What is peristalsis please give long answer​

successive waves of involuntary contraction passing along the walls of a hollow muscular structure (such as the esophagus or intestine) and forcing the contents onward.

Peristalsis is a series of wave-like muscle contractions that move food through the digestive tract. It starts in the esophagus where strong wave-like motions of the smooth muscle move balls of swallowed food to the stomach

Peristalsis is a series of muscle contractions that propagates a wave down a tube in the alimentary canal and allows the movement of food. In the

gastrointestinal tract of humans, the smooth muscle contracts to produce a peristaltic wave which propels the bolus (a ball of food) into the oesophagus