P5 Respiration

Which of the following are parts of the respiratory system?

• mouth

• windpipe

• heart

• lungs

• blood

Which gas is most abundant in the air that we breathe in?

• carbon dioxide

• oxygen

• water vapour

• nitrogen

The air that we exhale contains only carbon dioxide as the oxygen has been used up by our body.

• True

• False

Gaseous exchange in a human takes place at the ___________.

• lungs

• windpipe

• nostrils

• heart

_____________ can be found at the end of the air tubes in our lungs.

The air sacs are covered with numerous tiny blood vessels called ___________.

• arteries

• veins

• capillaries

• red blood cells

How are our air sacs adapted for gaseous exchange?

• They are thick to absorb more oxygen.

• Their high numbers increase the surface area for gaseous exchange.

• They are surrounded with blood vessels to exchange oxygen and carbon dioxide.

• They trap dust and dirt so clean air enters the blood.

At the lungs, _____________ enters the blood.

_____________ leaves the blood at the lungs.

Our lungs expand when we inhale and contract when we exhale.

• True

• False