A key process in surfactant secretion is exocytosis of LB, and there have been several ultrastructural observations of lamellar material passing from AT II cells into alveoli (reviewed in ref.
In one general practice sample, costochondritis, also known as costosternal syndrome and anterior chest wall syndrome, was the most common specific cause of anterior musculoskeletal chest pain, with a prevalence of 13%.
Costochondritis is inflammation of the junctions where the upper ribs join the cartilage that attaches them to the breastbone (sternum). Costochondritis causes localized chest wall pain and tenderness that can be reproduced by pushing on the involved cartilage in the front of the rib cage. Costochondritis is a relatively harmless musculoskeletal chest pain and usually resolves without treatment. The cause is usually unknown.