From Big Medical Encyclopedia

ACHALASIA (achalasia; grech, and - otritsa. + chalasis relaxation) — disturbance of ability of relaxation of the muscular sphincters located in a transition range of tubular body in hollow (a gullet in a stomach, an ureter in a bladder). At And. there is no synchronous reflex disclosure of a transition range, but under the influence of mechanical influence of a food lump or a column of urine the muscular sphincter can partially reveal.

Reasons And. are studied insufficiently. Specific data on And. separate bodies — see. Cardiospasm , Ureter .

A. E. Podolsky.