Respiratory Physiology Investigations – Lab Report Example
Respiratory Physiology Investigations Respiratory physiology investigations INTRODUCTION Breathing process involves the exchange of air to the environment. The air is composed of different mixtures of gases namely Nitrogen at 78%, oxygen at 21%, carbon dioxide at 0.04% and traces of noble gas and hydrogen. Air rich in oxygen is taken in by the nostrils found in the nasal cavity. The air is kept warm because of the presence of blood capillaries (George & George, 2013). The Air enters the pharynx then passed to larynx before reaching the trachea. The presence of secretory cells and the cilia within the trachea and the bronchi moisten the passing air with the mucus and trap any foreign particle from the nostril (Schroter & Sudlow, 1969).
Lungs that are spongy, elastic organs are in pairs and help in purification of air. The structures include air sacs and the alveoli. Alveolar ducts join forming the bronchioles that connect to form up the respiratory tract. Blood vessels of pulmonary artery and vein circulate blood in the lungs. The diaphragm separates the abdominal cavity from the thorax and helps in breathing through systole and diastole processes. Trachea, also known as the windpipe is located in front of oesophagus and held in position by cartilaginous rings. The Trachea then branches into main branches of bronchi (George & George, 2013).
The air in the lung comprises of both volume and capacities. Total lung capacity is subdivided on assumption that the stable point of the respiratory cycle is in the resting position. This is because, during resting, the same amount of functional residual capacity (FRC) is exhaled out. Capacity is used when measurements are divided into other sizes of smaller entities like vital capacity (VC) (Schroter & Sudlow, 1969). The respiratory physiology investigation relates the developed practical skills and the physiological measurements of respiratory systems. The report, therefore, explains the different types of volumes obtained during exhalation after a given exercise since capacities can be measured unlike the volume quantities to calculate all the parameters.
To measure the breathing parameters of healthy subjects of the same healthy subject after exercise
To identify the relationship between the developed practical and the physiological measurements of respiratory systems
Healthy subjects with no cardiovascular problems were identified and used in the spirometer amplifier. The apparatus was then set in a proper position, and all precautions met to find out if the subject is breathing properly through the correct end of the flow head and volume channels clicked.
Five breaths were recorded for a period of about 45 seconds, and after reaching maximum inhalation volume and obtaining exhalation volume, the subject was allowed to breathe normally through the spirometer for five breath cycles.
After a period of exercise, measurements were repeated to obtain the mean and values recorded as below.
Percentage of the vital capacity was then obtained at different time intervals and recorded as follows.
Time in seconds
% of vital capacity exhaled
0.318 = 13.7%
0.646 = 27.9%
1.108 = 47.8%
2.268 = 97.9%
2.317 = 100%
Changes in the lung volumes occur in a manner that is predictable during periods of quiet and deep breathing. The percentage of vital capacity increased with increase in the time the measurement was taken after the exercise. For the first few seconds, the percentage was low because the expiratory reserve volume (ERV) was high because the rate was still fast. However, as time increased, inspiratory reserve volume (IRV) became high and thus leading to greater vital capacity. The 3.0 second was the time the body started to be at the resting position leading to the high percentage rate of VC.
At a resting position, there is a normal amount of air being inhaled and exhaled. It is the tidal volume (TD) and approximately 500 ml in volume. The mean values obtained in the experiment from the volumes recorded were not the theoretical values. This may be as a result of errors in the spirometer amplifier. Seemingly, one can take a deep breath at once and immediately blow out all the air taken in. This amount of air is the vital capacity (VC) and is approximate 3litres in amount (Rubini et al., 2011).
The vital capacity is never used throughout a given day, but the tidal volume is taken in and out. Activities like speaking, running, and any physical exercise enables a person to exhale more than inhalation than the tidal volume. The extra air obtained beyond the tidal volume is referred to as the inspiratory capacity (IC) when inhaled and expiratory capacity (EC) when exhaled (Rubini et al., 2011).
When air is exhaled even as much as possible, all the air from the respiratory tract can never be eliminated all. This can buckle the tract. The volume of the air that can never be exhaled is the residual volume (RV), and it is approximately 1.2 litres. Exhalations are normally on the tidal volume capacities. From the experiment, even after forced exhalation, volumes of the subjects were obtained and mean calculated.
In conclusion, therefore, the exhaled air plus the residual volume always remain in the tract. The combination of this air is the functional residual capacity. Total lung capacity (TLC) is the total amount of air remaining in the respiratory system together with the amount that can never be inhaled (Randles & Dabner, 2015). During the normal healthy state, breathing is expected to produce the actual volumes of air in the circulation.
Any disease affecting the lungs has an impact on the volume of air exchanged in the lungs. Alveoli can get stiffer when affected and, as a result, the lungs expand lesser leading to a reduction in air volumes and capacities. Thus, the pathophysiology like from the neuromuscular infections restricts the lung in the respiration process. Increasing rate of respiration helps in compensating for the lost volume as a result of maintaining tidal volume (Randles & Dabner, 2015).
Obstruction of the respiratory pathways as put by Rubini et al., 2011, may also affect the total lung capacities from diseases like the asthma. They lead to narrowing of the tracts leading to breathing difficulties especially when exhaling. As a result, the residual volume is increased since some air is trapped leading to increased functional residual capacity. The inspiratory reserve volume (IRV) becomes constant through the expiratory reserve volume will increase.
George H., F, & George J., H 2013, The Respiratory System, n.p.: McGraw-Hill Professional
Randles, D, & Dabner, S 2015, Physiology: Applied respiratory physiology, Anaesthesia & Intensive Care Medicine, 16, Thoracic Anaesthesia, pp. 63-67,
Rubini, A, Parmagnani, A, & Bondi, M 2011, Daily variations in lung volume measurements in young healthy adults, Biological Rhythm Research, 42, 3, pp. 261-265,
Schroter, R., & Sudlow, M. F. (1969). Flow patterns in models of the human bronchial airways. Respiration Physiology, 7(3), 341-355.