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HEALTH

The Claim

During acute stress, pulmonary blood flow increases mainly because cardiac output increases.

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The Short Version

The central mechanism is correct for typical acute stress in healthy people: sympathetic activation raises cardiac output, and pulmonary blood flow usually rises with it. The statement becomes too broad if applied to all stressors or all patients, because acute hypoxia and diseases such as severe pulmonary hypertension can make pulmonary vascular resistance or right-heart afterload more important.

Caveats

  • The claim should be read as applying mainly to healthy physiology and common stress responses such as exercise or psychological arousal.
  • Acute hypoxia is a notable exception: pulmonary vascular constriction can raise pulmonary pressures without cardiac output being the main driver.
  • In severe pulmonary hypertension or other cardiopulmonary disease, increased pulmonary resistance and right-ventricular afterload can blunt or alter the expected flow increase.

The Receipts

  1. Autonomic control of the pulmonary circulation

    The Journal of Physiology (NIH PMC)

  2. Sympathetic Neural Mechanisms in Human Cardiovascular Health and Disease

    Circulation (NIH PMC)

  3. A change of heart: Mechanisms of cardiac adaptation to acute and chronic hypoxia

    The Journal of Physiology

  4. Cardiovascular Effects and Benefits of Exercise

    Frontiers in Cardiovascular Medicine (PMC/NIH)

  5. Circulating Catecholamines

    Cardiovascular Physiology Concepts

  6. Cardiovascular reactions to acute psychological stress and academic achievement

    Psychophysiology (via PMC)

  7. Mental stress increases right heart afterload in severe pulmonary hypertension

    PubMed (Journal of the American College of Cardiology)

  8. Physiology Tutorial - Cardiovascular Function

    University of Minnesota Visible Heart® Lab

  9. Neural Activation of the Heart and Blood Vessels

    CV Physiology (Richard E. Klabunde)

  10. Responses of the Respiratory System to Stress

    TeachMePhysiology

+ 7 more sources — see the full list on Lenz

Filed Under

Acute StressCardiac OutputPulmonary Blood Flow

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