THE EFFECT OF INDUCED HYPOXIA ON THERMOREGULATION AND CARDIOPULMONARY FUNCTION

Abstract

The effect of induced hypoxia on body temperature regulation and cardiopulmonary function is assessed in anesthetized dogs under warm, neutral and cold environments. Hypoxia acts differently to heat conservation (shivering) and heat dissipation (thermal panting) mechanisms: the former is suppressed, while the latter is facilitated. It is also found that the suppression of shivering is partly due to the hypocapnia which is produced under hypoxia. The lethal threshold of acutely induced hypoxia is at the inspiratory O2 level of approximately 3% in the neutral and cold environments, whereas it is at 5% in the warm environment. Under hypoxia, the total ventilation is increased two- to threefold. The alveolar ventilation, however, is augmented to a lesser degree with a progressive increase in physiological dead space. Contrary to respiration, the cardiac output is only slightly increased (less than 30% over the control value) under hypoxia.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1963
Accession Number
AD0406620

Entities

People

  • T. P. Lim
  • U. C. Luft

Organizations

  • Lovelace Foundation

Tags

DTIC Thesaurus Topics

  • Air Breathing
  • Arteries
  • Blood
  • Body Temperature
  • Body Temperature Regulation
  • Body Weight
  • Brain
  • Cardiovascular Physiological Phenomena
  • Climate Change
  • Elevation
  • Heart Rate
  • Intensity
  • Measurement
  • Partial Pressure
  • Plastic Explosives
  • Sweating
  • Vapor Pressure

Readers

  • Cardiovascular Physiology
  • Thermal Physics or Thermal Science.

Technology Areas

  • Space
  • Space - Hall-Effect Thruster