Final answer:
Due to the bucket handle movement during inhalation, the volume of the ribcage increases as the external intercostal muscles contract to lift the rib cage, allowing for air to flow into the lungs.anawer is option a.
Step-by-step explanation:
The concept of the bucket handle movement is central to understanding the mechanics of breathing, particularly during inhalation. During inhalation, the contraction of the external intercostal muscles causes the rib cage to lift and expand. As the ribs move upward and outward, the volume of the thoracic cavity increases.
This is due to the creation of more space for the lungs to expand, and as a result, the volume inside the pleural cavities increases, decreasing the internal pressure. According to Boyle's Law, when the volume increases, the pressure decreases, and thus air flows into the lungs. Consequently, the correct answer to the student's question is (a) Increases.Due to the bucket handle movement during inhalation, the volume of the ribcage increases as the external intercostal muscles contract to lift the rib cage, allowing for air to flow into the lungs.