TY  - JOUR
PY  - 1998//
TI  - Effects of lung volume and involuntary breathing movements on the human diving response
JO  - European journal of applied physiology and occupational physiology
A1  - Andersson, J.
A1  - Schagatay, E.
SP  - 19
EP  - 24
VL  - 77
IS  - 1-2
N2  - The effects of lung volume and involuntary breathing movements on the human diving response were studied in 17 breath-hold divers. Each subject performed maximal effort apnoeas and simulated dives by apnoea and cold water face immersion, at lung volumes of 60%, 85%, and 100% of prone vital capacity (VC). Time of apnoea, blood pressure, heart rate, skin capillary blood flow, and fractions of end-expiratory CO2 and O2 were measured. The length of the simulated dives was the shortest at 60% of VC, probably because at this level the build up of alveolar CO2 was fastest. Apnoeas with face immersion at 100% of VC gave a marked drop in arterial pressure during the initial 20 s, probably due to high intrathoracic pressure mechanically reducing venous return. The diving response was most pronounced at 60% of VC. We concluded that at the two larger lung volumes both mechanical factors and input from pulmonary stretch receptors influenced the bradycardia and vasoconstriction, resulting in a nonlinear relationship between the breath-hold lung volume and magnitude of the diving response in the near-VC range. Furthermore, the involuntary breathing movements that appeared during the struggle phase of the apnoeas were too small to affect the diving response.<p /> <p>Language: en</p>
LA  - en
SN  - 0301-5548
UR  - http://dx.doi.org/
ID  - ref1
ER  -