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Multiple Choice
Which muscles are activated during forced expiration?
A
External intercostal muscles
B
Diaphragm
C
Scalene muscles
D
Internal intercostal muscles
Verified step by step guidance
1
Understand the process of forced expiration: Forced expiration is an active process that involves the contraction of specific muscles to expel air from the lungs more forcefully than during normal breathing.
Identify the muscles involved in normal expiration: Normal expiration is typically a passive process that relies on the elastic recoil of the lungs and relaxation of the diaphragm and external intercostal muscles.
Recognize the role of internal intercostal muscles: During forced expiration, the internal intercostal muscles contract to pull the ribs downward and inward, reducing the volume of the thoracic cavity and increasing the pressure to expel air.
Differentiate between internal and external intercostal muscles: The external intercostal muscles are primarily involved in inspiration, helping to elevate the ribs, whereas the internal intercostal muscles assist in forced expiration by depressing the ribs.
Consider the role of accessory muscles: While the diaphragm and scalene muscles are involved in inspiration, they do not play a direct role in forced expiration. Instead, muscles like the abdominal muscles may also assist in increasing intra-abdominal pressure during forced expiration.