Atresia

Atresia is a condition in which a body orifice or passage in the body is abnormally closed or absent.

Examples of atresia include:

• Biliary atresia
• Ovarian follicle atresia, atresia refers to the degeneration and subsequent resorption of one or more immature ovarian follicles.
• Vaginal atresia – congenital occlusion of the vagina or subsequence adhesion (sticking together) of the walls of the vagina occluding it.
• Esophageal atresia – affects the alimentary tract causing the esophagus to end before connecting normally to the stomach.
• Choanal atresia – blockage of the back of the nasal passage, usually by abnormal bony or soft tissue.
• Anorectal atresia – malformation of the opening between the rectum and anus.
• Pulmonary atresia – malformation of the pulmonary valve in which the valve orifice fails to develop.
• Aural atresia (see Microtia) – a congenital deformity of the pinna (outer ear).
• Intestinal atresia – malformation of the intestine