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 we start exercising, the movement of the body (input), especially that of the muscles and joints, will be detected by proprioceptors. These will then send impulses to the medulla oblongata to stimulate the inspiratory area, which in turn increases the respiratory rate and depth of breathing.
2. Moderate exercise: As we continue exercising, the mechanisms of the proprioceptors and medulla oblongata continue to trigger increased respiratory rate and depth of breathing. By extension, prolonged and/or intensified movement causes a rise in the body’s carbon dioxide levels; this stimulates the inspiratory center to increase the rate and depth of breathing.
3. Abrupt ascent into high altitudes: High altitudes can cause a significant drop in the body’s oxygen level, which may lead to hypoxia and other severe conditions. As such, the body compensates for the decrease in oxygen through the stimulation of the inspiratory center by peripheral chemoreceptors, enforcing hyperventilation (increased respiratory rate and depth of breathing).
4. Paralysis of phrenic nerve: Paralysis of the Phrenic Nerve can ultimately lead to difficulty in breathing as it controls the contraction of the diaphragm. This can interfere with the normal capacity of the lungs to take in and breathe out air.
5. Severe anemia: Anemia is characterized by the red blood cells’ inability to carry oxygen, thus decreasing the amount of oxygen in the body. As a result, increased respiratory rate or hyperventilation is enforced to compensate for the lowered amount of oxygen.
10. Advanced pregnancy: In advanced pregnancy, the diaphragm of the mother is subjected to enhanced pressure due to the space occupied by the baby, hence an increase in the respiratory rate and depth of breathing occurs. Moreover, higher hormonal levels, most especially that of progesterone, is accommodated by increasing the mother’s depth of breathing.