Sväljningsmuskulaturen

Sväljningsmuskulaturen, also known as the muscles of deglutition, refers to the complex set of voluntary and involuntary muscles that work together to facilitate the process of swallowing. This coordinated action allows food and liquids to move from the mouth, through the pharynx and esophagus, and into the stomach.

The process of swallowing is divided into three phases: the oral phase, the pharyngeal phase, and the esophageal phase. The oral phase is voluntary and involves the muscles of the tongue, cheeks, and jaw to manipulate food and form a bolus. The tongue then propels the bolus backward towards the pharynx.

The pharyngeal phase is largely involuntary and is triggered by the presence of the bolus in the pharynx. A complex interplay of muscles in the pharynx and larynx elevates the larynx, closes off the airway (epiglottis covers the trachea), and constricts the pharyngeal muscles to push the bolus downwards. Muscles such as the pharyngeal constrictors, stylopharyngeus, and palatopharyngeus are crucial here.

The esophageal phase is also involuntary. Once the bolus enters the esophagus, the upper esophageal sphincter relaxes, and peristalsis, a series of wave-like muscular contractions, propels the bolus down the esophagus towards the stomach. The lower esophageal sphincter then relaxes to allow the bolus to enter the stomach. Maintaining the function of sväljningsmuskulaturen is vital for nutrition and hydration.