There is probably no other area of clinical medicine in which alterations in respiratory function occur so often, so quickly, and for such varied reasons as in the patient subject to anesthesia and operative treatment. In this area, then, there is a definite and important but unfortunately, insufficiently emphasized relationship between surgery and basic biology. To further establish this relationship, some elements of basic respiratory physiology need to be considered.
Respiratory function is dependent upon a very complex arrangement which includes at least (1) neurosensory elements, (2) central integration in the brain, (3) neuromuscular effectors (neurotransmission, neuromuscular transmission, musculoskeletal function), and (4) ventilation of the lung (movement of gas, circulation).
The neurosensory elements detect changes of a chemical or physical nature in the bloodstream or in special cells, send these to brain centers where the signal is integrated with signals from other areas of the body, and the brain centers,
Hamilton WK. Alterations in Pulmonary Functions. JAMA. 1967;202(12):1090. doi:10.1001/jama.1967.03130250072012