Question

Describe the changes that take place (I) around the rib cage (ii) diaphragm (iii) chest cavity, during inspiration. State the effect of these changes

Answer 1

During inspiration (breathing in), the diaphragm contracts, drawning downward, creating a vacuum in the thoracic cavity. This vacuum inflates the lungs by drawing air into the body through the trachea, or windpipe.
Contraction of the external intercostal muscles moves the ribs upward and outward, causing the rib cage to expand, which increases the volume of the thoracic cavity(chest cavity).