Cardiopulmonary Anatomy & Physiolo...

7th Edition
Des Jardins + 1 other
ISBN: 9781337794909



Cardiopulmonary Anatomy & Physiolo...

7th Edition
Des Jardins + 1 other
ISBN: 9781337794909
Textbook Problem

In the normal individual in the upright position

1. the negative pleural pressure is greater (i. e., more negative) in the upper lung regions.

2. the alveoli in the lower lung regions are larger than the alveoli in the upper lung regions.

3. ventilation is more effective in the lower lung regions.

4. the pleural pressure is always below atmospheric pressure during a normal ventilator cycle.

A. 1 and 2 only

B. 2 and 3 only

C. 2,3 and 4 only

D. 1,3, and 4 only

Summary Introduction


The intrapleural pressure is the pressure within the pleural cavity which is slightly less than the atmospheric pressure, and is known as negative pressure. The alveoli are the small air sacs that allow gas to diffuse in the lungs and the bloodstream, and increases the surface area of diffusion. The process of respiration starts with pulmonary ventilation. The ventilation occurs due to the pressure gradient between the atmospheric air and the pulmonary air. The pressure difference arises when the volume of the pulmonary cavity changes.


Justification/ Explanation for the correct answer:

Option (d) states that 1, 3 and 4 are correct. The intrapleural pressure is responsible for inspiration. This pressure decreases so that air comes in, and is less than the atmospheric pressure. The upper region of the lung has more negative or greater intrapleural pressure in the upright position. The ventilation in the lower region of the lungs is more effective in the upright position because the pulmonary pressure increases at the base, which means it becomes more negative because of gravity and the weight of the lungs in the upright position. The intrapleural pressure is always below the atmospheric pressure, because if it exceeds, the intrapleural pressure becomes positive and the lung will collapse. Hence, option (d) is the correct answer...

Still sussing out bartleby?

Check out a sample textbook solution.

See a sample solution

The Solution to Your Study Problems

Bartleby provides explanations to thousands of textbook problems written by our experts, many with advanced degrees!

Get Started

Additional Science Solutions

Find more solutions based on key concepts

Show solutions add

Microorganisms can cause foodborne illness either by infection or by intoxication.

Nutrition: Concepts and Controversies - Standalone book (MindTap Course List)

How do eating disorders affect health?

Understanding Nutrition (MindTap Course List)

How many autosomes are present in a body cell of a human being? In a gamete?

Human Heredity: Principles and Issues (MindTap Course List)