Atresia

Absence or closure of a natural body passage. May also refer to loss of a body part through degeneration.

A congenital medical condition in which a body orifice or passage in the body is abnormally closed or absent.

Abnormal closure of an anatomic opening; absence of opening from birth.

An unusual closing or absence of a tube in the body.

Lack or malformation of a normal body opening, often requiring surgical correction.

Condition in which a normal opening or tube in the body (e.g., the urethra) is closed or absent.

Absence of a normal orifice, duct, or canal such as the auditory or biliary canals.

From birth, the absence of a normal body opening or the abnormal closure of an opening. Examples of atresia include a closed anus, the absence or closure of the outer ear canal, and narrowing of certain blood vessels.

Congenital absence or abnormal narrowing of a body opening. Biliary atresia (affecting the bile duct) causes obstructive jaundice in infancy and is lethal unless corrected surgically; tricuspid atresia obstructs the blood flow within the heart from the right atrium to the right ventricle.

The absence of a natural opening, or closure of it by a membrane. Thus atresia may be found in newborn infants, preventing the bowels from moving. In young girls after puberty, absence of the menstrual flow may be due to such a malformation at the entrance to the vagina.

Congenital absence or closure of a normal body opening or tubular structure.

Congenital atresia refers to the absence or severe narrowing of a body opening or tubular organ that is present from birth. This condition occurs due to developmental failures in the uterus. Examples of congenital atresia include biliary atresia, where the bile ducts connecting the liver and duodenum are absent, oesophageal atresia, which results in the oesophagus terminating as a blind end, and anal atresia, where the anal canal is closed off. Most cases of atresia require surgical intervention during early infancy to rectify the condition.