Measuring Respiratory Volumes and Capacities

Respiratory volumes and capacities are vital for a body to function efficiently. Respiratory volume relates to the amount of air the lungs are capable of storing. Lung capacities consist of two or more sizes; These respiratory volumes include inspiratory reserve volume (IRV), tidal volume (TV), vital size (VC), and expiratory reserve volume (ERV). The average adult is estimated to have a 6-liter lung capacity, although it is impossible for lungs to operate at the optimal position. The lung capacity of a human is relatively low compared to many animals such as a cheetah, where their lung capacity is higher to allow for higher air flow that increases the oxygen levels in the blood which, in turn, allows blood to flow to the muscles quicker. In this experiment, we will assess how sex, age, and height influences or impedes respiratory volumes.

Tidal volume is the amount of air inhaled and exhaled. In this experiment, one inhaled calmly as if they were generally breathing without thought and emitted in a device called a spirometer to measure the amount of air expelled in a normal respiratory cycle. Tidal volume in a normal respiratory cycle in an average adult is estimated to be one-half of a liter. Expiratory reserve volume, on the other hand, refers to the additional amount of air that can be exhaled after the tidal volume exhalation.

In other words, one emits in a relaxed state and forcibly ejects further immediately after the initial expiration. Vital capacity is the total amount of air that moves in and out of the lungs. In other words, one bends over and fully exhales, then stand up straight and inhales as much air as possible before forcibly exhaling fully. Inspiratory reserve volume is the additional volume of air inhaled after the tidal volume inhalation. I other words, one breath in a relaxed state and then takes a forced puff of air immediately after the initial inhalation. While a spirometer used in this experiment cannot measure inspiratory reserve volume, you can calculate this by adding together the values of tidal volume, vital capacity, and expiratory reserve volume together.

This experiment was performed on 113 test subjects of varying age, height, and sex, over a period of several years. The data measuring respiratory volumes and capacities considered age, height, and reproduction of 113 subjects. Using a meter stick the average height and given ages of the questions were recorded as 65.60 inches and 24.30 years respectively. Based on the collected data, it was concluded that the subjects who were under the age of 20 years had the highest average tidal volume. This can be attributed to the active lifestyles and physically demanding sporting activities that young adults typically participate in. Another factor can be the rigorous course schedules set forth by the education system that can lead to fatigue and a requirement for better blood flow that requires more oxygen. Also, younger test subjects tend to have stronger respiratory muscles supporting the respiratory cycle.

Older adults who live more reserved lifestyles would generally show significantly reduced lung functions since their peak during the ages of 20-25 years old. Reduced lung function can be attributed to exposure to a wide range of hazardous chemicals either in their work field or living environments. In this experiment, data shows that test subjects 40 years and older had the highest average expiratory reserve volume and vital capacity. The increase in expiratory reserve and essential role as one age can be attributed to the increased airspace within the lungs. As the body ages, the muscles of the rib cage and diaphragm become weaker and thinner. The rib cage muscles and bones tend to deteriorate much quicker than the diaphragm muscle which means more airspace is created at a faster rate than the diaphragm loses strength. This means that the expiratory reserve volume and vital capacity increases.

Data revealed that test subjects less than 5 feet tall had the highest average tidal volume, while test subjects over 6 feet tall had the highest average expiratory reserve volume, vital capacity, and inspiratory reserve volumes. These results show a direct relationship between lung volume and height. As height increases lung capacity increases. This result can be attributed to the fact that the taller subjects are at a slightly higher altitude and experience partial oxygen. Height also increases vital capacity, expiratory reserve volume, and inspiratory reserve volume, while tidal volume remains the same.

The data further revealed that men had higher respiratory averages in all the respiratory volumes. This can be attributed to the fact that men generally have larger lungs compared to women. Men have historically worked more physically demanding jobs than women which can explain the larger lung capacities. Larger lungs mean a greater surface area for the cells involved in the gas exchange and greater lung capacity. Men also have stronger respiratory muscles and larger airways.