Name Lab Sec: Tue Aft Thur Aft
RESPIRATION LAB
Clearly show all calculations.
I. Determine your theoretical vital capacity.
Using your height and weight, determine your approximate surface area from the chart on the front board.
If you are female, multiply that surface area by 2 liters/m
2 and if you are male multiply by 2.5 liters/m2 to get your expected vital capacity.
II. Determine your actual vital capacity.
1. Clean the mouth piece by thoroughly squirting with alcohol and thoroughly rinsing with water.
2. Set up spirometer.
3. To measure vital capacity, the goal is to make the float go up as high as you can. Exhale completely as you can, put mouth tightly around mouth piece and inhale as completely as you can. Have a lab partner mark the height of the float. Record the value:
4. Also record your actual and theoretical on the blackboard
III. Compare
1. How does your vital capacity compare to your theoretical value?
2. On another sheet of paper make a table of the actual and theoretical vital capacities of everyone in the lab section. Do an average and standard deviation of each. How does the theoretical compare to the actual? Make any appropriate comments.
IV. Definitions:
On another sheet of paper make a diagram to show the definitions of vital capacity, inspiratory reserve volume, expiratory reserve volume, tidal volume, and residual volume (use the available human anatomy and physiology texts). In addition, define dead space. Name the anatomical structure(s) primarily responsible for dead space. Know these terms for exam purposes.
V. Respiratory movements:
1. Pick a subject within your group. Preferably a male and preferably someone without a lot of thick clothing.
2. Snugly fit the pneumograph (bellows) around the chest. Make sure it is not connected to the reservoir at this point.
3. Sit the subject down (looking away from the recording) and have them breath normally for 4-5 minutes. Make sure the pattern is being recorded. Determine the respiratory rate:
Assume the tidal volume is 500 ml and the dead space is 150 ml. Then how much useful air is getting to the subject's lungs per minute.
4. Have the subject hold their breath for as long as they can and record their respiratory movements after they again start to breath. What do you observe:
What are the possible internal signals that would force one to start to breath again?
Have the subject deeply inhale and exhale a few times (hyperventilate) and record the subsequent result. What happens? Do you have an explanation?
6. Disconnect the subject and have them run all of the way up and all of the way down the outside stairwell twice! (we want to get them good and winded!). As soon as they return, reconnect them to the apparatus and follow their breathing. Assuming previously recorded tidal volume was 500 ml, and assuming that the apparatus is linear in its measurement, determine the total air per breath now.
Determine how much useful air is getting to the subject's lung's per minute:
Do you think the measurements are linear? Explain:
VI. Usable Minute Volume:
1. Minute volume is a volume of exchange per minute. Usable minute volume for respiration would be the volume of air exchanged per minute excluding the dead space.
2. When we exercise, we tend to breath harder and faster. As you do the following exercise, think about which is better. (Note that as we breath faster there is a tendency to breath less deeply and as we breath harder there is a tendency to breath at a slower rate.)
3. In each of the following cases determine the usable minute volume (assume a dead space of 150 ml) of air exchange.
|
Rate (breaths/min) |
Volume per breath (ml/breath) |
Usable minute volume (Liter/min) |
|
|
1a |
10 |
500 |
3.5 |
|
2a |
20 |
400 |
5 |
|
3a |
30 |
300 |
4.5 |
|
4a |
40 |
200 |
2 |
|
5a |
50 |
100 |
-2.5 |
|
1b |
10 |
500 |
3.5 |
|
2b |
9.5 |
600 |
4.275 |
|
3b |
9 |
700 |
4.95 |
|
4b |
6 |
2000 |
11.1 |
|
5b |
3 |
3000 |
8.55 |
|
6 |
50 |
1500 |
67.5 |
4. After exercise, is it better to take more breaths per minute, or to take larger breaths per breath? EXPLAIN.
5. A kind of hyperventilation is where a person is breathing at a very rapid rate but taking in a very small volume per breath. A person in the this type of hyperventilation may actually suffocate. Explain why.
6. Discuss how all of these considerations would be changed if you were a giraffe or a swan?: