What is atresia?

Answer 1

* Anal atresia -- congenital absence of a hole at the bottom end of the intestine. Also called imperforate anus. * Aortic atresia -- congenital absence of the normal valvular opening into the aorta. * Biliary atresia -- absence of the major bile ducts. * Choanal atresia -- congenital failure of one or both nasal passages to open. * Esophageal atresia -- a birth defect in which part of esophagus is not hollow. * Intestinal atresia -- obliteration of the hollow of the small intestine, involving the ileum (50% of cases) or the jejunum or duodenum. * Laryngeal atresia -- congenital failure of the laryngeal opening to develop, resulting in partial or total obstruction at or just above or below the glottis. * Pulmonary atresia -- congenital absence of the pulmonary valve opening in the heart. * Tricuspid atresia -- congenital lack of the tricuspid valve opening. * Vaginal atresia -- congenital occlusion of the vagina or subsequence adhesion (sticking together) of the walls of the vagina occluding it.

Answer 2

It is the absence of the external ear canal