The heart, vessels and blood flow
Grade 7 Science Worksheet - Challenge Me

Circle the best answer, or write your answer on the line.
A red blood cell leaves the lungs in a pulmonary vein. Which path does it take next, Ari?
- Right atrium, right ventricle, lungs
- Left ventricle, lungs, body
- Straight to the body, skipping the heart
- Left atrium, left ventricle, body
A red blood cell in a toe heads back toward the heart. How many times does it pass through the heart before reaching the toe again, Bo?
- Zero: it skips the heart
- Twice: right side, then left side
- Three times
- Once: straight back to the toe
Esme lists a path: right ventricle → lungs → left atrium → left ventricle. Which step comes just before the right ventricle?
- Lungs
- Right atrium
- Left ventricle
- Left atrium
The pulmonary artery carries oxygen-poor blood from the heart to the lungs. Why is it still called an artery, Jun?
- It is a capillary
- It carries blood back to the heart
- It carries oxygen-rich blood
- It carries blood away from the heart
The pulmonary veins carry oxygen-rich blood from the lungs to the heart. Why are they veins, Kira?
- They have walls one cell thick
- Veins carry oxygen-poor blood by definition
- They carry blood back to the heart
- They carry blood away from the heart
Luz must label the vessel taking blood from the right ventricle to the lungs. Which label is right?
- Pulmonary vein, as the blood is oxygen-poor
- Aorta
- Capillary
- Pulmonary artery
Noah says oxygen passes into body cells through the walls of big arteries. Agree or disagree?
- Agree: veins and arteries both let it through
- Agree: arteries carry the oxygen, so it leaves there
- Disagree: it passes through capillaries
- Disagree: oxygen stays in the blood
A resting adult's heart beats about 75 times a minute and pumps about 70 mL each beat. About how many mL does it pump in a minute, Ren?
Another heart at rest beats 60 times a minute and pumps 80 mL each beat. How many mL does it pump in a minute, Tala?
During a bike ride, a heart beats 120 times a minute and pumps 90 mL each beat. How many mL does it pump in a minute, Zee?