Sensory afferents from the gastrointestinal tract

The sections in this article are: 1 Visceral Nerves as Sensory Nerves 1.1 Pathways to the Central Nervous System 1.1.1 Central Connections of the Abdominal Vagus 1.1.2 Projections of the Nucleus Tractus Solitarius 1.1.3 Central Connections of Splanchnic and Pelvic Nerves 2 Classification of Gastrointestinal Receptors 3 Sensory Code 4 Methodology 5 Mucosal Receptors 5.1 Spontaneous Activity 5.2 Mechanosensitivity 5.3 Receptive Fields 5.4 Chemosensitivity 5.4.1 Multimodal Receptors 5.4.2 Quality-Specific Chemoreceptors 5.5 Thermoreceptors 6 Muscle Receptors 6.1 In-Series Tension Receptors 6.1.1 Resting Discharge 6.1.2 Response Characteristics 6.1.3 Regional Differences 6.1.4 Longitudinal Versus Circular Muscle Location 6.1.5 Muscle Receptors with Nonvagal Afferent Pathways 7 Serosal and Mesenteric Receptors 7.1 Receptive Fields 7.2 Spontaneous Activity 7.3 Response Characteristics 8 Functional Specificity and Transduction of Stimuli 9 Spontaneous Activity in Gastrointestinal Afferents 10 Rate of Adaptation 11 Modulation of Receptor Activity 12 Functional Significance of Gastrointestinal Receptors 12.1 Mucosal Receptors 12.2 Muscle Receptors 13 Serosal and Mesenteric Receptors 14 Conclusions