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 – Heart rate is increased from a resting heart rate when exercise is initiated to supplement the energy required for the bodily activities.
2. Moderate exercise – Increased physical activity requires the lungs to increase oxygen for energy through increased breathing, and remove waste products created by the production of oxygen.
3. Asthma attack – Asthma attack occurs when the airway is inflamed, hypersensitive to a stimuli, or obstructed. Airway obstruction may be due to the smooth muscle spasms that close off the airway, increase of mucus secretion, or when epithelium damages the airways.
4. Abrupt ascent into high altitudes – High altitude environment decreases the amount of oxygen which may lead to hypoxia. The body compensates by the hyperventilation of lungs, or rapid breathing, to achieve an adequate amount of oxygen supply in the body.
5. Pneumonia – an inflammation of the alveoli caused by the toxins and immune response to certain microbes. Ventilation and gas exchange is obstructed when the alveoli accumulate excessive fluid.
6. Paralysis of phrenic nerve – Once phrenic nerve is paralyzed, it can no longer send nerve impulse to the diaphragm, the main muscle needed for breathing, to stimulate its contraction. Paralysis of phrenic nerve will then stop the breathing.
7. Severe tuberculosis with resulting lung scar tissue – Tuberculosis, an infectious disease, inflames mainly the lungs, which can be scarred and thickened. Scarred lung tissue makes it hard for the alveoli to oxygenate the rest of the body, respiratory difficulties include dry cough and shortness of breath.
8. Severe anemia – Anemia, or iron deficiency, means a low level of hemoglobin, which prevents the blood to carry enough oxygen for the body. Severe anemia increases the risk of developing complications such as an abnormal fast heartbeat (tachycardia) or heart failure.
9. Advanced COPD (chronic obstructive pulmonary disease) – a respiratory disease characterized by airflow blockage and increased airway resistance. People with COPD have swollen airways and increased mucus production which can potentially clog the airways, making it difficult to breathe.
10. Advanced pregnancy – Inside the body of a pregnant woman is the womb or uterus expansion to give way for the growing fetus that results in pressure against the diaphragm. This disables the diaphragm to fully contract, making it harder for a pregnant woman to breathe properly.