A person forcefully exhales air to blow out the candles on a birthday cake. Which of the following sets of muscle activities is primarily responsible for this forceful expiration?

Step-by-step solution

Normal expiration is a passive process that occurs due to the relaxation of the diaphragm and external intercostal muscles, returning the thoracic cavity to its original volume. However, forceful expiration is an active process. According to NCERT, we have the ability to increase the strength of expiration with the help of additional muscles in the abdomen. Along with abdominal muscles, the contraction of internal intercostal muscles further pulls the ribs downward and inward. This actively decreases the volume of