GCSE PE: Alveoli as the site of gaseous exchange

Gas exchange occurs at ...

• the alveoli in the heart and takes place by diffusion.

• the alveoli in the muscles and takes place by diffusion.

• the alveoli in the lungs and takes place by diffusion.

• the capillaries in the heart.

The alveoli are surrounded by ...

• Veins

• Arteries

• Capillaries

• Bronchi

Diffusion is ...

• the movement of nutrients from an area of high concentration to a low concentration.

• the movement of blood from an area of low concentration to a high concentration.

• the movement of gas from an area of high concentration to a high concentration.

• the movement of gas from an area of high concentration to a low concentration.

There is a high concentration of (a)   in the blood and low concentration of (b)   in the alveoli, so (c)   diffuses from the blood into the alveoli.

• Oxygen

• Carbon Dioxide

• Nitrogen

• Hydrogen

Both oxygen and carbon dioxide are capable of combining with an iron-rich protein in the blood called ...

• albumin

• Geoff

• myoglobin

• haemoglobin

Haemoglobin carries ...

• oxygen to be exchanged at the working muscle and air to be exchanged at the lung.

• carbon dioxide to be exchanged at the working muscle and oxygen to be exchanged at the lung.

• oxygen to be exchanged at the working muscle and carbon dioxide to be exchanged at the lung.

• nitrogen to be exchanged at the working muscle and carbon dioxide to be exchanged at the lung.

Capillaries ..

• link the lungs to the heart

• surround the alveoli in the heart

• surround the alveoli in the lungs.

• have valves

Both capillaries and alveoli are ...

• are very thick

• have valves

• impermeable

• very thin

Capillaries and alveoli are just one cell thick. They are made of ...

• semi-permeable membranes

• impermeable membranes

• ligaments

• permeable membranes

Semi-permeable membranes allows ...

• allows water to pass through them

• oxygen and carbon dioxide to not pass through them

• oxygen and carbon dioxide to pass through them

• allows blood to pass through them