Veins are blood vessels that take blood from cells back to the heart.

Valves are flaps that act like doors to keep blood flowing in one direction.

The circulatory system is the body’s transportation system.

Cells do not need oxygen to get energy from food.

A system is a group of smaller parts working together to get a job done.

The circulatory system includes the heart, blood, and blood vessels.

___________ makes up a little more than half of the blood. It carries the blood cells.

The red blood cells carry ____________ to your body’s cells.

When a blood vessels is cut, _____________ are there to stop the bleeding.

Surrounds the animal cell.

Where the organs work together.

Where tissues work together.

Part of the cell that stores DNA.

Blood vessels that carry blood away from heart

from other parts of the body.