-
Initiation of exercise
-
-
The proprioceptors, or feeling of self movement, transmit impulses to the inspiratory portion of the medulla, increasing the pace and depth of breathing. Another is that higher motor neurons in the primary motor cortex transmit stimulatory signals to the inspiratory region, increasing both the rate and depth of breathing.
-
-
Moderate exercise
-
-
As the exercise progresses, the difference between PO2 and the number of capillaries near the alveoli becomes larger which results in a faster rate of diffusion. The faster diffusion of O2 in the blood is necessary to become metabolically active cells, these use more O2 for ATP production, hence, more increase rate in breathing.
-
-
Abrupt ascent into high altitudes
-
-
The total atmospheric pressure and the PO2 decreases as the altitude rises, it can be from 159mmHg (sea level) up to 73mmHg (10,000 to 20,000 feet high). The inhaled air decreases along with the alveolar PO2, and at last, the O2 diffuses into blood more slowly.
-
-
Paralysis of phrenic nerve
-
-
The phrenic nerve is critical to humans as it controls the diaphragm and sends signals in order for the diaphragm to contract. However, a paralyzed diaphragm can cause the lungs to weaken, have shortness of breath, can also cause recurrent pneumonia, and sleep apnea.
-
-
Severe anemia
-
-
The hemoglobin in RBCs serves as the oxygen binding sites required for respiration, hence the amount of oxygen relies on the number of RBCs and the hemoglobin they contain. Severe anemia can produce hyperventilation owing to the body's demand for additional oxygen, as well as a fast pulse or heartbeat to replenish the body's oxygen supply.
-
-
Advanced pregnancy
-
-
The advanced pregnancy inhibits the diaphragm from descending, thus, the amount of oxygen accessible is reduced, and the adaptations of the body are controlled by the progesterone. The larger uterus that occurs later in pregnancy puts pressure on the diaphragm throughout pregnancy, increasing resting oxygen consumption and the energy required for breathing.
-
Reference:
Grünebaum, A. (2021, May 20). Physical symptoms and body changes during pregnancy. babyMed.com. https://www.babymed.com/pregnancy/all-physical-pregnancy-symptoms
Lepage, R. (n.d.). Anemia disrupts respiratory system activity. Biron. https://www.biron.com/en/education-center/specialist-advice/anemia-breathing/
Phrenic nerve: Anatomy & Function. Cleveland Clinic. (2022). https://my.clevelandclinic.org/health/body/22270-phrenic-nerve
Tortora, G. J., & Derrickson, B. (2017). Principles of Anatomy and Physiology (15th ed.). Wiley.