Vegetative nervous system controls activity of all organs concerned with vegetative functions of body (nutrition, respiration, excretion, reproduction) and accomplishes trophic function. Vegetative nerve system is separated into two parts: 1) sympathetic part; 2) parasympathetic part – carries a protective role: constriction of the pupil in bright light; inhibition of cardiac activity.
Interoceptive analyzer: doesn’t possess a compact conducting pathway. Its receptors termed interoreceptors, are scattered in all organs of vegetative life (viscera, vessels, smooth muscles). The conductor – is formed of afferent fibres of vegetative nervous system, running in the cranial nerves, and carrying impulses from organs. Finally, the cells of the 3rd link are located in thalamus.
Nerve supply of organs of the abdominal cavity:
Celiac plexus: The abdominal part of the sympathetic trunk sends odd a great number of branches which, together with the greater and lesse splanchnic nerves and the abdominal segments of vagus nerves form largest unpaired coeliac plexus. It occupies the area between renal arteries, suprarenal glands and aortic opening of diaphragm. Coeliac plexus also gives smaller paired plexuses to suprarenals, kidneys as well as the testicular plexus. There is also superior mesenteric plexus which supply pancreas, small intestine, large intestine, half of transverse colon.
Aortic plexus: The second main source of innervation of abdominal organs is the plexus on the aorta – aortic plexus (plexus aorticus abdominalis), formed by two trunks arising from coeliac plexus and branches running from the lumbar ganglia of sympathetic trunk.