Arterial Chemoreceptors

The sections in this article are: 1 Anatomical Features 2 Physiological Characteristics 2.1 Arterial Chemoreceptors in the Fetus and Newborn 2.2 Peripheral Chemoreceptors in Adult Human Beings and Animals 2.2.1 Carotid Body Chemoreceptors 2.2.2 Aortic Chemoreceptors 2.3 Adaptation of Response to CO2 2.4 Oscillations of Chemoreceptor Activity 2.5 Effects of Exercise 2.6 Blood Pressure, Perfusate Flow, and Carotid Chemoreceptor Activity 2.7 Oxygen Consumption and Tissue PO2 2.8 Oxygen Content and Po2 in Chemoreceptor Excitation 2.9 Anesthetics and Peripheral Chemoreceptor Activity 2.10 Effects of Temperature and Tonicity 2.10.1 Temperature 2.10.2 Tonicity 2.11 Pathophysiology of Peripheral Chemoreceptors 3 Cellular Electrophysiological Mechanisms 3.1 Glomus Cells 3.1.1 Intracellular Recordings 3.1.2 Ion-Substitution Experiments 3.1.3 Effects of Temperature on MP and Ro of Glomus Cells 3.1.4 Effects of Chemical and Natural Stimuli 4 Possible Role of Carotid Body Cells as Conditioners or Inductors of Chemosensory Activity 5 Chemosensory Nerve Endings 5.1 Mass Receptor Potential of Chemoreceptors 5.2 Recordings From Single Nerve Fibers and Endings 6 Hypotheses of Chemoreception 6.1 Hypotheses Involving Neurotransmitters 6.1.1 Acetylcholine 6.1.2 Catecholamines 6.1.3 Effects of Catecholamines and Catecholaminergic Blockers 6.1.4 Serotonin 6.1.5 Adenosine Triphosphate 6.1.6 Neuropeptides 6.1.7 Possible Role of Calcium Ions in Transduction Process 6.2 Mechanoreceptor Hypotheses 6.3 Hypotheses Based on pH Sensitivity 6.4 Protein Receptor Hypothesis 6.5 Metabolic Hypothesis 7 Interactions Between Nerves and Carotid Body Cells 7.1 Result of Efferent Input on Carotid Body Afferent Output 7.1.1 Morphology of Sympathetic Efferent Input 7.1.2 Effect of Sympathetic Input on Efferent Output 7.1.3 Efferent Activity in Carotid Nerve 7.1.4 Morphology of Carotid Nerve Efferent Input 7.1.5 Sources of Efferent Activity in Carotid Nerve 7.1.6 Effects of Carotid Nerve Efferent Impulses on Carotid Body 7.2 Physiological Significance of Carotid Nerve Efferent Input 8 Peripheral Chemoreceptors and Cardiovascular Control 8.1 Chemoreceptor Stimulation in the Normoxic Animal 8.1.1 Drug Effects on Aortic and Carotid Body Chemoreceptors 8.2 Perfusion of Isolated Aortic and Carotid Chemoreceptors with Hypoxic and Hypoxic-Hypercapnic Blood 8.3 Cardiovascular Adjustments to Acute Systemic Hypoxia 8.3.1 Peripheral Arterial Chemoreceptors 8.3.2 Direct Effect of Hypoxemia on Central Nervous System 8.3.3 Effects of Hyperventilation on Cardiovascular System During Systemic Hypoxia 8.4 Chemoreceptor Activity and Regional Blood Flow 8.4.1 Species Variability 9 conclusion9 Conclusions