Sväljningsfunktionerna

Sväljningsfunktionerna, often referred to as swallowing functions, encompass the complex physiological processes involved in moving food, liquid, or saliva from the mouth to the stomach. This intricate process can be broadly divided into four stages: oral preparation, oral transit, pharyngeal transit, and esophageal transit.

The oral preparation stage involves chewing and manipulating food or liquid in the mouth to form a cohesive bolus. This includes tasting, sensory feedback, and the production of saliva, which aids in lubrication and initial digestion.

The oral transit stage is the voluntary movement of the bolus from the front of the mouth to the pharynx. This is achieved through the action of the tongue, which propels the bolus backward.

The pharyngeal transit stage is an involuntary reflex triggered when the bolus reaches the pharynx. This stage involves a rapid sequence of muscle contractions that propel the bolus downward, simultaneously closing off the airway to prevent aspiration. Key actions include the elevation of the soft palate, forward movement of the larynx, and relaxation of the upper esophageal sphincter.

Finally, the esophageal transit stage involves the involuntary passage of the bolus down the esophagus to the stomach via peristalsis, a series of wave-like muscular contractions. The lower esophageal sphincter then relaxes to allow the bolus to enter the stomach. Each stage is crucial for safe and efficient swallowing, and dysfunction at any point can lead to dysphagia, or difficulty swallowing.