Which term describes taking air into the lungs?

Which term describes taking air into the lungs?

• A. Expansion
• B. Inspiration
• C. Expiration
• D. Circulation

Answer: (B)

Taking air into the lungs is called inspiration. During inspiration, the diaphragm contracts and moves downward while the chest muscles lift the ribs, expanding the thoracic cavity. This expansion lowers the air pressure inside the lungs, so air flows in from outside until the pressures inside and outside balance. Expiration, by contrast, is the act of exhaling air out as the lungs recoil and the chest cavity decreases in size. Circulation is about moving blood through the body, not breathing. Expansion is a general term for increasing size, but the specific term for drawing air into the lungs is inspiration.

Taking air into the lungs is called inspiration. During inspiration, the diaphragm contracts and moves downward while the chest muscles lift the ribs, expanding the thoracic cavity. This expansion lowers the air pressure inside the lungs, so air flows in from outside until the pressures inside and outside balance. Expiration, by contrast, is the act of exhaling air out as the lungs recoil and the chest cavity decreases in size. Circulation is about moving blood through the body, not breathing. Expansion is a general term for increasing size, but the specific term for drawing air into the lungs is inspiration.