POST-LECTURE ACTIVITY: RESPIRATORY SYSTEM

SEE, NSM_Post-Lecture Activity: Respiratory System

SEE, NSM_Post-Lecture Activity: Respiratory System

by Nixie Skyler See -
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Briefly explain the main cause of the mechanism of increase in respiratory rate or depth and/or respiratory difficulties in the following cases (1-2 sentences only):

  1. Initiation of exercise

    • The sudden increase in the respiratory rate at the onset of exercise is attributed to the neural changes that send excitatory signals to the dorsal respiratory group (DRG) of the medullary respiratory center. These neural changes include (1) anticipation of the activity, which stimulates the limbic system; (2) sensory impulse from proprioceptors in muscles, tendons, and joints; and (3) motor impulses from the primary motor cortex (precentral gyrus). 

  1. Moderate exercise

    • A more gradual increase in breathing is manifested during moderate exercise. This is due to the physical and chemical changes in the bloodstream, including (1) slightly decreased Po2, due to increased O2 consumption; (2) slightly increased Pco2, due to increased CO2 production by contracting muscle fibers; and (3) increased temperature, due to liberation of more heat as more O2 is used. 

  1. Abrupt ascent into high altitudes

    • Hyperventilation or rapid breathing is a Hypoxic Ventilatory Response (HVR) that occurs in an abrupt ascent into high altitudes due to the detection of peripheral chemoreceptors in a decrease in arterial Po2, which increases the respiratory rate to compensate for low O2 concentration. 

  1. Paralysis of phrenic nerve

    • The phrenic nerve, as the nerve that provides the primary motor supply to the diaphragm, causes an elevation in the diaphragm when paralyzed. As a result, the expansion of the lungs becomes restrictive and reduces the forced vital capacity (FVC) by 30% of the standard value, which may increase up to 75% if the diaphragm paralysis is bilateral; hence, the increase in respiratory rate.  

  1. Severe anemia

    • Severe anemia poses a decreased level of hemoglobin as compared to normal levels, which results in a reduced capacity for blood to provide organs with oxygen. Consequently, the respiratory rate increases to allow the body to compensate for the low oxygen levels. 

  1. Advanced pregnancy

    • Two of the main causes of increased respiratory rate/depth in advanced pregnancy are (1) the growing uterus as it presses the diaphragm as the fetus grows inside the uterus; and (2) the production of progesterone (a respiratory stimulant) during pregnancy, which increases throughout pregnancy, making breathing faster. Another factor to consider that causes increased respiratory rate and/or respiratory difficulties in advanced pregnancy are the age-related changes in respiratory function— such as decreased lung elasticity, reduced chest wall compliance, and decreased respiratory muscle strength— which can lead to decreased lung capacity and an increase in respiratory infections (e.g. Pneumonia).

References:

Anaemia. (n.d.). Better Health Channel. Retrieved October 25, 2023, from https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/anaemia

Burton, D. A., Stokes, K., & Hall, G. (2004). Physiological effects of exercise. Continuing Education in Anaesthesia Critical Care & Pain, 4(6), 185–188. https://doi.org/10.1093/bjaceaccp/mkh050

Martin, P. (n.d.). Geriatric Nursing 10 Care Plans (Older Adult). Nurseslabs. Retrieved October 25, 2023, from https://nurseslabs.com/geriatric-nursing-care-plans/#h-nursing-care-plans-and-management

Nall, R. (n.d.). Causes of shortness of breath during pregnancy. Medical News Today. Retrieved October 25, 2023, from https://www.medicalnewstoday.com/articles/322316#causes

Patel, P., & Bechmann, S. (2023). Elevated Hemidiaphragm. In PubMed. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK559255/#:~:text=An%20elevated%20hemidiaphragm%20will%20show

Reed, J. C. (2019). Chest Radiology (Seventh Edition): Patterns and Differential Diagnoses. In ScienceDirect (Seventh Edition, pp. 63–70). Elsevier. https://www.sciencedirect.com/science/article/abs/pii/B9780323498319000063

San, T., Polat, S., Cingi, C., Eskiizmir, G., Oghan, F., & Cakir, B. (2013). Effects of High Altitude on Sleep and Respiratory System and Theirs Adaptations. The Scientific World Journal, 2013, 1–7. https://doi.org/10.1155/2013/241569

Tortora, G. J., & Derrickson, B. H. (2017). Tortora’s Principles of Anatomy & Physiology. Wiley.