A. ACTIVITY
Briefly explain the main cause or mechanism of the increase in respiratory rate or depth and/or respiratory difficulties in the following cases: (one to two sentences only)
1) Initiation of exercise: As the body prepares for the exercise, the rate and depth of breathing increase due to the increase of muscle cell respiration during physical activity.
2) Moderate exercise: Our body utilizes more oxygen and makes more carbon dioxide than normal when we execute moderate exercises since more ATP is needed to sustain the energy of the muscles in our body. The higher the intensity and the duration of the workout, the higher the metabolic needs of our body, which is compensated through increased pulmonary ventilation.
3) Asthma attack: During an asthma attack, the muscles in the airways tighten, and the linings on the insides swell, which gets clogged with thick mucus. Because of this, the in-and-out of air sacs is tougher; thus, more air gets stuck inside the lungs.
4) Abrupt ascent into high altitudes: During abrupt ascent into high altitudes, ventilation increases the tidal volume up to 3500 m. Additionally, the breathing rate heightens and hyperventilation may also happen to achieve an efficient amount of oxygen.
5) Pneumonia: Pneumonia is a kind of infection in the lungs, causing inflammation which leads to the filling up of fluid/pus in the air sacs of the lungs. If the build-up of fluid worsens, the lungs may unable to put oxygen into the lungs and remove the Carbon Dioxide at a precise level, leading to respiratory failure.
6) Paralysis of the phrenic nerve: As the phrenic nerve controls the contraction and expansion of the diaphragm (which allows the inhalation and exhalation of air), paralysis of the said nerve leads to the reduction of breathing capabilities or becoming unable to control voluntary breathing. Moreover, it also causes difficulty in the maintenance of gas exchange.
7) Severe tuberculosis with resulting lung scar tissue: This infection causes the reduction of surface area for gas exchange. In addition, individuals who experience this infection may have permanently impaired diffusion and ventilation mismatch, which may lead to hypoxaemic respiratory failure.
8) Severe anemia: Anemia results from the lack of Red Blood Cells or hemoglobin in the blood; thus, there is an increase in the ventilatory requirement and an increase in the work of breathing.
9) advanced COPD (chronic obstructive pulmonary disease): lung diseases such as COPD increases the risk of hypoxia, which is a state where oxygen is insufficient to support tissue levels to maintain homeostasis.
10) Advanced pregnancy: The Functional Respiratory Capacity (FRC) decreases during this period as a consequence of the increased pressure from the gravid abdomen. Furthermore, the minute ventilation also increases due to the increased oxygen consumption and carbon dioxide production, as well as the presence of progesterone that directly arouses the central respiratory center.