[Ultrastructure of various ganglia of autonomic nervous system of the human embryo at the beginning of the mediator stage of ontogeny].

Neural ganglia of the heart and stomach, paravertebral and spinal ganglia have been studied electron microscopically in 8-10-week-old human embryos. Amateur neurons in the ganglia are at various stages of differentiation and sometimes they are not divided with glia. In the cardiac ganglia the most mature neural elements are defined, comparing to other ganglia studied. It is demonstrated both in the developmental degree of cellular organelles, including those of the granular endoplasmic reticulum, and in manifestation of the glial tunic. Synaptic contacts at the stage of their formation are revealed in the intracardiac and sympathetic (paraventral) neural ganglia.