Chapter 20, Problem 1LTB

Describe how contraction of the diaphragm allows the lungs to fill and how oxygen from inhaled air enters the lungs.

Summary Introduction

To determine:

The contraction of diaphragm leads to inhalation.

Introduction:

There are two lungs in the chest cavity that are the primary organs of the respiratory system. There are other components of the respiratory system that transport air to the lungs. These components include trachea and pharynx. The trachea branches into small structures termed as bronchi.

Explanation of Solution

The process of breathing involves two processes, inhalation and exhalation. During exhalation, the carbon dioxide is moved out of the body via the nostrils. During inhalation, the oxygen is moved into the body via the nostrils. The processes of inhalation and exhalation are regulated by the movement of the diaphragm.

When the person inhales the air, the diaphragm contracts and pulls downwards. This leads to the rise and outward movement of the rib’s muscles. It increases the space in the thoracic cavity and decreases the pressure inside. So, when the air pressure in the alveoli decreases down to the atmospheric pressure, the air rushes inside the lungs and fills it.

Conclusion

During inhalation the diaphragm contracts. This leads to the increased space in the thoracic activity and the air rushes into the lungs.