A couple of weeks ago, one of my family members had a stroke. Among the many things I didn’t know about strokes is that if you have one, you might lose the ability to swallow properly. It’s turns out, there is a very complex series of steps that have to occur in just the right way for a person to swallow without inhaling the food or liquid they’re trying to get down.
From Gould’s Pathophysiology for the Health Professions - 5th Edition - Page 432
“When food is ready to be swallowed, the tongue pushes the bolus of food
back to the pharyngeal wall, where receptors of the trigeminal and glossopharyngeal nerves relay the information to the swallowing center in the medulla.
Because the reflex is activated at this point, deglutition becomes an involuntary activity. The swallowing center coordinates the actions required to move food or fluid into the stomach, without aspiration into the lungs, by means of cranial nerves 5, 9, 10, and 12 in the following steps:
The soft palate is pulled upward
The vocal cords are approximated
The epiglottis covers the larynx
The bolus is seized by the constricted pharynx
As the bolus of food moves into the esophagus, distending the wall, peristalsis is initiated, pushing the food down the esophagus.
The distal part of the esophagus passes through the hiatus in the diaphragm to join the stomach in the abdominal cavity.
The lower esophageal sphincter relaxes in advance of the bolus, allowing it to drop into the stomach.
Links:
- Contact Us: Level 989
- Gould's Pathophysiology for the Health Professions, 5th Edition - 9781455754113
- Swallowing problems after stroke fact sheet — Stroke Foundation - Australia
- Difficulty Swallowing After Stroke (Dysphagia)
- Saliva - Wikipedia
- Feeding and Swallowing