Chapter 7, Problem 7RQ

Which of the following muscles aid(s) in deep expiration? a. the scalenes b. the sternocleidomastoids c. the rectus abdominis d. the external intercostals e. the erector spinae

Expansion of the chest cavity during normal relaxed breathing is accomplished by the diaphragm and______   A. external/internal abdominal oblique   B. intercostals   C. pectoralis major   D. trapezius

The action of the diaphragm and intercostal muscles The diagram below shows inhalation and exhalation.                             Complete the following sentences to explain how we breathe in. The intercostal muscles between the _______________ This moves the ribs _______________ and _______________. At the same time, the diaphragm muscle _______________ and moves _______________. The volume of air inside the chest _______________. This decreases the pressure inside the chest. The air pressure outside the chest is higher so air enters the lungs. Complete the following sentences to explain how we breathe out. The intercostal muscles _______________. The ribs are moved _______________ and _______________. At the same time, the diaphragm muscle _______________ and moves _______________. The volume of air inside the chest __________________. This increases the pressure inside the chest. The air pressure outside the chest is now lower so air leaves the lungs.