Factors Affecting the Rate of Breathing, Lab Report Example

Research Question

How do factors, such as exercise, movement, coughing, and temperature affect the rate of breathing in an individual?

Background Information

The respiratory system is comprised of a set of tubes that branch out into clusters of air sacs referred to as alveoli.  It is in the walls of the alveoli that oxygen and carbon dioxide diffuse into the bloodstream.  There are several factors that influence diffusion across the membrane, such as the surface area of the wall, the distance of diffusion, and the concentration gradient.  The lungs have a large surface area with a thin wall in order for the diffusion distance to increase.  Respiration in the human lung occurs through muscular contraction.  In an individual at rest, expiration in the lungs is passive, in which elasticity and gravity decrease the thoracic volume.  In an individual during exercise, however, the expiration is forced and the contraction is done through the intercostal muscles.  (Normal Breathing.com; iWorx)

The total amount of air that moves into and out of the lungs during a breathing cycle is referred to as the tidal volume.  It should be noted that this is not the maximum amount of air that can be moved through the lungs because the tidal volume does not include the reserve volumes of the lungs.  For instance, even if the reserve volume of air in the lungs is expelled from the lungs, there is still air left in the lungs.  In addition to the amount of air expelled during breather, the rate of breathing can also be altered.  There are two mechanisms that control respiration in the medulla of the brain in order for the exchange of oxygen and carbon dioxide to react with the body’s requirements.  It is indicated that for adults the normal rate of breathing is ranges from 12-15 breathes per minute.  The respiratory rates for individuals who are sick can range from 20-30 breaths per minute.  Therefore, there are several factors that can affect the rate of breathing, such as disease, emotion, speech, exercise, temperature and gravity.  The current experiment examines some factors that can affect the rate of breathing.  Since the tools are not available in order to test breathing directly, the individuals used in the experiment will count the number of breathes after each trial for each factor.  (Normal Breathing.com; iWorx)

Hypothesis

Breathing rates can be affected through certain factors, as mentioned previously.  It is hypothesized that the rate of breathing in an individual will increase during activities, such as exercise, increased movement, and coughing.
Variables
Independent Variable: the independent variables are exercise, coughing, and performing tasks.

Dependent Variable: The dependent variable is breathing.

Controlled Variable: The controlled variable is breathing rate at rest and time.

Apparatus

• 4 Volunteers or Subjects
• Stop Watch
• Needle and Thread
• Thermometer (basic Room Temperature thermometer)

Method

Four volunteers or subjects for the study were asked to participate in the laboratory experiment.  The volunteers were two male and two female ages 15-17.  The study was performed on each individual during the same time period on the same day.  All subjects were instructed to sit quietly and breathe normally before other instructions.  The temperature of the experiment setting was taken to ensure the initial experiment was conducted at room temperature.  Four factors were manipulated in order to test the rate of breathing in an individual.  The subjects breathing rates at rest were taken.  All factors were taken for a total of three trials per factor.  20 minute intervals between trials were completed in order for the subject to return to the rest phase.  The first factor tested breathing rates during coughing.  The subjects were instructed to begin coughing for thirty seconds and then the rate of breathing was recorded.  The rate of breathing was recorded via counting the number of breathes after each trial for each factor for 30 seconds.  The number of breathes were measured for 15 seconds and then multiplied by 4.

# of breathes = Breathes per 15 seconds * 4

The second factor tested was breathing rates while performing a task.  The subjects were instructed try and put a thread through a needle head.  Once the subject was able to place the thread through the needle head, the breathing rate was recorded.  The third factor tested was breathing rate immediately after exercise.  The subjects were instructed to walk up and down a set of stairs for thirty seconds.  The breathing rate was recorded immediately after completion.

Data Collection and Processing (Dcp)

Collected Data

The data was collected and the raw data was recorded in a table format, as illustrated in Table 1.

Table 1.  The raw data collected during the experiment for four subjects.  Two female and two male age range 15-17.  The breathing rate was measured in breathes per minute after the completion of the tasks.

Data Processing

Table 2.  Average Breathing rate (Breathes/minute) and Standard Deviation for each Subject.

Errors/Uncertainties

Table 3.  % Error for Averages. % Error based on at rest values.

Data Presentation

Conclusion and Evaluation (Ce)

Conclusion

Physiologically, it has been indicated that a body-oxygen test after a usual exhalation is a more accurate measurement than an individual’s breathing frequency; however, for this laboratory, the rate of breathing was measured using breathes per minute after the given variable was implemented.  The respiration rate at rest corresponds to the individual’s unconscious breathing and has been reported to be around 12 breathes per minute on average.   The results of the current experiment supported the hypothesis that breathing rates would increase during activities such as exercise, movement and coughing; however, the results did not support the hypothesis that breathing rates would increase during tasks or work.  The results showed an increase in breathing rates for all subjects, both female and male, during coughing and exercise; however, during the needle and thread task, the breathing rate decreased.

The results for coughing and exercise were expected since the individual was undergoing more work and using energy and muscle action in order to conduct their task; therefore, the more oxygen was used and therefore more oxygen was needed in the lungs and bloodstream.  In regard to the results for the needle and thread, it is possible that the individuals were concentrating and more relaxed during the task and therefore, the breathing rate decreased.  As seen in Table 2 and Figure 1, the highest breathing rate was observed in the exercise activity for all subjects and the lowest breathing rate was observed in the needle and thread activity.  An increase in breathing rate also increased during the coughing activity, compared to the at rest breathing rate.  (Figure 1)  The standard deviations for the averages for each subject and activity were plotted in Figure 1.  The standard deviations were below 1, indicating that the data set for each trial was accurate.  The percent errors for the trials were also calculated.  (Table 3).   The percent errors were relatively high at greater than 10% for each trial.  The percent errors were calculated based on the at rest breathing rate.  The percent errors are expected to be high since the breathing rates for each activity were expected to increase after the activity.  Further statistical analysis, such as an ANOVA could result in a comparison between resting breathing rates and variable breathing rates.

The experiment relied on the counting of the subjects after each activity; therefore, results may not be accurate.  Future experiments should use a spirometer to conduct a breathing experiment.   A spirometer can obtain the maximum inspiratory flow rates and expiratory flow rates after each variable or factor implemented in the study.   In addition, the spirometer can provide tidal volume and air expelled.  The use of this type of instrument can provide more data and offer the research a data set to use for correlational analyses.

Works Cited

Normal Breathing.com.  Normal Breathing Defeats Chronic Diseases. (2013) Retrieved from: http://www.normalbreathing.com/index-rate.php

iWorx.  Experiment HS-3: Factors that Affect Breathing Patterns.  Retrieved from: http://www.iworx.com/documents/LabExercises/Breathing-OtherFactors.pdf