Respiratory System Mechanics

The video tutorial explains the breathing process, focusing on inspiration and expiration. During inspiration, the diaphragm contracts, causing the ribcage to move up and out, decreasing lung pressure and allowing air to rush in. In expiration, the diaphragm relaxes and becomes dome-shaped, while the ribcage moves down and in, increasing lung pressure and pushing air out.

What happens to the pressure in the lungs during inspiration?

• It remains constant

• It decreases

• It increases

• It fluctuates

Which muscle contracts to help the lungs fill with air during inspiration?

• Intercostal muscles

• Abdominal muscles

• Diaphragm

• Pectoral muscles

During inspiration, in which direction does the ribcage move?

• It does not move

• Sideways

• Downwards and inwards

• Upwards and outwards

What shape does the diaphragm take during expiration?

• Flat

• Dome-shaped

• Square

• Triangular

What happens to the ribcage during expiration?

• It moves upwards and outwards

• It moves downwards and inwards

• It remains stationary

• It expands