Answers Lab10 RespPhysiology
M37_MARI0000_00_SE_CH37.qxd
3/29/11
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R E V I E W
S H E E T
NAME ____________________________________
EXERCISE
LAB TIME/DATE _______________________
37
Respiratory System
Physiology
Mechanics of Respiration
1. For each of the following cases, check the column appropriate to your observations on the operation of the model lung.
Diaphragm pushed up
Change
Increased
Decreased
✓
✓
✓
✓
In the size of the balloons (lungs)
In direction of air flow
Increased
✓
In internal volume of the bell jar
(thoracic cage)
In internal pressure
Decreased
Diaphragm pulled down
Into lungs
Out of lungs ✓
✓
Into lungs ✓
Out of lungs
2. Base your answers to the following on your observations in question 1.
Under what internal conditions does air tend to flow into the lungs? ↑ thoracic volume, and ↓ pressure.
Under what internal conditions does air tend to flow out of the lungs? Explain why this is so. ↓ thoracic volume, ↑ pressure.
Gases move in the direction that tends to equalize pressure inside and outside the “container.”
3. Activation of the diaphragm and the external intercostal muscles begins the inspiratory process. What effect does contraction of these muscles have on thoracic volume, and how is this accomplished? ↑ thoracic volume. The diaphragm moves inferiorly, increasing the superior/inferior dimension; the ribs swing up and out, increasing the lateral and anterior/posterior dimensions.
4. What was the approximate increase in diameter of chest circumference during a quiet inspiration? (student data)
During forced inspiration? (student data)
inches
inches
237
Copyright © 2011 Pearson Education, Inc.
M37_MARI0000_00_SE_CH37.qxd
3/29/11
2:34 PM
Page 238
What temporary physiological advantage is created by the substantial increase in chest circumference during forced inspiration? Increases the thoracic volume more; therefore, creates a greater negative internal pressure, causing the gases to rush in quickly. Also, more “fresh”
3/29/11
2:34 PM
Page 237
R E V I E W
S H E E T
NAME ____________________________________
EXERCISE
LAB TIME/DATE _______________________
37
Respiratory System
Physiology
Mechanics of Respiration
1. For each of the following cases, check the column appropriate to your observations on the operation of the model lung.
Diaphragm pushed up
Change
Increased
Decreased
✓
✓
✓
✓
In the size of the balloons (lungs)
In direction of air flow
Increased
✓
In internal volume of the bell jar
(thoracic cage)
In internal pressure
Decreased
Diaphragm pulled down
Into lungs
Out of lungs ✓
✓
Into lungs ✓
Out of lungs
2. Base your answers to the following on your observations in question 1.
Under what internal conditions does air tend to flow into the lungs? ↑ thoracic volume, and ↓ pressure.
Under what internal conditions does air tend to flow out of the lungs? Explain why this is so. ↓ thoracic volume, ↑ pressure.
Gases move in the direction that tends to equalize pressure inside and outside the “container.”
3. Activation of the diaphragm and the external intercostal muscles begins the inspiratory process. What effect does contraction of these muscles have on thoracic volume, and how is this accomplished? ↑ thoracic volume. The diaphragm moves inferiorly, increasing the superior/inferior dimension; the ribs swing up and out, increasing the lateral and anterior/posterior dimensions.
4. What was the approximate increase in diameter of chest circumference during a quiet inspiration? (student data)
During forced inspiration? (student data)
inches
inches
237
Copyright © 2011 Pearson Education, Inc.
M37_MARI0000_00_SE_CH37.qxd
3/29/11
2:34 PM
Page 238
What temporary physiological advantage is created by the substantial increase in chest circumference during forced inspiration? Increases the thoracic volume more; therefore, creates a greater negative internal pressure, causing the gases to rush in quickly. Also, more “fresh”