[Structure and age-related changes of the microcirculatory routes of human parathyroid glands]

Parathyroid glands (648), obtained from 170 cadavers of men and women of different age (from neonatal to the age of 90 years) were examined. Impregnation methods after V. V. Kupriyanov, Gros-Bilshovsky modified by Campos, and general histological methods were used to study the microcirculation tracts. In neonates these tracts are characterized by homogenous structure, immature "accomodations" for the circulation control; the gland capsule displays regional vascular complexes. Formation of the microcirculation tracts of the parathyroid gland courses up to the first period of mature age; later the volume of the venous link of the microcirculation tracts increases due to an elevated number of the convoluted, lacune-like dilated venules, venulo-venular anastomoses. Convoluted arterioles and arteriolo-arteriolar anastomoses appear in old age, and the number of arteriolo-venular anastomoses becomes greater.