Human Anatomy and Physiology : Help with Lower Respiratory Physiology

Study concepts, example questions & explanations for Human Anatomy and Physiology

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Example Questions

Example Question #12 : Respiratory Physiology

Contraction of the diaphragm and intercostal muscles during inspiration causes what type of pressure change within the pleural space (area outside the lungs but within the chest cavity)?

Possible Answers:

No change in pressure

Becomes more positive

Negative pressure change

More information is needed to answer the question

Positive pressure change

Correct answer:

Negative pressure change

Explanation:

The correct answer is a negative pressure change within the pleural space. When the diaphragm and intercostal muscles contract, they expand the chest cavity creating a higher volume of space within the pleural space. As volume within this space increased, the pressure responds by decreasing. This drop in pressure within the pleural space causes air from outside the body (high pressure) to low pressure (within the chest and the lungs).

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