sväljningssekvensen

Sväljningssekvensen, also known as the swallowing sequence, refers to the highly coordinated series of events that occur when food or liquid is moved from the mouth to the stomach. This complex physiological process involves a precise interplay of muscles in the mouth, pharynx, and esophagus, as well as neurological control. The sequence is typically divided into three phases: oral, pharyngeal, and esophageal.

The oral phase is voluntary and involves chewing and manipulating the bolus of food or liquid within the mouth. The tongue then propels the bolus towards the pharynx. The pharyngeal phase is involuntary and begins when the bolus triggers sensory receptors in the pharynx. This phase involves rapid and protective reflexes, including the elevation of the soft palate to block the nasal cavity, the closure of the epiglottis over the larynx to prevent aspiration into the airway, and the contraction of pharyngeal muscles to propel the bolus downwards.

The final esophageal phase is also involuntary. Once the bolus enters the esophagus, peristalsis, a wave of muscular contractions, moves it down towards the stomach. The lower esophageal sphincter relaxes to allow the bolus to enter the stomach and then closes to prevent reflux. Disruptions at any stage of the sväljningssekvensen can lead to dysphagia, or difficulty swallowing.