Respiratory System Lab Note: Review the safety materials and wear goggles when working with chemicals. Read the entire exercise before you begin. Take time to organize the materials you will need and set aside a safe work space in which to complete the exercise. Objectives: To define what lung capacity, tidal volume and vital capacity are and how they are related. To measure and estimate lung capacity Relate the effects of exercise on respiration Materials: Metric ruler Metric stick Bathroom scale Spoon Round 9 inch balloons ph test strips Bromothymol blue solution Graduated cylinder (50 ml) Marker pencil Household ammonia Straws Small plastic cups Introduction: Pulmonary ventilation or breathing consists of two phases: inspiration as air is being drawn into the lungs and expiration s air is being blown out of the lungs. Oxygen and carbon dioxide are exchanged in the alveoli of the lungs through diffusion into (oxygen) and out of (carbon dioxide) the blood filled capillaries that surround each alveolus. The depth and speed at which you breathe is determined by the amount of CO2 in your blood. CO2 turns into carbonic acid in blood plasma and can cause the ph of the blood to drop resulting in acidosis. This acidosis can cause cellular damage if it is not regulated and so we adjust our breathing to maintain normal levels of CO2 within our bodies. The respiratory center is the medulla oblongata of the brain stem which contains sensors that detect the amount of CO2 that you have in your bloodstream. The sensors then communicate through nerves with your lungs and heart to increase or decrease respirations and adjust the levels of CO2 in the system. In this activity you will explore the physiology of how this system behaves on your own body. 1. Go to Bio10bcc.weebly.com website, find and watch intro to respiratory system and mechanism of breathing podcast. Answer questions in Lab Report. Activity 1: Measuring Lung Capacity and Volume To accurately measure the full capacity of your lungs, you need to conduct a series of sophisticated breathing tests on equally sophisticated equipment. In this activity you will simulate a lung capacity experiment using less sophisticated equipment to gain a fundamental understanding of your respiratory system. The ability of your lungs to hold a certain volume of air is dependent on several variables. One of the biggest variables is your overall size or body mass. Another variable is your overall fitness. Your fitness will greatly impact your lung capacity, so the results of these tests have a wide range of normal values. #7 Biology 10 Lab Bcc Page 1 of 9
Key Definitions and formulas: 1. Go to bio10bcc.weebly.com website and watch podcast lung capacity measurements under 5 minutes to go along with information given below. There is also a podcast lung capacity mnemonic that may help you remember the terms below. The amount of air we inhale and exhale with each breath is called tidal volume (TV). Our tidal volume provides enough oxygen for our bodies to function at rest. If you inhale and take the deepest breath you can take and then exhale with force pushing as much air out as possible, you will estimate your vital capacity (VC). The vital capacity is the total volume of air your lungs can hold. The inspiratory reserve volume (IRV) is the amount of air that can be forcibly inspired above normal inhalation. The expiratory reserve volume (ERV) is the amount of air that can be forcefully exhaled after normal exhalation. Vital capacity = IRV + TV + ERV = VC Residual volume (RV) is the amount of air left over and cannot be forcefully exhaled from the lungs. Total lung capacity (TLC) =VC + RV Inspiratory capacity (IC) = TV + IRV is the total amount of air that can be inspired after a tidal exhalation Functional residual capacity (FRC) = RV + ERV is the amount of air remaining in the lungs after a tidal exhalation. Remember these are estimations of your lung capacity and vital capacity. If you want actual results you will need to get a test from your physician. #7 Biology 10 Lab Bcc Page 2 of 9
Procedures: 1. Go to bio10bcc.weebly.com website, find and watch how to measure vital capacity with a balloon podcast. 2. Take out a round balloon and stretch it out lengthwise ten times to loosen the latex. 3. Take out a metric ruler 4. Inhale normally and exhale normally into the balloon. NOTE: Do not force your exhale. The balloon will only inflate a small amount. 5. Immediately pinch the end of the balloon off and using the ruler measure the diameter of the balloon at its widest point across. Record the length in centimeters in Data Table 1 in the Lab Report under Tidal Volume. 6. Deflate the balloon and repeat this procedure two more times. Fill in the information in Data Table 1. Calculate your average tidal volume from your three trials and record this into the data table. 7. Take a deep of a breath as you can and forcefully exhale into the balloon as much air as you can. Pinch the end of the balloon off and use the metric ruler to measure the diameter of the balloon at its widest point Record the length in centimeters in Data Table 1 of the Lab Report under Vital Capacity. 