[Spatial orientation of the structures of the ventral surface of the medulla oblongata to the vessels of the crus and small intestine].

In acute experiments of 22 cats with simultaneous perfusion of the crus and small intestine's vessels, the neurocytes affecting the neurogenic tone of the vessels were found 2 mm caudal of the middle of exposure of the n. n. hypoglossi roots and 6 mm rostral of this level, the depth being 1000-2000-3000 mu ventral of the medulla oblongata surface. Cerebral structures situated at the level of the middle of exposure of the n. n. hypoglossi roots, 2-4-6 mm rostral of this level, at the depth 1000-2000-3000 mu and stimulation of which increases regional vascular resistance, are called pressor ones. Electrical activity of the neurocytes situated 2 mm caudal of the middle of exposure of the n. n. hypoglossi roots, at the depth 1000-2000-3000 mu, mostly decreases neurogenic tone of the organ vessels (depressor area). Proportional dependence of the vasoconstrictor response of the vessels on the stimulation intensity was only found in activation of neurons in the points of pressor area. A greater increase (1.5-fold) of perfusion pressure in the crus vessels as compared with the small intestine's those in stimulation of comparable points of the pressor area suggests different density of distribution of the neurons affecting neurogenic tone of the crus and small intestine's vessels.