Morphological aspects of the hypothalamic-hypophyseal system

Summary The vascularity of the hypothalamus in rats, cats, and dogs was studied with various injection methods. Particular attention was paid to the capillary architecture of the hypothalamus. The density of the capillary bed in the nuclei of the anterior and medial hypothalamus was studied in male albino rats after filling the cerebral vessels with 5 per cent India ink—gelatin mass. The data obtained were compared with the magnitude-S (projection areas of the capillary meshes of the three-dimensional meshwork) distributions and with the calibres of the capillaries. Distinct inverse correlations were demonstrated between these indices. The objective tests used provided evidence that the peculiar features of the capillary architecture in the various nuclei of the anterior and medial hypothalamus are closely connected with the degree of their vascularity. The rich vascularity of the neurosecretory nuclei is discussed in connection with the peculiarities of their metabolism.The author wishes to express his sincere gratitude to Prof. S. M. Blinkov for valuable advice, to Dr. V. I. Prilutsky for the help received from him in biometric treatment and mathematical analysis of the data obtained, and to Natalia Samushkina and Galina Yankova for their helpful technical assistance.