AUTONOMIC REGULATION OF CARDIOVASCULAR FUNCTION: PHYSIOLOGICAL MECHANISMS OF HEART RATE AND VASCULAR TONE CONTROL

The cardiovascular system plays a fundamental role in maintaining homeostasis by ensuring continuous delivery of oxygen and nutrients to tissues and removing metabolic waste products. Cardiovascular activity is regulated through complex interactions between the autonomic nervous system, cardiac pacemaker mechanisms, vascular smooth muscle, and neurohumoral factors. The sympathetic and parasympathetic divisions of the autonomic nervous system exert opposing and complementary effects on heart rate, myocardial contractility, cardiac output, and vascular tone. Baroreceptor-mediated regulation represents one of the major short-term mechanisms responsible for maintaining arterial blood pressure. Understanding these physiological mechanisms is essential for evaluating cardiovascular adaptation to physical activity, emotional stress, and changes in body position. This thesis summarizes the principal mechanisms underlying autonomic cardiovascular regulation and emphasizes the physiological relationship between heart rate, vascular resistance, cardiac output, and arterial pressure.