The circulatory and respiratory systems working together

Grade 9 Science Worksheet

Circle the best answer.

1. Read this first

   Use this

   Map of blood flow (model, not to scale). Arrows, each marked with what it carries: body to right atrium, oxygen-poor blood; right atrium to right ventricle, oxygen-poor blood; right ventricle to lungs, oxygen-poor blood; lungs to left atrium, oxygen-rich blood; left atrium to left ventricle, oxygen-rich blood; left ventricle to body, oxygen-rich blood. The red blood cell starts on the arrow marked oxygen-rich blood that leaves the lungs.

2. 1.

   Jun follows a red blood cell that has just left the lungs in a pulmonary vein. Which places does it pass through next, in order?

   • Left ventricle, left atrium, aorta, then the body
   • Left atrium, aorta, left ventricle, then the body
   • Right atrium, right ventricle, pulmonary artery, then the lungs
   • Left atrium, left ventricle, aorta, then the body

3. Vessel X card (textbook facts)

   vessel	blood goes from	blood goes to	oxygen in the blood
   X	the right ventricle	the lungs	low

4. 2.

   Milo reads a card about vessel X. Which words describe vessel X?

   • An artery, because it carries blood away from the heart
   • A capillary, because it ends in the lungs
   • A vein, because it carries blood to the lungs
   • A vein, because its blood is low in oxygen

5. Vessel Y card (textbook facts)

   vessel	blood goes from	blood goes to	oxygen in the blood
   Y	the lungs	the left atrium	high

6. 3.

   Noah reads a card about vessel Y. Which words describe vessel Y?

   • A capillary, because it is part of the lungs
   • An artery, because it comes out of the lungs
   • An artery, because its blood is high in oxygen
   • A vein, because it carries blood toward the heart

7. Vessel Z card (textbook facts)

   vessel	blood goes from	blood goes to	wall
   Z	the heart	a leg muscle	thick

8. 4.

   Pia reads a card about vessel Z. Which words describe vessel Z?

   • A capillary, because it reaches the leg muscle cells
   • A vein, because it carries blood to the leg muscle
   • An artery, because blood leaves the heart through it and its wall is thick
   • A vein, because its wall is thick and has valves
9. 5.

   During the ride the leg muscles use more oxygen. On a bike ride, Ren's leg muscles use more oxygen. What happens to the vessels that bring blood to the leg muscles?

   • They stay the same width, so the flow does not change
   • They narrow, so blood moves faster to the muscles
   • They narrow, so more blood flows to the muscles
   • They widen, so more blood flows to the muscles
10. 6.

    Map (model, not to scale): the heart sends blood to two places. During a run, vessels to Tala's leg muscles widen and vessels to the digestive organs narrow. What does this do to the blood flow?

    • More blood goes to the leg muscles and less goes to the digestive organs
    • Less blood goes to both places, since the heart rate falls during a run
    • The same blood goes to both places, since the heart sends it evenly
    • More blood goes to the digestive organs and less to the leg muscles
11. 7.

    Map (model data, not to scale). Zee reads the arrows for one small vessel to a calf muscle. How many more mL of blood per minute flow when it is widened than when it is at rest?

    • 95 mL per minute
    • 25 mL per minute
    • 70 mL per minute
    • 150 mL per minute

12. Resting heart card (textbook facts)

    state	heart rate (beats per minute)	stroke volume (mL per beat)
    resting	75	70

13. 8.

    Ari reads the heart card for a person at rest. Cardiac output is heart rate times stroke volume. What is the cardiac output?

    • 525 mL per minute
    • 145 mL per minute
    • 52,500 mL per minute
    • 5,250 mL per minute

14. Alveolus oxygen card (textbook facts)

    place	oxygen (mm Hg)
    air in the alveoli	100
    blood arriving in the lung capillaries	40

15. 9.

    Bo reads the air and blood card for the lungs. According to the card, which way does oxygen move at the alveoli, and why?

    • From the blood into the air, because the blood must clear it out
    • It does not move, because oxygen needs a pump to cross
    • From the blood into the air, because the blood holds more oxygen
    • From the air into the blood, because the air holds more oxygen

16. Walk card (model data)

    state	heart rate (beats per minute)	cardiac output (mL per minute)
    walking	90	6,300

17. 10.

    Esme reads the walk card. Cardiac output is heart rate times stroke volume. What is the stroke volume?

    • 700 mL per beat
    • 70 mL per beat
    • 6,390 mL per beat
    • 7 mL per beat