Seasonal changes in the circulatory system organs of students in a northern university

The authors have conducted a survey to study seasonal changes in cardiovascular system of the students, who were born and permanently reside in Khanty-Mansi Autonomous Okrug-Yugra. The parameters were recorded in the Laboratory of Human Ecology and Physiology, Nizhnevartovsk State University. 160 students from the faculty of Ecology and Engineering (90 girls and 70 boys aged between 18 and 21) were examined. The indicators of the circulatory system were registered four times a year, i.e. in winter (February), in spring (April), in summer (June) and in autumn (October). The hemodynamics indices and adaptive capabilities of the circulatory system were determined. In the cold months, the cardiovascular system of students from this northern university was in the state of functional stress. Systolic blood pressure, pulse pressure and one-minute blood volume increased. An increase in Robinson index indicates a growing tension in the regulatory system. An increase in the resting heart rate in mid-season suggests less efficient work of heart muscle and exhaustion of the chronotropic reserve. In autumn, students had an increase in sympatic activity, which is proved by positive Kerdo index.