the common bile duct muscular coat was represented with longitudinal smooth myocyte bands, isolated from the surrounding loose connective tissue by reticulo-elastic framework. Regular order of these bands forms the crimpet construction of the common bile ducts in longitudinal direction of the tube. By the end of the 2nd maturity period and in elderly age separate location of the myocytes and zigzag course of the bands, their fragmentation with connective tissue layers were observed. Substitution of smooth myocytes with connective tissue fibres occurs. Analysis of the numeral values of the specific volumes obtained mathematically confirms all the morphological transformations listed above. Capillary-tissue coefficient increases in elderly and senile and age indicates disturbance in the tissue metabolism resulting from significant worsening of blood supply.