Peristaltiska

Peristaltiska (peristalsis) describes a coordinated, wave-like contraction of smooth muscle that propels contents through tubular organs. The term is used in physiology and medicine to describe how the gut and other ducts move liquids and semi-solid material along their lumen. Peristaltic activity is generated by smooth muscle layers arranged circularly and longitudinally, and is coordinated by the enteric nervous system, notably the myenteric plexus, with modulation from the vagus nerve and local hormonal signals.

In the esophagus, peristalsis begins with swallowing, producing primary peristaltic waves that push the bolus toward the stomach; if needed, secondary peristalsis is induced by luminal distension. In the small and large intestines, peristalsis moves contents along while segmented contractions mix them for digestion. Peristaltic waves are interspersed with segmentation in the small intestine to optimize absorption.

Peristalsis also occurs in other tubular organs, including the ureters, urethra, and fallopian tubes, where rhythmic contractions help move urine or gametes. In laboratory and clinical settings, peristaltic pumps use flexible tubing and rollers to transport fluids by mimicking natural peristaltic motion.

Disorders of peristalsis can affect transit speed and luminal patency. Examples include achalasia, with impaired esophageal peristalsis and LES dysfunction; scleroderma-related loss of esophageal contractions; ileus; and colonic inertia. Diagnosis often involves manometry or imaging studies, and treatment may include prokinetic medications or surgical or endoscopic interventions to restore or bypass impaired propulsion.