Combined baroreflexes upon resistive, capacitive vessels and external respiration. A concept of cardio-vascular-respiratory system

The investigation was intended to study the role of baroreceptors of hemodynamically isolated zone of vertebral arteries in regulation of peripheral veins tonus, arterial pressure and external respiration. Pressure decrease in this vascular reflexogenic zone led to reflex responses of increase in femoral vein tonus, elevation of blood pressure level and stimulation of external respiration. The opposite reflex reactions of cardio-respiratory functional system to initial pressure activation of vertebral arteries baroreceptors are observed. Basing on generalization of our own findings and similar researches of other authors, it is established that afferentationfrom the vertebral arteries zone is a reflexogenic factor of somatic muscles’ veins tonus regulation. These reflexes of capacity vessels tonic activity changes are part of cardio-respiratory responses of maintaining the tissue gaseous exchange. Aconsept of cardio-vascular-respiratory functional system are introduced.