What is the function of accessor muscles during breathing?

• A. Assist in normal expiration
• B. Enhance forced inhalation during exertion
• C. Control the opening of the larynx
• D. Filter dust and particles from air

Answer: (B)

The function of accessory muscles during breathing primarily involves assisting in forced inhalation, especially during periods of increased physical demand, such as during exercise or respiratory distress. Accessory muscles include various muscle groups, such as the sternocleidomastoid and scalene muscles, which help elevate the rib cage and increase the thoracic cavity's volume beyond what is achieved through the diaphragm and intercostal muscles alone.

When the body requires additional oxygen or needs to expel more carbon dioxide quickly, engaging these accessory muscles allows for a greater influx of air into the lungs. This mechanism is particularly important during situations of exertion, such as intense workouts or respiratory illnesses where normal breathing may not suffice. Thus, their role in enhancing forced inhalation is critical for meeting the body's increased oxygen demands and for efficient gas exchange.