The video explains the mechanics of breathing, focusing on air pressure and its role in inspiration and expiration. It describes how air pressure differences drive air in and out of the lungs, detailing the roles of the diaphragm and intercostal muscles. The video also covers active expiration during exercise, highlighting the use of internal intercostal muscles.

What is air pressure measured by?

• The weight of air

• The temperature of air

• The number of air particles in a given volume

• The humidity level of air

What happens when there is a difference in air pressure?

• Air remains static

• Air pressure automatically stabilizes

• Air moves from high to low pressure

• Air moves from low to high pressure

Which muscles contract during inspiration?

• External intercostal muscles

• Abdominal muscles

• Internal intercostal muscles

• Pectoral muscles

What happens to the diaphragm during inspiration?

• It remains unchanged

• It contracts and flattens

• It relaxes and flattens

• It contracts and domes upwards

How does the thoracic cavity change during inspiration?

• Its volume decreases

• Its pressure increases

• Its pressure remains the same

• Its volume increases

What triggers air to flow into the lungs?

• Increased pressure in the thoracic cavity

• Decreased volume of the thoracic cavity

• Decreased pressure in the thoracic cavity

• Increased volume of the thoracic cavity

How does air pressure inside the lungs compare to outside during inspiration?

• It is lower inside

• It fluctuates rapidly

• It is higher inside

• It is the same

What role do the internal intercostal muscles play during exercise?

• They relax to aid in inspiration

• They contract to pull the ribcage down, aiding in expiration

• They help in lifting the ribcage up and out

• They contract to increase the thoracic cavity volume

What is the primary change in the thoracic cavity during expiration?

• Volume increases

• Pressure decreases

• Volume decreases

• Pressure remains constant

What effect does aerobic exercise have on the ribs the next day?

• They become more flexible

• They may feel tighter

• They may feel sore due to the internal intercostal muscles' strain

• No effect