8. Deflate the balloon and repeat this procedure two more times. Record the information in Data Table 1. Calculate your average volume for vital capacity from your three trials and record this into the data table. 9. Use the graph in figure 1 in the Lab Report to convert the balloon diameter in Data Table 1 into lung volumes. On the x axis go across and locate the balloon diameter and follow the number up until it meets the curved line on the graph. Then move left in a straight line to the y axis and approximate the lung volume in cubic centimeters. Record the measurements for each trial in Data Table 2 in the Lab Report. 10. Be sure to convert and record BOTH tidal volume and vital capacity from Data Table into Data Table 2. 11. Calculate your average tidal volume and vital capacity based on the conversions in Data Table 2. 12. Next you will estimate your vital capacity based on the surface area of your body. To calculate surface area, you will need to know your height in centimeters and your weight in kilograms. 13. Have your partner measure your height in centimeters using the meter stick. Alternatively, if you know your height in inches, you can convert this to centimeters by multiplying your height by 2.54 (there are 2.54 centimeters in an inch). Record your height in centimeters in Data Table 3 in the Lab Report. 14. If you do not have a good estimate of your weight, weigh yourself on the bathroom scale and make note of the measurement in pounds. To convert your weight in pounds into kilograms, divide your weight by 2.22 (there are approximately 2.22 pounds in a kilogram). Record your weight in kilograms in Data Table 3. #7 Biology 10 Lab Bcc Page 3 of 9
15. Use the following formula to calculate your body surface area (BSA) in m 2. If you need help on doing the math, please go to bio10bcc.weebly.com website and find podcast link How to do math for BSA. If you can do the math, you don t need to watch the podcast. 16. Record your BSA/m 2 in Data Table 3 17. To calculate you estimated vital capacity, multiply your BSA by 2000 ml if you are female and 2500 ml if you are male. Record this number under vital capacity in Data Table 3 18. Go to this bio10bcc.weebly.com website week 7 lab and find and watch spirometry for lung function podcast. Activity 2: Effects of Exercise on Respiration As our level of physical activity increases, our cells begin demanding higher levels of oxygen. Exercise also increases our metabolism and one of the by-products of metabolism is carbon dioxide. Carbon dioxide needs to be removed from our system to prevent cellular damage. Carbon dioxide can damage cells because when it comes in contact with water it turns into an acid. Carbonic acid will cause cellular ph to drop and can start to denature proteins which are vital to our survival. To compensate for the increased levels of CO2 and the resulting carbonic acid it produces, our respiratory system needs to remove the CO2 as quickly as possible. To accomplish this we increase our respiratory rate thus increasing our oxygen intake and removing CO2 more quickly. In this activity, you will test CO2 removal system on yourself to check its efficiency and functionality. Please note: If you have respiratory ailments or other conditions which will prevent you from safely performing the exercises in this activity, you need to notify your instructor immediately. DO NOT PERFORM THIS ACTIVITY IF YOU ARE PREGNANT, HAVE A KNOWN HEART CONDITION OR CHRONIC RESPIRATORY ILLNESS. Procedure: 1. From the supply area, get out a 50-ml graduated cylinder, bromothymol blue solution, ph test strips and a plastic pipet. 2. Get a bottle of household ammonia, 2 or 3 small plastic cups, two drinking straws and a plastic spoon. 3. Label a small plastic cup Ammonia Solution with a marker. 4. Using the graduated cylinder, measure out 100 ml of tap water and pour into the plastic cup. 5. Measure out 4 ml of household ammonia and pour it into the 100 ml of water in the cup. Stir the solution with a spoon. Place the plastic pipet in the cup of ammonia solution. 6. Label a second plastic cup test. Using the graduated cylinder, measure out 100 ml of bromothymol blue solution and pour it into the test cup. 7. Sit in a chair and relax for 5 minutes. 8. After 5 minutes, breathe normally and count the number of breaths you take in one minute (NOTE: if you count for 15 seconds and multiply by 4, you can speed up this step). Record your breaths under the column labeled At Rest in Data Table 4 in the Lab Report. #7 Biology 10 Lab Bcc Page 4 of 9
