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Exercise 7: Respiratory System Mechanics: Activity 3: Effect of Surfactant and Intrapleural Pressure on Respiration Lab Report

Pre-lab Quiz Results

You scored 100% by answering 5 out of 5 questions correctly.

1. Which of the following statements about surface tension is false?

You correctly answered: c. Surface tension acts to increase the size of the alveoli within the lungs.

2. Which of the following statements about surfactant is false?

You correctly answered: d. Surfactant works by increasing the attraction of water molecules to each other.

3.Just before an inspiration begins, the pressure within the intrapleural cavity You correctly answered: b. is less than the pressure within the alveoli.

4.The respiratory condition of pneumothorax refers to

You correctly answered: c. any opening that equalizes the intrapleural pressure with the atmospheric pressure.

5. A pneumothorax can lead to

You correctly answered: b. atelectasis.

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Experiment Results

Predict Question:

Predict Question 1: What effect will adding more surfactant have on these lungs?

Your answer : b. Airflows will further increase.

Predict Question 2: What will happen to the collapsed lung in the left side of the glass bell jar if you close the valve? Your answer : b. The lung will reinflate over several breaths.

Stop & Think Questions:

Why did the sequential additions of surfactant change this lung system?

You correctly answered: a. Surface tension was sequentially decreased.

Premature infants often have difficulty breathing because the amount of surfactant in their lungs is

You correctly answered: b. too low.

What happened to the left side of the bell jar when the valve was opened?

You correctly answered: b. The intrapleural pressure equalized with the atmospheric pressure.

Did the collapsed left lung reinflate?

You correctly answered: b. No, it did not.

Experiment Data:

Radius

Breath Rate

Surfactant

Pressure Left

Pressure Right

Flow Left

Flow Right

Total Flow

5

15

0

-4

-4

49.69

49.69

99.38

5

15

2

-4

-4

69.56

69.56

139.13

5

15

4

-4

-4

89.44

89.44

178.88

 

 

 

 

 

 

 

 

5

15

0

-4

-4

49.69

49.69

99.38

5

15

0

0.00

-4

0.00

49.69

49.69

 

 

 

 

 

 

 

 

5

15

0

0.00

-4

0.00

49.69

49.69

5

15

0

-4

-4

49.69

49.69

99.38

 

 

 

 

 

 

 

 

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Post-lab Quiz Results

You scored 100% by answering 4 out of 4 questions correctly.

1.The addition of surfactant to the lung interior You correctly answered: c. increased airflow.

2.Opening the valve in the side of the glass bell jar You correctly answered: d. simulated pneumothorax.

3.In this activity a pneumothorax is automatically followed by You correctly answered: b. atelectasis.

4.The best way to rapidly reinflate a person's collapsed lung is to

You correctly answered: a. pump air out of the intrapleural space to recreate negative pressure.

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Review Sheet Results

1.What effect does the addition of surfactant have on the airflow? How well did the results compare with your prediction? Your answer:

Addition of surfactant in the lungs cause an increase on the airflow. surfactant reduce friction.

2.Why does surfactant affect airflow in this manner?

Your answer:

Surfactant decrease surface tention by reducing the attraction of water molecules to each other. so therefore, it increase airflow.

3.What effect did opening the valve have on the left lung? Why does this happen? Your answer:

Opening the valve cause the left lung to flatten out and kind of unfuctional. The opening created in the pleural membranes equalize the intrapleural pressure with atmospheric pressure by allowing air to enter the plural cavity.

4.What effect on the collapsed lung in the left side of the glass bell jar did you observe when you closed the valve? How well did the results compare with your prediction?

Your answer:

When I close the valve, there was still no effect on the collapsed lungs, the lungs did not reinflate. My hypothesis was incorrect. I thought the lung will reinflate over several breath.

5.What emergency medical condition does opening the left valve simulate?

Your answer:

Pneumothorax is a codition that is caused when opening the left valve simulate.

6.In the last part of this activity, you clicked the Reset button to draw the air out of the intrapleural space and return the lung to its normal resting condition. What emergency procedure would be used to achieve this result if these were the lungs in a living person?

Your answer:

I think pumping air out from the intrapleural space and return the lung to its normal resting condition would help in a living persoon.

7.What do you think would happen when the valve is opened if the two lungs were in a single large cavity rather than separate cavities?

Your answer:

Both of the lungs would collapsed cause airflow problems and that would result in a death of that person.

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