Briefly explain the main cause or mechanism of increase in respiratory rate or depth and/or respiratory difficulties in the following cases: (one to two sentences only)
1. Initiation of exercise
- When starting an exercise, ATP is required in our cells causing them to undergo cellular respiration and produce more carbon dioxide (CO2). When chemoreceptors of the medulla detect lowering of blood pH level, it will then instruct the respiratory system to breathe more quickly to eliminate the CO2 consume more oxygen (O2), and preserve homeostasis.
2. Moderate exercise
- There is an increase O2 consumption and breathing because there's an increase in the depth of breathing rather than the breathing rate. This is also caused by chemical and physical changes such as decreased partial pressure of CO2 due to intake of O2 and due to increased temperature.
3. Abrupt ascent into high altitudes
- The external air pressure at high altitudes is lower than the pressure inside the lungs, causing difficulty for veins to pump O2 throughout the body and pull the thin air inside. Ventilatory adaptation to hypoxia, which is caused by prolonged exposure to high-altitude hypoxia, is characterized by an increase in breathing mediated by the carotid body (the sensory input from peripheral chemoreceptors sensitizes the central chemoreceptors).
4. Paralysis of phrenic nerve
- When the phrenic nerve is paralyzed, there can be elevation and paralysis of the diaphragm , and it can be unilateral or bilateral. Since the diaphragm assists in respiration, paralysis could cause shortness of breath (respiratory difficulties) and sleeping problems, as lungs will not be able to inhale and exhale air from outside (as diaphragm weakened).
5. Severe anemia
- Severe anemia decreases the capacity of the blood to carry oxygen and lowers the hemoglobin levels causing inadequate O2 from reaching the brain. Problems with breathing result from the lungs excessively compensating to deliver more oxygen into the body.
6. Advanced pregnancy
- Pregnancy at an advanced maternal age (above 35 years old) is thought to increase the likelihood of negative perinatal and maternal outcomes. While shortness of breath can be caused by the expansion of uterus squeezing the lungs, the high levels of progesterone (hormone that increases during pregnancy) can cause the mother to breathe faster.
REFERENCES:
- Cleveland Clinic Medical Professional . (n.d.). Phrenic nerve: Anatomy & Function. Cleveland Clinic. https://my.clevelandclinic.org/health/body/22270-phrenic-nerve
- Glick, I., Kadish, E., & Rottenstreich, M. (2021, August 10). Management of pregnancy in women of advanced maternal age: Improving outcomes for mother and baby. International journal of women’s health. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8364335/
- Prabhakar, N. R., & Semenza, G. L. (2015, September). Oxygen sensing and homeostasis. Physiology (Bethesda, Md.). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4556828/#:~:text=Chronic%20exposure%20to%20high%2Daltitude,22%2C%2026%2C%2046).
- Rojas, Y. (2020, July 23). 10 symptoms of anemia you shouldn’t ignore. Texas Medical Institute. https://www.texasmedicalinstitute.com/10-symptoms-of-anemia-you-shouldnt-ignore/#:~:text=With%20anemia%2C%20the%20lungs%20overcompensate,%2C%20neurological%20issues%2C%20and%20vertigo.
- Shortness of breath in pregnancy. Harvard Health. (n.d.). https://www.health.harvard.edu/decision_guide/shortness-of-breath-in-pregnancy#:~:text=Many%2C%20many%20women%20who%20are,they%20have%20for%20oxygen%20exchange.
- Tortora, G. J., &; Derrickson, B. (2017). Chapter 23: The Respiratory System: (23.9) Exercise and the Respiratory System. In Principles of anatomy and physiology (15th Edition, pp. 888–889). essay, Wiley Custom Learning Solutions.
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