Definition of atresia in US English:



  • 1Medicine
    Absence or abnormal narrowing of an opening or passage in the body.

    • ‘The main objective of our study was to identify chromosomal regions possibly containing putative disease loci involved in the etiology of anal atresia.’
    • ‘Cheryl was diagnosed with pulmonary atresia as a baby, and underwent two heart operations when she was six-months-old and five.’
    • ‘Mary has pulmonary atresia, a condition that means the heart and the main blood vessel to the lungs have failed to develop properly.’
    • ‘The Foundation is of vital importance to Sarah and her family because her youngest daughter, Carol, was diagnosed last year with a rare liver disease called biliary atresia.’
    • ‘An X-ray revealed she had a condition called trachea oesophageal fistula and atresia, where the oesophagus and windpipe have not split properly.’
  • 2Physiology
    The degeneration of those ovarian follicles which do not ovulate during the menstrual cycle.

    • ‘This results in atresia of the dominant follicle and re-initiation of follicular recruitment.’
    • ‘The process by which follicles degenerate and disappear is little understood and is termed follicular atresia.’
    • ‘Furthermore, they may cause premature depletion of the follicle pool by induction of follicular atresia or oocyte apoptosis and, thereby, lead to reduced fertility.’
    • ‘These structures form through a process of follicular atresia accompanied by hypertrophy of the follicular cells.’
    • ‘Mammalian females have a fixed number of oocytes at birth, which decreases dramatically with advancing age due to follicular atresia.’


Early 19th century: from a- ‘without’ + Greek trēsis ‘perforation’ + -ia.