Integration of Cardiovascular Control Systems in Dynamic Exercise

The sections in this article are: 1 I. Intrinsic Properties of the Cardiovascular System: How They Permit the Rise in Cardiac Output 2 The Heart 2.1 Intrinsic Properties of the Heart 2.2 Pericardial Constraints 3 The Vascular System 3.1 Distribution of Resistance, Conductance, and Compliance 3.2 Dependency of CVP on Cardiac Output 3.3 Mechanical Effects on the Circulation—Auxiliary Pumps 3.4 Does Exercise Reduce Systemic Vascular Compliance? 3.5 Neural Control of the Vascular System during Exercise: How Important? 3.6 Balance between Mechanical and Neural Effects on Blood Flow and Blood Volume Distribution 4 II. Reflex Control of the Cardiovascular System During Dynamic Exercise: What Variables are Sensed and then Regulated by the Autonomic Nervous System During Dynamic Exercise? 4.1 Central Command 4.2 Reflexes from Active Muscles 5 Isometric Contractions: Testing Hypotheses 5.1 Isometric Contractions vs. Dynamic Exercise 5.2 Open-Loop vs. Closed-Loop Conditions 5.3 Does the Pressor Response to Voluntary Isometric Contraction have Chemoreflex or Mechanoreflex Origin? 6 Functional Importance of Muscle Chemoreflexes During Dynamic Exercise 6.1 Basic Concepts and Theory 6.2 Changes in MSNA as Evidence for Chemoreflex Activity in Dynamic Exercise 6.3 Does the Muscle Chemoreflex Initiate Increased SNA during Dynamic Exercise with Unimpaired Flow? 6.4 Does Activation of the Muscle Chemoreflex Correct Blood Flow Errors, and if so, How? 7 Baroreflex Regulation of Arterial Pressure (SAP) and Vascular Conductance in Dynamic Exercise 7.1 Does the Arterial Baroreflex Control SAP During Exercise? 7.2 Characterization and Analysis of Arterial Baroreflex Function 7.3 Baroreflex Sensitivity in Dynamic Exercise 7.4 Importance of Arterial Baroreflexes at the Onset of Exercise 7.5 Evidence Indicating “Resetting” of the Arterial Baroreflex 7.6 Central Command and Resetting of the Arterial Baroreflex—An Hypothesis 8 Role of Cardiopulmonary Baroreceptors in Dynamic Exercise 8.1 The Cardiopulmonary, or Low-Pressure, Baroreflex 8.2 Interaction between the Cardiopulmonary and Arterial Baroreflexes at Rest 8.3 Role of Cardiopulmonary Baroreflex during Dynamic Exercise 8.4 Interaction between Cardiopulmonary Baroreflex and Muscle Chemoreflex 8.5 Interaction between Cardiopulmonary and Arterial Baroreflexes in Exercise 8.6 Importance of Cardiopulmonary Baroreflexes during Dynamic Exercise 9 Control of the Circulation During Exercise and Heat Stress: Competing Reflexes 9.1 Cardiovascular Demands of Heat Stress 9.2 Overall Neural Control of the Cutaneous Circulation 9.3 Reflex Control of the Cutaneous Circulation during Exercise 9.4 Baroreflex v. Thermoregulatory Reflex Control of the Cutaneous Circulation during Exercise 10 How Does Physical Conditioning Alter Cardiovascular Function? 10.1 Range of Adjustment in Overall Cardiovascular Function 10.2 What Cardiovascular Adjustments Explain the Rise in ? 10.3 How does Maximal SV Increase with Physical Conditioning? 10.4 Does Physical Conditioning Change Autonomic Control of the Circulation? 11 Synthesis 11.1 What is the Autonomic Nervous System Controlling during Exercise? 11.2 What Errors Are Sensed and then Corrected by the Autonomic Nervous System during Exercise?