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
- At the start of an exercise, the respiratory center can already begin regulation through proprioceptors, which monitor the movement of joints and muscles. With this, the nerve impulses from the proprioceptors would stimulate the inspiratory area of the medulla oblongata and cause a rapid increase in ventilation, followed by a more gradual increase as exercise goes on (Tortora & Derrickson, 2018).
2. Moderate exercise
- Moderate exercise exhibits a more gradual increase due to the increase in the depth of ventilation. This is because of the chemical and physical changes in the bloodstream, which include a slight decrease in the partial pressure of oxygen (PO2) due to increased oxygen consumption; a slight increase in the partial pressure of carbon dioxide because of increased production by contracting muscle fibers; and an increase in temperature, which is a result of the liberation of more heat as more oxygen is utilized (Tortora & Derrickson, 2018).
3. Asthma attack
- Asthma is often described by chronic airway inflammation, airway hypersensitivity to different stimuli, and airway obstruction. Here, the airway obstructions can be caused by smooth muscle spasms in the walls of smaller bronchi and bronchioles, edema of the mucosa of the airways, increased mucus secretion, and/or damage to the epithelium of the airway (Tortora & Derrickson, 2018).
4. Abrupt ascent into high altitudes
- High altitudes can cause a decrease in PO2in the arterial blood. The central and peripheral chemoreceptors, then, detect this decrease in PO2, which sends nerve impulses to the inspiratory area so that it can become more active and cause an increase in the rate and depth of breathing (Tortora & Derrickson, 2018).
5. Pneumonia
- When particular microbes invade the lungs of vulnerable individuals, they release toxins, which can stimulate inflammation and certain immune responses that would have harmful side effects. To be specific, the inflammation and edema would then cause the alveoli to fill with fluid, disrupting ventilation and gas exchange (Tortora & Derrickson, 2018).
6. Paralysis of phrenic nerve
- The phrenic nerve innervates the diaphragm, which is the most important muscle for inhalation (Tortora & Derrickson, 2018). Thus, the ability to exchange air may be compromised when the phrenic nerve is paralyzed (Cleveland Clinic, n.d.).
7. Severe tuberculosis with resulting lung scar tissue
- Lungs and the chest walls normally expand easily because of elastic fibers in lung tissue that can be easily stretched and surfactants in the alveolar fluid that reduce surface tension. Having scar tissue in the lungs due to tuberculosis can compromise this ability, ultimately leading to restricted breathing (Tortora & Derrickson, 2018).
8. Severe anemia
- Having severe anemia means that you have a significantly abnormally-low count of healthy red blood cells. This means that there is a substantial reduction of oxygen transport to cells, which can result in the lungs overcompensating, causing considerable breathing difficulties (National Heart, Lung, and Blood Institute, 2022).
9. Advanced COPD (chronic obstructive pulmonary disease)
- Advanced COPD would generally mean that the chronic and recurrent obstruction of airflow and increased airway resistance being experienced is poorly responding to treatment and is continually getting worse over time (Zhou et al., 2015). The obstructed airways here are usually because of pollutants like smoke, occupational exposure to dust and gases, pulmonary infections, or genetic factors (Tortora & Derrickson, 2018).
10. Advanced pregnancy
- During pregnancy, there is a substantial physiological alteration of the hormonal patterns, which would mainly affect pulmonary function, ventilatory pattern, and gas exchange (LoMauro & Aliverti, 2015). Thus, there is usually troubled breathing observed due to a decrease in lung capacities and an increase in oxygen use (Tortora & Derrickson, 2018).