Respiratory Volumes

Que. 1 reason why a person with developing emphysema is not short of breath while resting, but becomes short of breath after climbing a flight of stairs

Emphysema is a respiratory disease that makes the respiratory units (alveoli) to stretch out of shape, making them lose their natural elasticity. This loss of elasticity hinders the lungs from emptying the unwanted air, which in the long run results in an increase of residue volume of air that cannot be exhaled out of the lungs. However, a person who has a developing emphysema rarely experience short of breath while resting, since fewer amounts of air is trapped in the lungs. Nevertheless, after an exercise, high amounts of air are trapped in the lungs, leaving less volume to accommodate the inhaled air, and this makes a person become short of breath (Balch 387).

Que. 2 Reason why tidal volume (TV) plateaus is at 60% of vital capacity (VC) while minute ventilation continues to increase during a strenuous exercise

Tidal volume is the volume of air that healthy individuals inhale during resting time while Minute ventilation is the volume of air that a person inhales during resting time in a minute. Moreover, minute ventilation is determined by both tidal volume and breathing rate. During relatively low exercise intensities, minute ventilation increases due to the increase of both tidal volume and the rate of breathing. However, during strenuous exercises, tidal volume reaches its peak level (60% of Vital capacity). At this point, the body increases the rates of breathing (35-45 times per minute), and this makes the minute ventilation to continue increasing even when tidal volume reaches a plateau (Fred 2011).

Que. 3 The importance of the change in minute ventilation with exercise

The continuous increase of minute ventilation during exercise helps the body to meet the high demand of oxygen that is required by muscles. Therefore, increase of minute ventilation increases the supply of oxygen in the body, which in the long run prevents the development of fatigue, which develops when the muscles undergo anaerobic respiration (Fred 2011).

Que. 4 Muscles that are involved in increasing the depth of respiration and an explanation of how muscle contraction causes this increase

Two muscles contribute the increase of the depth of respiration; the diaphragm and the intercostals muscles. During inhalation, the diaphragm (the muscle that separates the abdominal and the thoracic cavities) contracts and moves downward, creating a doom shaped structure, and this provides more room for the lungs to expand. On the other hand, the internal intercostals muscles contracts and pulls the rib cage both upwards and outwards, and this enlarges the chest cavity (Despopoulos, Agamemnon & Stefan 108).

Que. 5 An explanation of why Total Lung Capacity (TLC) does not change with exercise

Total lung capacity is the maximum volume of air that can be accommodated by human lung lungs (approximately 6,000 ml). This includes the sum total of tidal volume, inspiratory reserve volume, expiratory reserve volume, and residual volume. However, this amount is not affected by an exercise since the size of the lungs cannot increase (Jeremy 2005).

Que. 6 An explanation of why vital capacity does not change with exercise

Vital capacity is the total volume of air that can be exhaled after full inhalation. It involves the sum total of tidal volume, inspiratory reserve volume, and expiratory reserve volume. Moreover, this volume is approximately 80% of the total lung capacity. However, vital capacity does not change with exercise since it depends on the total lung capacity, which cannot also be altered by an exercise (vital capacity does not change since the anatomy of a person does not change prior to, or after an exercise) (Jeremy 2005).

Que. 7 An explanation of why functional residual capacity changes with exercise

Functional residual capacity is the volume of air that remains in the lungs after a normal expiration (the sum total of residual volume and expiratory reserve volume). This volume increases with exercise since an exercise increases the respiratory rate, which leads to limited time for exhalation to take place, making more air to remain in the lungs (Jeremy 2005).

Work cited

Balch, Phyllis A. Prescription for Nutritional Healing. New York: Avery, 2006. Print.

Despopoulos, Agamemnon, and Stefan Silbernagl: Color Atlas of Physiology. Stuttgart [etc.: Thieme, 2003. Print.

Fred DiMenna: How Does Exercise Affect Breathing? Published on March 13, 2011. Retrieved from, http://www.livestrong.com/article/402142-how-does-exercise-affect-breathing/

Jeremy Barnes: If A Person’s Lung Size Cannot Increase, How Does Exercise Serve To Improve Lung Function? Published on May 16, 2005. Retrieved from, http://www.scientificamerican.com/article/if-a-persons-lung-size-ca/