Respiratory System and Gas Exchange Quiz

What determines an organism's oxygen requirement?

• The organism's speed

• The organism's color

• The organism's weight

• The organism's volume

Which feature is NOT common to respiratory surfaces?

• Thick to provide a long diffusion distance

• Large surface area relative to volume

• Permeable

• Moist to dissolve gases

What reduces friction with the ribs during breathing?

• Blood

• Surfactant

• Pleural fluid

• Mucus

What is the role of surfactant in the alveoli?

• To reduce surface tension

• To increase surface tension

• To dry the alveoli

• To thicken the alveoli walls

What is the approximate concentration of oxygen in fresh air?

• 40%

• 10%

• 30%

• 20%

What happens to the pressure in the thorax when its volume increases?

• Pressure increases

• Pressure fluctuates

• Pressure decreases

• Pressure remains the same

What is the main function of the alveoli?

• To store oxygen

• To filter air

• To produce mucus

• To exchange gases

How thick are the walls of the alveoli?

• One cell thick

• Two cells thick

• Three cells thick

• Four cells thick

What maintains the concentration gradient in the lungs?

• Gravity

• Humidity

• Temperature

• Ventilation

What is the role of the diaphragm in breathing?

• To increase lung volume

• To moisten air

• To decrease lung volume

• To filter air