V.I. Torshin - Dr.Sc. (Biol.), Professor, Head of Department of Normal Physiology, Department of Normal Physiology, Medical Faculty, Russian Peoples\' Friendship University. E-mail: V.I.Torshin @ mail.ru D.S. Sveshnikov - Dr.Sc. (Med.), Associate Professor, Department of Normal Physiology, Medical Faculty, Russian Peoples\' Friendship University. E-mail: dmsveshnikov@gmail.com I.L. Myasnikov - Ph.D. (Med.), Associate Professor, Department of Normal Physiology, Medical Faculty, Russian Peoples\' Friendship University. E-mail: mil@mail.ru