The Heart and Circulatory System

What You'll Learn

The circulatory system includes the heart, blood vessels, and blood. Arteries carry oxygen-rich blood away from the heart, and veins return oxygen-poor blood to the heart.

Key Words

respiratory system
circulatory system

Steps

Step 1 — Read

Read and learn: The circulatory system includes the heart, blood vessels, and blood. Arteries carry oxygen-rich blood away from the heart, and veins return oxygen-poor blood to the heart.

Step 2 — Do

Gather your materials and set up your workspace.

Step 3 — Observe

Watch carefully for any changes and note the time.

Step 4 — Record

Create a data table to organize your measurements.

Check Your Understanding

Question 1

1 of 3

What system defends the body against germs?