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%.
In a similar study, injection into the costotranverse joints did not produce chest wall pain. 10 The innervation of the costovertebral joints suggests that pain in these joints could be referred to the anterior chest 11 but this has not been tested.