You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Non progressive contraction of Esophagus are: and explain in detail?
• Tertiary contractions are simultaneous, non progressive, non peristaltic waves that can occur throughout the esophagus
• Tertiary contractions represent uncoordinated contractions of the smooth muscles that are responsible for the ‘Cork Screw’ appearance of esophageal spasm on Barium swallow
• Tertiary contractions do not have a physiological function and may be observed in the elderly and in patients with esophageal motility disorders