The heart, vessels and blood flow

Grade 7 Science Worksheet

Circle the best answer.

1. 1.

   Ari's path reads: body → right atrium → right ventricle → ? → left atrium. What fills the blank?

   • Lungs
   • Stomach
   • Body
   • Left ventricle
2. 2.

   Esme's path reads: left ventricle → body → ? → right ventricle. What fills the blank?

   • Left ventricle
   • Right atrium
   • Left atrium
   • Lungs

3. Read this first

   Numbered path, not to scale

   1 body → 2 right atrium → 3 right ventricle → 4 lungs → 5 left atrium → 6 left ventricle → 7 body.

4. 3.

   Blood in the left ventricle is oxygen-rich. Where did it just come from, Jun?

   • The lungs
   • The stomach
   • The right ventricle
   • The body
5. 4.

   Why is the left ventricle's wall thicker than the right's, Kira?

   • It makes oxygen
   • It pumps blood around the whole body
   • It stores extra blood
   • It pumps blood just to the lungs
6. 5.

   During Milo's run, leg muscles need oxygen. Where does oxygen leave the blood and enter the muscle cells?

   • In the heart
   • In the veins
   • In the big arteries
   • In the capillaries
7. 6.

   Why are capillaries good places for things to pass between blood and cells, Noah?

   • Their walls are the thickest in the body
   • They have no blood in them
   • They are as wide as arteries
   • Their walls are one cell thick
8. 7.

   Arteries have thick, muscular walls. What is that thick wall good for, Pia?

   • Making blood
   • Carrying blood pushed hard from the heart
   • Bringing blood back to the heart
   • Letting oxygen pass out to cells
9. 8.

   Ren bikes up a hill, and the heart beats faster. Why does it beat faster?

   • To send more blood to the muscles
   • To send less blood to the muscles
   • To skip the lungs
   • To make more oxygen in the heart
10. 9.

    During a race, vessels to Tala's leg muscles widen. What does that do?

    • Blood stops in the legs
    • More blood reaches the leg muscles
    • Less blood reaches the leg muscles
    • Blood goes back without the lungs
11. 10.

    After a hard game, Zee breathes fast and the heart beats fast. How do the two systems work together?

    • The left side sends blood to the lungs
    • They work apart
    • The heart makes oxygen; the lungs pump it
    • Lungs load oxygen; the heart pumps it out