HLSC 2461U Lecture Notes - Hemoptysis, Asbestosis, Mesothelioma
Document Summary
Some infants are born with this and could go into respiratory failure very quickly (premature) A very thin layer of liquid compounds that is covering all the cells in the alveolar cavity. Produced by type 2 alveolar cells which have laminar inclusion bodies which secrete it. Composed of molecules that decrease surface tension. Produced around week 28 of gestation (born before this = no surfactant) At week 24, laminar bodies are present along with type 2 pneumocytes or in the cuboidal epithelium. If cells do not have surfactant, it induces surface tension that tends to close the alveoli. Surface tension exerts forces that tend to close the alveoli in the absence of surfactant. There is now a tendency for atelectasis (collapse) When surfactant is present, it decreases surface tension and allows the alveoli to open. You see the immature lungs, the atelectasis, and that ultimately ends in respiratory failure.
