title: [Maximal modes of blood circulation].
abstract: In 44 sportsmen under maximal physical loads, the maximal O2 transport was effectively maintained by different modes of the circulation. The optimal mode is: Q = 2.9 + 5.43 VO2 + 0.61 V2O2 - 0.099 V3O2 (where Q is the minute blood volume; VO2--oxygen consumption). This mode involves proportional contributions of the central and the peripheral mechanisms of the organism O2 supply. The expressive mode involves increased O consumption and minute blood volume (on the average 37.72 +/- 3.0 l/min), and a relatively small arterial-venous difference (on the average 141.5 +/- 13.1 ml/l). The reduced mode of circulation involves relatively small values of the minute blood volume (on the average 29.76 +/- 1.64 l/min) and an obvious increase of the arterial-venous difference in oxygen (on the average 180.9 +/- 14.3 ml/l). Formation of one or another hemodynamic mode is related to an individual blood volume velocity. In particularly high values of the minute blood volume, the O2 transfer from capillaries is limited by the flow. A relative decrease of the minute blood volume increases the contacting time of the blood with muscle tissues aiding to excessive extraction of O2 and thereby increasing the arterial-venous difference.
mesh_terms: D000293:Adolescent; D000328:Adult; D001775:Blood Circulation / Q000187:drug effects; D001810:Blood Volume / Q000187:drug effects; D002245:Carbon Dioxide / Q000502:physiology; D004562:Electrocardiography; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000187:drug effects; D005082:Physical Exertion; D011433:Propranolol / Q000494:pharmacology
chemical_list: D002245:Carbon Dioxide; D011433:Propranolol
vernacular_title: Maksimal'nye rezhimy krovoobrashcheniia.