37. The physiology of high altitude and diving
37. The physiology of high altitude and diving
- Gillian Pocock, Gillian PocockSenior Lecturer in Clinical Science, Canterbury Christ Church University, Canterbury, UK
- Christopher D. RichardsChristopher D. RichardsEmeritus Professor of Experimental Physiology, Division of Physiology, Pharmacology and Neuroscience, Faculty of Life Sciences, University College London, London, UK
- and David A. RichardsDavid A. RichardsAssociate Professor, Department of Basic Pharmaceutical Sciences, Husson University School of Pharmacy, Bangor, Maine, USA
Abstract
This chapter describes the physiology of the cardiovascular and respiratory systems under the stresses imposed by changes to ambient pressure. It refers to the physiological adaptations which occur when a person experiences the reduced atmospheric pressure of high altitudes. It also looks at the respiratory problems associated with high ambient atmospheric pressures, such as those experienced by divers. The chapter clarifies how atmospheric pressure decreases with altitude and how the partial pressure of oxygen in the inspired air falls progressively with increasing altitude as the fraction of oxygen in the air does not change. The hypoxia of altitude can be divided into acute hypoxia, which is experienced by subjects who have been exposed to high altitude for a few minutes or hours, and chronic hypoxia, which is experienced by people living for long periods at high altitude or by mountaineers who have become acclimatized to high altitude.
