Interaction of Cardiovascular Reflexes in Circulatory Control

Abstract

The sections in this article are: 1 Determinants of Neurogenic Control 2 Definitions 2.1 Cardiovascular Reflex Arc 2.1.1 Sensory Neurons 2.1.2 Central Neurons 2.1.3 Modulating Neurons 2.1.4 Vagal and Sympathetic Preganglionic Neurons 2.2 Open-Loop Versus Closed-Loop Response 2.3 Types of Interactions 2.3.1 Summation of Similar Responses 2.3.2 Summation of Opposite Responses 2.3.3 Set Point and Gain of Reflex 2.3.4 Effector Responsiveness Versus Neural Interactions 3 Central Nervous System Substrate 3.1 Medullary Nuclei 3.1.1 Medullary Inhibitory (Depressor) Regions 3.1.2 Medullary Excitatory (Pressor) Regions 3.1.3 Nucleus Tractus Solitarius 3.1.4 Functional Role of NTS and Other Brain Stem Nuclei in Cardiovascular Control 3.2 Hypothalamus and Cardiovascular Control 3.2.1 Electrical Stimulation of Hypothalamus 3.2.2 Stimulation of Posterolateral Hypothalamus Pressor Area 3.2.3 Stimulation of Anterior Hypothalamus Depressor Area 3.2.4 Locomotor Behavior and Central Command 3.2.5 Central Command Versus Somatic Afferents During Exercise 3.2.6 Interactions of Hypothalamus with Baroreceptors and Chemoreceptors 3.2.7 Facilitating or Suppressing Reflex Responses by Hypothalamic Stimulation 3.3 Inferior Olive: Suppression of Baroreflex 3.4 Cerebellar Control: Hypothalamic and Baroreceptor Interactions 3.5 Suprabulbar and Cortical Connections 3.6 Sleep and Sinoaortic Reflexes 3.7 Respiratory Influences on Baroreceptor Control of Vagal Neurons 3.8 Spinal Preganglionic Sympathetic Neurons 3.8.1 Brain Stem-Spinal Cord Connections 3.8.2 Excitatory Control 3.8.3 Inhibitory Control 3.9 Medullary Preganglionic Vagal Neurons to Heart 3.10 Neuropeptides: Regulation of Arterial Pressure 3.11 Brain Amines: Reflex Control 3.11.1 Catecholamines 3.11.2 Dopamine 3.11.3 Ventilatory Responses to Catecholamines 4 Cardiovascular Reflexes that Might Interact 4.1 Sinoaortic Baroreflexes 4.2 Cardiac Receptors With Afferent Vagal Fibers 4.3 Cardiac Receptors With Afferent Sympathetic Fibers 4.4 Reflexes Originating From Chemoreceptor Stimulation 4.4.1 Central Projection 4.4.2 Responses 4.4.3 Selectivity of Vascular Responses 4.4.4 Suppression of Cardiovascular Effects: Hyperventilation 4.4.5 Potentiation of Responses 4.4.6 Depression of Response: Dopamine 4.4.7 Comparison of Responses to Baroreceptor and Chemoreceptor Nerve Stimulation 4.4.8 Chemoreceptor Mediation of Sustained and Prolonged Stimulation of Respiration by Central Neural Mechanism 4.5 Reflexes Originating in Lung 4.5.1 Pulmonary Arterial Baroreceptors 4.5.2 Slowly Adapting Stretch Receptors: Lung Inflation Reflex 4.5.3 Pulmonary and Bronchial C Fibers 4.5.4 Sympathetic Afferents 4.6 Reflexes Originating In Skeletal Muscle During Exercise 4.6.1 Baroreceptor Reflex During Exercise 4.6.2 Cardiovascular Responses and Blood Flow Distribution 4.7 Reflexes Originating From Facial and Upper Airway Receptors: Diving Reflex 4.7.1 Upper Airway 4.7.2 Relative Contributions of Apnea and Immersion 4.8 Vestibulocerebellar Reflexes 5 Interaction of Specific Reflexes in Autonomic Control of Circulation 5.1 Selectivity and Nonuniformity of Autonomic Control When One Sensory Afferent Input is Activated or Withdrawn 5.1.1 Mechanisms of Selectivity 5.1.2 Examples of Selectivity and Nonuniformity 5.2 Simultaneously Activating Sensory Stimuli 5.2.1 Stimulating Two Opposing Reflexes 5.2.2 Modifying Reflex Gain by Changing Tonic Influence of One Set of Sensory Afferents 5.3 Redundancy in Baroreceptor Control of Preganglionic Neurons 5.3.1 Restraint of Resting Arterial Pressure, Vascular Resistance, and Heart Rate by Various Afferents 5.3.2 Reflex Responses to Phenylephrine and Nitroglycerin after Selectively Denervating Baroreceptors 5.3.3 Limited Use of Volume Expansion to Test Arterial Baroreflexes 5.3.4 Acute Versus Chronic Denervation of Baroreceptor Afferents 5.4 Sensitizing Sensory Receptors and Modulating Efferent Sympathetic Neurotransmission 5.4.1 Sensitizing Sensory Receptors 5.4.2 Modulating Efferent Sympathetic Neurotransmission 5.5 Regulating Renin and Vasopressin 5.5.1 Reflex Control of Renin Secretion 5.5.2 Reflex Control of Vasopressin Secretion 6 Clinical Implications 6.1 Integrated Neural Responses to Myocardial Ischemia and Infarction 6.2 Interaction of Reflexes in Heart Failure 6.2.1 Humoral Factors: Renin, Angiotensin, Aldosterone, and Antidiuretic Hormone 6.2.2 Sympathetic and Parasympathetic Innervation 6.2.3 Cardiovascular Reflexes 6.3 Reflex Interactions in Hypertension 6.3.1 Arterial Baroreceptors 6.3.2 Cardiac Afferents 6.3.3 Renal Afferents 7 conclusion7 Conclusion