1. Initiation of exercise
Proprioceptors influence respiratory rate and depth during exercise initiation by detecting muscle length, tension, and joint angle changes, enabling the medulla oblongata to anticipate oxygen demand. Increasing CO2 levels at exercise onset stimulate chemoreceptors, triggering the medullary rhythmicity area.
2. Moderate exercise
The mechanism in this case is similar with case # 1. However, the demand for oxygen and production of carbon dioxide are more elevated than case #1
3. Abrupt ascent into high altitudes
At high altitudes, reduced presence and pressure of oxygen stimulates our peripheral chemoreceptors. This makes us hyperventilate or increase in respiratory rate and depth to compensate for lower oxygen availability, ensuring adequate oxygen saturation.
4. Paralysis of phrenic nerve
Phrenic nerve paralysis impairs diaphragmatic movement, which leads to shallow breathing, reduced lung expansion, and decreased oxygen exchange.
5. Severe anemia
Anemia reduces oxygen-carrying capacity of the RBC, triggering peripheral chemoreceptors. As such, it prompts an increase in respiratory rate and depth to compensate and to ensure sufficient oxygenation.
6. Advanced pregnancy
There is an increased respiratory rate and depth to accommodate the oxygen demand of both the mother and the developing fetus, as well as of the increased progesterone. Moreover, the developing fetus occupies space and compresses the mother’s diaphragm, thus restricting its movement and further influencing her breathing patterns.