Analysis of Respiratory Physiology - Lab Report Example

 Analysis of Respiratory Physiology Abstract The respiratory physiology has an important role in human life. Its study therefore is very important. In light of this significance three experiments which are discussed in this report were conducted in order to assess the factors which affect the respiratory rate and interpret the findings and compare them. Vital capacity of male and female was compared and the effect of partial pressure of carbon dioxide in the inspired air along with the effect of hyperventilation on breath holding limit was also measured. Carbon dioxide is one of those factors whose presence in the inspired air directly relates to the respiratory rate and tidal volume. Along with carbon dioxide there are other various factors which control the respiratory function, of which some are controllable while others are not. Keywords: Respiratory Physiology, vital capacity, carbon dioxide, respiratory rate, hyperventilation Respiratory Physiology The necessity of breathing is well established in science. The significance of this act is well known to all. Without it any person is unable to live. This underlines the importance of the study of the respiratory physiology. Every medical professional, whether he is involved in internal medicine, surgery or even psychiatry has to have the basics of respiratory physiology. From the basic concept of gas exchange and its movement into the blood to the complex aerobic metabolism in the mitochondria and the excretion of the metabolic by-products, all of these hold an importance for a physician providing clinical care to patients. Respiratory physiology revolves around the respiratory system mainly, especially the lungs and bronchus. However without the support of musculoskeletal and nervous system lungs are unable to carry their function. The control of this process depends on a variety of factors which are spread out across different specialties (Schwartzstein & Parker, 2005). Different authors have reported different factors in different books and research articles. As Guyton and Hall, (2010) explain in their book that the different factors regulate each and every step of breathing which in turn are further regulated by the higher centers. Neural and chemical control is the highlight of this control. Breathing rate itself depends on the partial pressure of oxygen and carbon dioxide. Along with this the rate at which the alveolar air is removed from the lungs also affects the rate of breathing. On the other hand separate factors affect the diffusion of gas across respiratory membrane. These factors include the thickness and the surface area of the membrane and the diffusion coefficient of the gas. Among these factors there are some factors which can be controlled. However some factors are fixed and variability isn’t possible. Secondly the measurement of lung volume is also very significant. The lung volume has different components which need to be addressed. Inspiratory reserve volume (IRV), expiratory reserve volume (ERV), tidal volume (TV), residual volume (RV), inspiratory vital capacity (ITC), functional residual capacity (FRC), inspiratory capacity (IC) and total lung capacity (TLC) are the different static lung volumes (shown in figure -1). Their main use lies in the detection, characterization and quantification of the severity of any respiratory disease (Wanger et al., 2005). They also play an important part in the assessment of the prognosis and treatment of a respiratory disorder. TV = 0.644 L IRV = 1.615 L ERV = 1.079 L IC = 2.259 L FRC = 2.279 L VC = 3.338 L TLC = 4.538 L Figure – 1: Subdivisions of static lung capacity This lab report comprises of three different experiments, all done with the intention of investigating about respiratory physiology. The aim of the study revolves around the quest of finding about different factors which regulate breathing, their respective effects and their significance. The experiment was also designed in order to find out and compare the male and female lung volumes and interpret their significance. Results Three experiments were conducted to investigate the above aims and objective. The first experiment was conducted to find out the vital capacities of male and female and compare it. The result showed that men generally have a vital capacity of around 4.9 liters whereas females have a vital capacity around 3.3 liters. This is depicted in the below chart. Experiment 1 The second and the third experiment were both conducted to investigate and interpret the effects of different factors on the rate of breathing. Experiment 2 was assessed on the basis of the respiration rate and tidal volume while experiment 3 was assessed on the breath holding time. Both the experiments had a control sample. The results are depicted in the charts below. Experiment 2 showed an increase in both respiratory rate and tidal volume from 15 to 17 breaths/min and 0.9 to 1.4 liters respectively after re breathing expired air. Experiment 3 also showed an increase in breatg holding time under the effects of hyperventilation as the value increased from 73 to 119 seconds. Experiment 2 Experiment 3 Discussion This lab report discusses the reasons behind the increase in vital capacity of a male than a female. It further discusses the effect of two major factors which affect respiratory rate; concentration of Carbon dioxide in the air which we inspire and secondly the effect of hyperventilation. The reason behind the greater vital capacity for males lies in the fact that bodies of male have a different proportion of muscle and fat than females. Males have higher proportion of muscle and a lower proportion of fat. As muscles are supposed to require greater energy than fat this will result in an increase in lung size for males leading to a higher vital capacity. As mentioned earlier in the introduction, the partial pressure of the gases inspired plays a great role in the respiratory rate. This fact is exhibited in experiment 2 as the bag which has breathed in the expired air shows a higher tidal volume and respiratory rate. As expired air contains a higher percentage of carbon dioxide than normal inspired air this directly affects the respiratory rate. Also tidal volume is a marker of effective pulmonary ventilation (Slutsky et al., 1981). Thus when an increase percentage of carbon dioxide is breathed in both the tidal volume and respiratory rate report an increase in the values. It is a well known fact that controlled hyperventilation increases the breath holding time as is also showed by experiment 3. This is because while hyperventilating the brain perceives a message that an increase in carbon dioxide is reported. Due to this dilation of blood vessels and resulting in more oxygen consumption and greater breath holding time. Also in a controlled lab environment the air in which the person is hyperventilating will have an even greater partial pressure of oxygen than the normal inspired air. This will cause the oxygen saturation level to rise and the person will be able to hold breath for a long time. References Guyton, A. C. & Hall, J. E. (2010). Guyton and Hall textbook of medical physiology. Philadeplhia: Saunders. Schwartzstein, R. M. & Parker, M. J. (2005). Respiratory physiology: A clinical approach. Philadelphia:  Lippincott Williams & Wilkins . Slutsky, A. S., Kamm, R. D., Rossing, T. H., Loring, S. H., Lehr, J., Shapiro, A. H., Ingram, R. H. & Drazen, J. M. (1981). Effects of frequency, tidal colume and lung volume on carbon dioxide elimination in dogs by high frequency (2-30 Hz), low tidal volume ventilation, The Journal of Clinical Investigation, 68(6), 1475-1484. Wanger, J., Clausen, J. L., Coates, A., Pedersen, O. F., Brusasco, V., Burgos, F., Casaburi, R., Crapo, R., Enright, P., van der Grinten, C. P. M., Gustafsson, P., Hankinson, J., Jensen, R., Johnson, D., MacIntyre, N., McKay, R., Miller, M. R., Navajas, D., Pellegrino R. & Viegi, G. (2005). Standardization of the measurement of lung volumes. European Respiratory Journal, 26, 319-338. Read More