Physiology, Oxygen Transport

Carl E. Rhodes, Deanna Denault, Matthew Varacallo, Carl E. Rhodes, Deanna Denault, Matthew Varacallo

Excerpt

Oxygen is essential for ATP generation through oxidative phosphorylation, and therefore must be reliably delivered to all metabolically active cells in the body. In the setting of hypoxia or low blood oxygen levels, irreversible tissue damage can rapidly occur. Hypoxia can result from an impaired oxygen-carrying capacity of the blood (e.g., anemia), impaired unloading of oxygen from hemoglobin in target tissues (e.g., carbon monoxide toxicity), or from a restriction of blood supply. Blood becomes typically saturated with oxygen after passing through the lungs, which have a vast surface area and a thin epithelial layer that allows for the rapid diffusion of gasses between blood and the environment. Oxygenated blood returns to the heart and is distributed throughout the body by way of the systemic vasculature.

Oxygen is carried in the blood in two forms. The vast majority of oxygen in the blood is bound to hemoglobin within red blood cells, while a small amount of oxygen is physically dissolved in the plasma. The regulation of unloading of oxygen from hemoglobin at target tissues is controlled by several factors, including oxygen concentration gradient, temperature, pH, and concentration of the compound 2,3-Bisphosphoglycerate. The most critical measures of adequate oxygen transportation are hemoglobin concentration and oxygen saturation; the latter is often measured clinically using pulse oximetry.

Understanding oxygen transport informs our understanding of the underlying mechanisms of tissue hypoxia, ischemia, cyanosis, and necrosis and management to improve global hypoxemia.

Conflict of interest statement

Disclosure: Carl Rhodes declares no relevant financial relationships with ineligible companies.

Disclosure: Deanna Denault declares no relevant financial relationships with ineligible companies.

Disclosure: Matthew Varacallo declares no relevant financial relationships with ineligible companies.

Copyright © 2024, StatPearls Publishing LLC.

References

    1. Chaudhry R, Varacallo M. StatPearls [Internet] StatPearls Publishing; Treasure Island (FL): 2023. Aug 8, Biochemistry, Glycolysis.
    1. Naifeh J, Dimri M, Varacallo M. StatPearls [Internet] StatPearls Publishing; Treasure Island (FL): 2023. Apr 9, Biochemistry, Aerobic Glycolysis.
    1. Amador C, Weber C, Varacallo M. StatPearls [Internet] StatPearls Publishing; Treasure Island (FL): 2023. Aug 8, Anatomy, Thorax, Bronchial.
    1. Sharma S, Hashmi MF. StatPearls [Internet] StatPearls Publishing; Treasure Island (FL): 2022. Dec 22, Partial Pressure Of Oxygen.
    1. Jelkmann W. Regulation of erythropoietin production. J Physiol. 2011 Mar 15;589(Pt 6):1251-8.
    1. Kaufman DP, Kandle PF, Murray IV, Dhamoon AS. StatPearls [Internet] StatPearls Publishing; Treasure Island (FL): 2023. Jul 31, Physiology, Oxyhemoglobin Dissociation Curve.
    1. Marengo-Rowe AJ. Structure-function relations of human hemoglobins. Proc (Bayl Univ Med Cent) 2006 Jul;19(3):239-45.
    1. Powers KA, Dhamoon AS. StatPearls [Internet] StatPearls Publishing; Treasure Island (FL): 2023. Jan 23, Physiology, Pulmonary Ventilation and Perfusion.
    1. Rizvi A, Macedo P, Babawale L, Tighe HC, Hughes JMB, Jackson JE, Shovlin CL. Hemoglobin Is a Vital Determinant of Arterial Oxygen Content in Hypoxemic Patients with Pulmonary Arteriovenous Malformations. Ann Am Thorac Soc. 2017 Jun;14(6):903-911.
    1. Torp KD, Modi P, Pollard EJ, Simon LV. StatPearls [Internet] StatPearls Publishing; Treasure Island (FL): 2023. Jul 30, Pulse Oximetry.
    1. Forget BG, Bunn HF. Classification of the disorders of hemoglobin. Cold Spring Harb Perspect Med. 2013 Feb 01;3(2):a011684.

Source: PubMed

Sponsors and Collaborators

Medical Conditions

Drug Interventions

3
Subscribe