Oxygen: Difference between revisions
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# Ventilation is the process by which air moves in and out of the lungs. | # Ventilation is the process by which air moves in and out of the lungs. | ||
# Diffusion is the spontaneous movement of gases, without the use of any energy or effort by the body, between the alveoli and the capillaries in the lungs. | # Diffusion is the spontaneous movement of gases, without the use of any energy or effort by the body, between the alveoli and the capillaries in the lungs. | ||
# Perfusion is the process by which the cardiovascular system pumps blood throughout the lungs | # Perfusion is the process by which the cardiovascular system pumps blood throughout the lungs.<ref name=":1">Oxygen review Human body Available: https://www.oxygen-review.com/human-body.html<nowiki/>(accessed 22.12.2021)</ref>.<ref name=":0">Rhodes CE, Varacallo M. [https://www.statpearls.com/articlelibrary/viewarticle/26494/ Physiology, oxygen transport.] InStatPearls [Internet] 2020 Sep 13. StatPearls Publishing. Available: https://www.statpearls.com/articlelibrary/viewarticle/26494/<nowiki/>(accessed 22.12.2021)</ref><ref name=":2">Medical daily How humans use oxygen Available: https://www.medicaldaily.com/how-oxygen-used-human-body-complex-journey-explained-415657 (accessed 23.12.2021)</ref>. | ||
== Oxygen Transport == | == Oxygen Transport == | ||
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. | 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. | ||
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* The heme group of hemoglobin binds oxygen (changing haemoglobin’s color from bluish red to bright red). | * The heme group of hemoglobin binds oxygen (changing haemoglobin’s color from bluish red to bright red). | ||
* O2 is handed-off to an enzyme (monooxygenase) that also has an active site with an atom of iron. Monooxygenases are enzymes that catalyze the insertion of a single oxygen atom from O(2) into an organic substrate.<ref name=":1" />.<ref name=":0" /><ref name=":2" />. | * O2 is handed-off to an enzyme (monooxygenase) that also has an active site with an atom of iron. Monooxygenases are enzymes that catalyze the insertion of a single oxygen atom from O(2) into an organic substrate.<ref name=":1" />.<ref name=":0" /><ref name=":2" />. | ||
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 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<ref name=":0" />. | ||
* A persistent reduction in oxygen transportation capacity is most often the result of [[Anaemia|anemia.]] | * A persistent reduction in oxygen transportation capacity is most often the result of [[Anaemia|anemia.]] | ||
Revision as of 23:49, 22 December 2021
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Introduction[edit | edit source]
Oxygen is a vital gas, responsible for life on earth. It generates energy and supports the life of all the living organisms. In order to survive, all of our cells need oxygen. Three processes are essential for the transfer of oxygen from the outside air to the blood flowing through the lungs: ventilation, diffusion, and perfusion
- Ventilation is the process by which air moves in and out of the lungs.
- Diffusion is the spontaneous movement of gases, without the use of any energy or effort by the body, between the alveoli and the capillaries in the lungs.
- Perfusion is the process by which the cardiovascular system pumps blood throughout the lungs.[1].[2][3].
Oxygen Transport[edit | edit source]
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.
- When in the lungs oxygen diffuses through membranes and into red blood cells.
- The heme group of hemoglobin binds oxygen (changing haemoglobin’s color from bluish red to bright red).
- O2 is handed-off to an enzyme (monooxygenase) that also has an active site with an atom of iron. Monooxygenases are enzymes that catalyze the insertion of a single oxygen atom from O(2) into an organic substrate.[1].[2][3].
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[2].
- A persistent reduction in oxygen transportation capacity is most often the result of anemia.
Hemoglobin (Hgb or Hb)[edit | edit source]
Hemoglobin (Hgb or Hb) is the primary carrier of oxygen in humans. Approximately 98% of total oxygen transported in the blood is bound to hemoglobin, while only 2% is dissolved directly in plasma.
- Hemoglobin is a metalloprotein with four subunits composed of an iron-containing heme group attached to a globin polypeptide chain.
- One molecule of oxygen can bind to the iron atom of a heme group, giving each hemoglobin the ability to transport four oxygen molecules.
Various defects in the synthesis or structure of erythrocytes, hemoglobin, or the globin polypeptide chain can impair the oxygen-carrying capacity of the blood and lead to hypoxia.
Molecular oxygen, O2[edit | edit source]
Molecular oxygen, O2, is essential for cellular respiration in all aerobic organisms. Oxygen is used as an electron acceptor in mitochondria to generate chemical energy. For more on cellular respiration see ATP.[1]
References[edit | edit source]
- ↑ 1.0 1.1 1.2 Oxygen review Human body Available: https://www.oxygen-review.com/human-body.html(accessed 22.12.2021)
- ↑ 2.0 2.1 2.2 Rhodes CE, Varacallo M. Physiology, oxygen transport. InStatPearls [Internet] 2020 Sep 13. StatPearls Publishing. Available: https://www.statpearls.com/articlelibrary/viewarticle/26494/(accessed 22.12.2021)
- ↑ 3.0 3.1 Medical daily How humans use oxygen Available: https://www.medicaldaily.com/how-oxygen-used-human-body-complex-journey-explained-415657 (accessed 23.12.2021)
