[Structure of the wall of thoracic lymphatic duct of dogs in postnatal ontogeny]

Light and electronmicroscopic studies have been made on the structure of the wall of the thoracic lymph duct in puppies within 3 months of their postnatal life. It was shown that differentiation and specialization of the smooth muscle cells is accomplished in the main features to the 3rd month of postnatal life. Within this period, the number of the nervous fibers increases, and their linking to the media becomes more close. Absence of dense neuro-muscular contacts indicates distant pattern of the effect of neuromediators on the effector cells. The data obtained demonstrate that during postnatal ontogenesis of dogs changes take place in the barrier properties of the wall of the lymph duct, as well as the formation of morphological substrate for active contractile activity.