Respiration and Circulation

Tiny air sacs in the lungs where oxygen and carbon dioxide are exchanged.

A protein produced by certain white blood cells that helps destroy pathogens.

The largest artery in the body, carrying oxygen-rich blood from the left ventricle to the body.

A blood vessel that carries blood away from the heart.

A specialised connective tissue that transports substances throughout the body.

The force exerted by blood against the walls of arteries.

The two main air passages that carry air from the trachea into the lungs.

Smaller branches of the bronchi that lead to the alveoli.

A tiny blood vessel with walls only one cell thick.

A waste gas produced during cellular respiration.