Final answer:
The chest wall does not recoil outwards at the end of quiet expiration because expiration is passive, the elastic recoil of the lungs, and the relaxation of the intercostal muscles and diaphragm counteract the outward recoil of the chest wall.
Step-by-step explanation:
The chest wall does not recoil outwards at the end of quiet expiration because the process of expiration is a passive event. Although the chest wall has a tendency to recoil outwards due to its elasticity, this is countered by the relaxation of the intercostal muscles and diaphragm and the elastic recoil of the lungs. As a result, the intrapleural pressure within the thoracic cavity returns to a resting state, and the lungs recoil, pushing air out passively. The pleural fluid also plays a role in ensuring the lungs stay close to the thoracic wall, moving together during the respiratory cycle.