Post-Lecture Activity: Respiratory System
1. Initiation of exercise
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Any exercise may begin with the mobilization and movement of muscles that require more oxygen to contract. This increases the depth and rate of breathing, allowing more oxygen into the lungs while omitting carbon dioxide.
2. Moderate exercise
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When exercising at a moderate intensity, metabolic demands increase together with lung volume receptors and other respiratory control center receptors, leading to a higher ventilation rate. This results in increased alveolar ventilation and gas exchange rate in the body.
3. Abrupt ascent into high altitudes
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As altitude increases, total atmospheric pressure and partial pressure of oxygen (pO2) decrease, resulting in breathing instability, alternating between periods of deep and rapid breathing, and central apnea. The primary mechanism for this hyperventilation is hypoxic stimulation of peripheral chemoreceptors.
4. Paralysis of phrenic nerve
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Since the role of the phrenic nerve is to provide the primary motor supply or movement to the diaphragm, its paralysis may cause diaphragmatic paralysis or dysfunction.
5. Severe anemia
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When the number of red blood cells is reduced, as in anemia, the blood is unable to carry a sufficient quantity of oxygen. As a result of their systems' constant attempts to restore normal oxygen levels, people with severe anemia experience hyperventilation and a rapid heart rate.
6. Advanced pregnancy
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The main cause of ventilatory changes in respiratory function during pregnancy is the physiological alteration of hormonal patterns wherein respiratory resistance rises while respiratory conductance falls. Another consideration is that the fetus tends to compress the mother's diaphragm, reducing lung volume which calls for increased airflow to ensure optimal oxygen levels.
References:
Braunstein, E. M. (2023, October 13). Anemia of chronic disease. MSD Manual Consumer Version. https://www.msdmanuals.com/home/blood-disorders/anemia/anemia-of-chronic-disease
LoMauro, A., & Aliverti, A. (2015). Respiratory physiology of pregnancy. Breathe, 11(4), 297–301. https://doi.org/10.1183/20734735.008615
Tortora, G. J., & Derrickson, B. H. (2018). Principles of anatomy and physiology. John Wiley & Sons.
West, J. B. (1982). Respiratory and circulatory control at high altitudes. The Journal of Experimental Biology, 100(1), 147–157. https://doi.org/10.1242/jeb.100.1.147
Your lungs and exercise. (2016). Breathe, 12(1), 97–100. https://doi.org/10.1183/20734735.elf121