Q1. Describe the mechanics of inspiration and expiration in a resting person
Breathing also referred to as ventilation is involved with the air movement into and out of the lungs to the atmosphere. The breathing process comprises two phases, which are inspiration and expiration. West (2014) indicated that the main muscles that are involved in the breathing movements are the diaphragm which forms the chest cavity floor, the intercostals muscles that are attached to the ribs. During the process of inspiration, the external intercostals muscles and diaphragm contract allowing the air to flow in. Petechuk (2010) indicated that the diaphragm moves down during inspiration and this increases the volume of the chest (thoracic) cavity. On the other hand, the external intercostals muscles pull the ribs outward and upwards. This expands the rib cage and further increase the chest volume. According to Ionescu (2013), the increase in the chest volume lowered the lungs the air pressure as compared to the atmospheric air. However, because the air always flows from a high-pressure region to an area of low pressure, the air will travel through the conducting airways of the body into the alveoli in the lungs. The conducting airways of the body include the nostrils, the throat, larynx, and the trachea.
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Expiration in a resting person has contrasting muscular activities to the inspiration of a resting man. During the expiration of a resting man, the external intercostals muscles and the diaphragm relax. This restores the thoracic activity to its smaller (original) volume, and this forces the air out of the lungs into the atmosphere. For an adult who is healthy and is at rest, the breathing mechanism sets up a rate typically between 16 and 20 breaths in a minute.
Q2. Discuss how lung volumes change in response to vigorous breathing (forced inspiration and expiration) and what additional muscles will be used to ensure these volumes are met
During forced inspiration or expiration also known as vigorous breathing, the lung volumes change because of some additional usage of muscles. Forced breathing normally occurs when a person is engaging in a rigorous activity is exercising (Martin, 2012). It may also be described as deeper breathing and applies more musculature for expiration and inspiration.
According to Nieman & President’s Council on Physical Fitness and Sports (U.S.) (2013), when an individual is exercising, there is an increased demand for oxygen in the body and also increased ventilation of the lungs. Furthermore, the frequency for deflation and inflation increases, and the quantity of air that is breathed in and out increases too.
West (2014) indicated that during the inspiration process, the additional muscles that are attached to the sternum, and the ribs help in raising the ribcage. On the other hand, during forced expiration West (2014) asserted that the internal intercostals muscles contract and therefore pull down the rib cage more quickly. Moreover, the abdominal muscles also contract, and therefore push up on the diaphragm. This forces more air to move out of the lungs. This movement of the diaphragm, internal intercostals muscles, and abdominal muscles helps individuals to breathe more deeply and quickly. Both expiration and inspiration are active processes now that require the contraction of the muscles.
As an individual inhale, the diaphragm contracts and moves downwards before flattening out. This allows the ribs and the lungs to expand in all planes and thereby increasing the thoracic cavity volume. Similarly, Petechuk (2010) explained that the abdominal wall comprises four layers, with the transverses abdominis muscle being the deepest layer and supports the trunk. During forced exhalation, Petechuk (2010) pointed out that the traverses abdominal muscle starts to contract, and this increases the abdominal pressure
Q3. Describe any four normal age-related changes to the anatomy and physiology of the respiratory system in healthy elderly adults (over 65 years)
- Decreased strength of the respiratory muscles. The diaphragm, intercostals muscles, and abdominal muscles that help in the process of breathing will decrease and the effect is that an inadequate amount of oxygen will be inhaled. Furthermore, the amount of carbon iv oxide will be higher because of the weaker respiratory muscles to help in exhalation. The implication of the decreased strength of the respiratory muscle is that there will be reduced functional reserve of the pulmonary with no change at rest, while with exertion; it will result in decreased exercise tolerance and dyspnea (Lalley, 2013).
- The chest wall will become stiffer with reduced compliance. This will lead to decreased chest and lung expansion and respiratory excursion with less effective exhalation. Furthermore, the respiratory rate will fall to about 12 to 24 breaths in a minute. Stiffness of the chest wall maybe because of the stiffness or weakness of the respiratory muscles, the diminished strength in the chest wall, or pain associated with the age on the skeletal system. The ribs may be affected also be affected by osteoporosis and therefore make the chest wall stiff (Farley, McLafferty & Hendry, 2011).
- Decreased response to hypercapnia and hypoxia. The implication is the decreased cough, and also foreign matter/mucus clearance. Hypoxia which is the condition associated with minimal or no oxygen will result because diminished energy to enable inhalation of the aged individual. Therefore, less amount of oxygen will be supplied in the whole body (Lalley, 2013).
- Diminished macrophages and ciliary activity, hence resulting in decreased cough reflexes and drier mucus membranes. This will lead to an increased risk of bronchospasm and infection with airway obstruction (Farley, McLafferty & Hendry, 2011).
Q4. Describe three effects long term exercise has in maintaining a healthy respiratory system
- Because of the long term exercise, pulmonary ventilation will increase because of the stimulation of the respiratory centers found in the brain stem. This will help in increasing air sacs in the lungs. Furthermore, it will help in clearing out of any mucus in the respiratory system that may be in (Ionescu, 2013). Furthermore, long term exercises help in increasing the capacity of the lungs. Long-term exercises will enable the respiratory system to be healthy especially the lungs. Those will lead to the production of a greater number of the alveoli, and those will increase the tidal volume as well as the vital capacity of the lungs
- The strength of the diaphragm muscle will also be increased with long term exercises. Increased strength of the diaphragm will helpful especially in forced expiration and when an individual engages in exercises.
- Long term exercises will make the lungs to supply enough air to the body cells faster. This will make the cells to use the air in the more production of ATP. Similarly, it will help the cell in the removal of the carbon iv oxide and therefore prevent impairing of the blood (Nieman & President’s Council on Physical Fitness and Sports (U.S.), 2013).
Lalley, P.M. (2013) The aging respiratory system – Pulmonary structure, function, and neural control. Respiratory Physiology & Neurobiology 187′ 199-210′
West, J. B. (2014). Mechanics of breathing. San Diego, Calif: West ; [New York: for loan or sale by Audio Visual Medical Marketing.
Petechuk, D. (2010). The respiratory system. Westport, Conn: Greenwood Press.
Ionescu, C. M. (2013). The human respiratory system: An analysis of the interplay between anatomy, structure, breathing, and fractal dynamics. London: Springer.
Martin, D. E. (2012). Respiratory anatomy and physiology. St. Louis, Mo: Mosby.
Farley, A., McLafferty, E., & Hendry, C. (2011). The Physiological Effects of Ageing. Hoboken: John Wiley & Sons.
Nieman, D. C., & President’s Council on Physical Fitness and Sports (U.S.). (2013). Does exercise alter immune function and respiratory infections?. Washington, D.C: President’s Council on Physical Fitness and Sports.
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