Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.583078
Title: The control of breathing at high altitude
Author: Milledge, J. S.
Awarding Body: University of Birmingham
Current Institution: University of Birmingham
Date of Award: 1968
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Abstract:
The changes in the control of breathing in man at high altitude have been studied at 5,800 m (19,000 ft). The differences between 1owlanders and Sherpas were compared at 4,880 m (16,000 ft.). Ventilatory response to C0\(_2\), hypoxia and exercise were studied, and acid-base status of the blood and CSF measured. Acclimatization to altitude is characterized by a shift of the C0\(_2\) response curve to the left and an increase in its slope. The hypoxic sensitivity appears unchanged. On moderate exercise there results a progressive increase in ventilatory equivalent with increasing altitude. At maximum work rate ventilation increases more rapidly due to falling Sao\(_2\). Sherpas show no significant difference in response to C0\(_2\) but a remarkable lack of response to hypoxia. The C0\(_2\) response showed little change in slope with change of P0 \(_2\) and on exercise acutely changing PO\(_2\)had little effect on ventilation. Sherpas ventilate less on exercise and have higher maximum 0\(_2\) intakes per kg than lowlanders. The arterial pH of highlanders is normal whereas in lowlanders it remains slightly elevated after k-6 weeks at altitude. CSF pH of highlanders is about 0.04 units more acid than lowlanders at the same altitude, indicating a greater central contribution to respiratory drive and a reduced peripheral component. The role of anaerobic cerebral metabolism in respiratory acclimatization is discussed.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (M.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.583078  DOI: Not available
Keywords: R Medicine (General)
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