1. Initiation of exercise
-
In the initiation of exercise, there is an abrupt increase in respiratory rate and depth due to neural changes in the medulla, particularly in the dorsal respiratory group (DRG). These changes are set in motion by your body's anticipation of physical activity and the signals it receives from muscle sensors called proprioceptors.
2. Moderate exercise
-
In moderate exercise, there is also an increase in respiratory rate however, there is a notable gradual increase in this compared to the initiation of exercise. The partial pressure of oxygen decreases as a result of increased oxygen consumption by muscles, increase in partial pressure of carbon dioxide in the bloodstream, and elevated body temperature all contribute to the adjustments of respiratory rate and depth during this activity.
3. Abrupt descent into high altitudes
-
During an abrupt ascent into high altitude, there is an increase in depth and rate of respiration because there is an effort to compensate for low oxygen levels in high altitude. The body has a rapid and automatic response to increase the amount of breaths which also leads to increased depth of respiration to bring in more oxygen to the body.
4. Paralysis of phrenic nerve
-
A paralyzed phrenic nerve may cause breathing difficulties because an area of the diaphragm involved for respiration is weak or inactive. As a result, the afflicted part may cause a decrease in lung volume, affecting the ability to breathe deeply.
5. Severe anemia
-
People with severe anemia have lesser amount of red blood cells that carry oxygen to tissues therefore, they experience difficulty in breathing because the blood cannot deliver sufficient amount of oxygen that their body requires. Therefore, there is an increased rate in breathing and depth as they effort to increase the amount of oxygen in the blood.
6. Advanced pregnancy
-
During advanced pregnancy, there are notable changes in respiration as the growing fetus pushes unto the diaphragm and limits its the space available for the lungs to expand upon breathing. This results to an increase respiratory rate and difficulty in breathing as they rely on their chest muscles to breathe rather than their diaphragm. Moreso, an increase in progesterone hormone may cause the mother to breathe more deeply.