9. Repeat the above step two more times. Record your breaths in Data Table 4 and then calculate your average number of breaths at rest in the table. 10. Run in place for 1 minute. 11. Return to your chair and count your respirations for 1 minute. Record your information under the column After Exercise in Data Table 4. 12. Repeat Step 10 two more times and record your respirations in Data Table 4. 13. Calculate your average number of respirations after exercise and record this number in Data Table 4. 14. Rest for five minutes or until your breathing returns to normal. 15. Place the drinking straw in the test cup and breathe in through your nose and out through the straw into the bromothymol blue solution for exactly one minute. The solution should turn yellow. Bromothymol blue is an aid indicator. When you blow into the solution you are putting CO2 into the liquid making carbonic acid. AS the ph of the solution drops, the solution will turn green and then yellow. 16. After the minute is up, take a ph test strip and dip it into the test cup. Pull out the paper and compare it to the color scale. Record the ph of the solution in the appropriate place in the Lab Report. 17. Squeeze and fill the dropper pipet from the cup with ammonia solution and start adding drops of the solution to your test cup. Stir the solution with your straw in between drops. Count the number of drops as you go and add enough ammonia solution into the test cup to turn the solution back to blue. Be sure to sir with the straw between drops. When the test solution turns blue AND stays blue after stirring, you can stop adding drops. Record the number of drops of ammonia you added in the At Rest column in Data Table 5 in the Lab Report. 18. Repeat Steps 15 to 17 two more times and record the results in Data Table 5. 19. Calculate the average number of ammonia drops and record this under the At Rest column in Data Table 5. 20. Pour out the bromothymol blue solution from the test cup into the sink. Rinse and dry the cup and refill it with 100 ml of new bromothymol blue solution. 21. Replace the old drinking straw with a new one. 22. Run in place for one minute. 23. After one minute of exercise, breathe in through your nose and out through the straw into the test cup for exactly one minute. The solution should turn yellow. 24. Squeeze and fill the dropper pipet from the cup with ammonia solution and start adding drops of the solution to your test cup. Stir the solution with your straw in between drops. Count the number of drops as you go and add enough ammonia solution into the test cup to turn the solution back to blue. Be sure to stir with the straw between drops. When the test solution turns blue AND stays blue after stirring, you can stop adding drops. Record the number of drops of ammonia you added in the After Exercise column in Data Table 5 in the Lab Report. 25. Repeat Steps 22 through 24 two more times and record the results in Data Table 5. 26. Calculate the average number of drops of ammonia and record this under the After Exercise column in Data Table 5. 27. Answer the questions in the Lab Report. #7 Biology 10 Lab Bcc Page 5 of 9
Lab Report: Respiratory System Purpose: Please explain the purpose of this lab. Include in your explanation the major concepts you learned and any safety concerns associated with the lab. #7 Biology 10 Lab Bcc Page 6 of 9
Activity 1 Measuring Lung Capacity Observations Data Table 1: Balloon Diameter (cm) Trial Tidal Volume Vital Capacity 1 2 3 Average Data Table 2: Lung Volume (cm 3 ) Trial Tidal Volume Vital Capacity 1 2 3 Average Data Table 3: Estimated Vital Capacity Body Data Component Height in cm Figure 1: Lung Volumes Weight lbs kg Surface Area Vital Capacity m 2 m 3 #7 Biology 10 Lab Bcc Page 7 of 9
Questions: 1. Why is it important to calculate averages for measurements in this exercise? 2. How does your estimated vital capacity compare with the measured vital capacity? 3. Why is it important to know a person s vital capacity or tidal volume? 4. Do some research: How does smoking effect vital capacity? 5. Calculate the total lung capacity (TLC) of a person who has an RV of 1205 m, an ERV of 1180, a TV of 505, and an IRV of 2950. Is this person male or female? 6. Calculate the functional residual capacity (FRC) of a person with an expiratory reserve volume (ERV) of 800 ml and a residual volume (RV) of 1095 ml. Is this person a male or female? 7. What is the inspiratory capacity (IC) of a person with a tidal volume of 505 ml and an inspiratory reserve volume (IRV) of 1950 ml)? Is this person male or female? #7 Biology 10 Lab Bcc Page 8 of 9
Activity 2: Effects of exercise on Respiration Observations. Data Table 4: Breathing Rate Trial At Rest After Exercise 1 2 3 Average Data Table 5: Number of Ammonia Drops Trial At Rest After Exercise 1 2 3 Average Questions: 1. What effect does exercise have on the amount of carbon dioxide released by the blood? 2. Why do your respirations go up as you exercise? 3. What did the ammonia drops represent in the body? 4. Do some research: Why do athletes prefer to train in high altitude locations? What effect does this training have on respiration? 5. Do some research: What kinds of information would a physician gain by running a lung capacity test on someone? In other words, why would a physician run such a test? #7 Biology 10 Lab Bcc Page 9 of 9