New Latin, from Greek atelēs incomplete, defective (from a-2a- + telos end) + ektasis extension, from ekteinein to stretch out, from ex- + teinein to stretch — more at telos, thin
First Known Use: 1859
Medical Definition of ATELECTASIS
: collapse of the expanded lung; also: defective expansion of the pulmonary alveoli at birth
Lack of expansion of pulmonary alveoli (seepulmonary alveolus). With a large-enough collapsed area, the victim stops breathing. In adhesive atelectasis, obstruction or lack of surface tension keeps a newborn's alveoli from expanding. Compression atelectasis is caused by external pressure. Obstructive atelectasis may be caused by blockage of a major airway or when pain from abdominal surgery keeps breathing too shallow to clear bronchial secretions; treatment involves removal of obstruction or fluids, control of infection, and lung reinflation.