Source:http://linkedlifedata.com/resource/umls/id/C0034059
MSH: The amount of a gas taken up, by the pulmonary capillary blood from the alveolar gas, per minute per unit of average pressure of the gradient of the gas across the BLOOD-AIR BARRIER.,CSP: processes of diffusion across the blood-air barrier and the chemical reactions coupled with diffusion that effect the rate of pulmonary gas exchange, generally at the alveolar level.