[Information of the structuro-functional characteristics of sympathetic afferents]

Visceral nerves have a lot of sensitive conductors of double nature. One of them are presented by dendrites of pseudounipolar cells of cerebrospinal nodes, others - in the form of amyelinic (or, sometimes, fine myelinic) fibres - are axons of peripheral sensitive neurons (of the IId Dogil's type). By means of experimental morphological and electrod physiological analyses performed in 36 dogs, a possible connection of intraenteric neurons of the IId Dogiel's type with the spinal cord is demonstrated, at least with in the level of 5-10 thoracic segments. The centripetal fibres from the jejunum go together with the intestinal, coeliac nerves, intranodular, white and grey connective branches of the sympathetic trunk and, further - with posterior and anterior roots of the cerebrospinal nerves. The coeliac nerves serve as an important collector of the sympathetic afferents along their way from the peritoneal cavity. A part of axons of the peripheral sensitive neurons end in presynaptic buds of a terminal type on the motoneurons in the prevertebral (coeliac plexus) and the paravertebral (thoracic sympathetic trunk) sympathetic ganglia accepting the positoin of the afferent link in the systems of extracentral reflex arcs. Owing to this sign, sensitive cells of the IId Dogiel's type are justly named "sympathetic afferent neurons". Elements of the peripheral (sympathetic) afferent system are remarkable for their diffuse localization, that is corroborated by: an extreme dispersity of trophic centers (cells of the IId Dogiel' type); their axons form synapses with motor cells of numerous and sometimes unstable, individually changeable sympathetic ganglia; transfer of the centripetal sensitive fibres into the spinal cord via posterior and anterior roots.