Which blood vessel carries blood back to the heart?
Veins.
What is heartbeat?
The contraction and relaxation of the heart muscle.
What part of the blood helps fight infection?
White blood cells.
What part of the blood helps to stop bleeding by clotting?
Platelets.
What is plasma mostly made of?
Water.
What organ pumps blood around the body?
The heart.
Which blood vessel is very thin and allows exchange of oxygen and carbon dioxide?
Capillaries.
Why are valves in veins important?
They stop blood from flowing backwards.
What is the function of plasma in the blood?
To carry nutrients, hormones, and waste products.
What is a pulse?
The pressure wave in arteries when the heart pumps blood.
Name the three main types of blood vessels.
Arteries, veins, and capillaries.
Name one waste product carried by the blood.
Carbon dioxide.