Control of the central swallowing program by inputs from the peripheral receptors. A review

doi:10.1016/0165-1838(84)90017-1

Journal of the Autonomic Nervous System

Volume 10, Issues 3–4, May–June 1984, Pages 225-233

Journal of the Auton...

https://doi.org/10.1016/0165-1838(84)90017-1 Get rights and content

Abstract

Swallowing is a complex motor sequence, usually divided into a buccopharyngeal stage (coordinated contractions of several muscles of the mouth, pharynx and larynx) and an esophageal stage, called primary peristalsis. This motor sequence depends on the activity of medullary interneurons belonging to the swallowing center which program through excitatory and inhibitory connections the sequential excitation of motoneurons and vagal preganglionic neurons responsible for the whole motor sequence. The activity of the medullary swallowing neurons can occur without feedback phenomena: it is truly a central activity indicating that swallowing depends on a central network which may function without afferent support.

However, the swallowing neurons receive a strong afferent input suggesting the involvement of sensory feedbacks during swallowing. The swallowing neurons present a short latency activation on electrical stimulation of the peripheral afferent fibers supplying the region of the tract which is under their control. In addition, the neurons are activated by localized distensions of the swallowing tract, this distension having to be done more and more distally when the neuronal discharge occurs later and later during swallowing. Furthermore the swallowing discharge of the central neurons is increased either when a bolus is swallowed or during a slight distension of the corresponding region of the tract. Thus, under physiological conditions, swallowing neurons receive sensory information from pharyngeal and esophageal receptors and the central program may be modified by peripheral afferents that adjust the motor sequence to the size of the swallowed bolus.

The inputs from the peripheral receptors can also exert inhibitory effects depending on the central connections between the swallowing neurons. Indeed all the esophageal neurons are inhibited either during the buccopharyngeal stage or a pharyngeal distension which stimulate the peripheral receptors. In addition, the very late neurons are also inhibited during the contraction or a distension of the proximal part of the esophagus which activate the esophageal receptors.

It can be concluded, that, although swallowing is a centrally programmed motor sequence, the inputs from the peripheral receptors can control the complete motor sequence through sensory feedback.

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View full text

Control of the central swallowing program by inputs from the peripheral receptors. A review

Abstract

Brain Res. Bull.

Gastroenterology

Gastroenterology

Brain Res.

Brain Res.

The nervous control of cervical oesophagus of the rat

J. Physiol. (Lond.)

Esophageal motility after vagotomy, phrenicotomy, myotomy and myomectomy in dogs

Surg. Gynecol. Obstet.

Vagal mechanoreceptors located in the lower oesophageal sphincter of the cat

J. Physiol. (Lond.)

A comparison between primary esophageal peristalsis following wet and dry swallows

J. appl. Physiol.

Neural organization of deglutition

An electromyographic analysis of reflex deglutition

J. Neurophysiol.

The Neural Basis of Oral and Facial Function

Reinnervation of skeletal muscles by vagal sensory fibres in the sheep, cat and rabbit

J. Physiol. (Lond.)

Vagal mechanoreceptors of the inferior thoracic oesophagus, the lower oesophageal sphincter and the stomach in sheep

Pflüger's Arch. ges. Physiol.

The effect of sympathectomy, vagotomy and esophageal interruption on the canine gastro-esophageal sphinter

Thorax

Physiology

Effect of dry swallows and wet swallows of different volumes on esophageal peristalsis

J. appl. Physiol.