Standard Article

Respiratory Gas Exchange in the Placenta

Handbook of Physiology, The Respiratory System, Gas Exchange

  1. Lawrence D. Longo

Published Online: 1 JAN 2011

DOI: 10.1002/cphy.cp030418

Comprehensive Physiology

Comprehensive Physiology

How to Cite

Longo, L. D. 2011. Respiratory Gas Exchange in the Placenta. Comprehensive Physiology. 351–401.

Author Information

  1. Division of Perinatal Biology, Departments of Physiology and Obstetrics and Gynecology, School of Medicine, Loma Linda University, Loma Linda, California

Publication History

  1. Published Online: 1 JAN 2011

Abstract

The sections in this article are:

  • 1
    The Placenta
    • 1.1
      Placental Exchange and Fetal Oxygenation
    • 1.2
      Questions to Consider
  • 2
    Maternal Blood O2 Affinity and Capacity
    • 2.1
      Hemoglobin
    • 2.2
      Blood O2 Affinity and HbO2 Saturation Curve
    • 2.3
      Blood O2 Capacity
  • 3
    Fetal Blood O2 Affinity and Capacity
    • 3.1
      Fetal Hb
    • 3.2
      Blood O2 Affinity
    • 3.3
      Blood O2 Capacity
  • 4
    Interrelations of Maternal and Fetal Blood O2 Affinity and Capacity
    • 4.1
      General Considerations
    • 4.2
      Species Differences
  • 5
    Transplacental Diffusion
    • 5.1
      Mean Maternal-to-Fetal O2 Tension Differences
    • 5.2
      Placental Diffusing Capacity
    • 5.3
      Role of Hb Reaction Rates
    • 5.4
      Possible Facilitated O2 Transport
    • 5.5
      Alterations in Placental Diffusing Capacity
    • 5.6
      Placental O2 Consumption
    • 5.7
      Summary
  • 6
    Variations in Maternal and Fetal O2 Tensions
    • 6.1
      Theoretical Considerations
    • 6.2
      Experimental Studies
    • 6.3
      Clinical Implications
  • 7
    Variations in Maternal and Fetal O2 Affinity
    • 7.1
      Theoretical Considerations
    • 7.2
      Decrease in Fetal Blood O2 Affinity by Intrauterine Transfusion
    • 7.3
      Changes in O2 Affinity Due to Hemoglobinopathies
    • 7.4
      Maternal Hyperventilation
    • 7.5
      Carbon Monoxide Effects
  • 8
    Placental CO2 Exchange
    • 8.1
      Forms of CO2
    • 8.2
      Carbon Dioxide Dissociation Curves
    • 8.3
      Transplacental CO2 Exchange
    • 8.4
      Haldane and Bohr Effects
    • 8.5
      Importance of Various Factors on CO2 Exchange
    • 8.6
      Umbilical-to- Uterine Venous CO2 Tension Differences
    • 8.7
      Interrelations of Placental CO2 and H2O Exchange
    • 8.8
      Conclusions
  • 9
    Variations in Rate of Maternal and Fetal Placental HB and O2 Flows
    • 9.1
      General Considerations
    • 9.2
      Theoretical Considerations
    • 9.3
      Experimental Studies
    • 9.4
      Clinical Implications of Altered Placental Flows
  • 10
    Interrelations of Maternal and Fetal Placental Flows and O2 Exchange
    • 10.1
      Distribution of Maternal and Fetal Placental Flows
    • 10.2
      “Sluice” or “Waterfall” Flow in Placental Vessels
    • 10.3
      Uterine Contractions and O2 Exchange
    • 10.4
      Importance of Various Parameters in O2 Transfer
    • 10.5
      Summary Equations
    • 10.6
      Graphical Analysis of Placental O2 and CO2 Exchange
  • 11
    Some Comparisons of Blood Flow and Gas Exchange in the Placenta and Lung
  • 12
    Conclusions