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 atrium, left ventricle, aorta, then the body
   • 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

3. 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 blood is on the arrow from the right ventricle.

4. 2.

   Kira follows blood that returned from the legs and has passed through the right atrium and right ventricle. Where does it go next?

   • Through the pulmonary arteries to the left ventricle
   • Through the pulmonary arteries to the lungs
   • Through the pulmonary veins to the lungs
   • Through the aorta to the body

5. 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.

6. 3.

   Luz follows blood from the right atrium around the whole loop and back to the right atrium. How many times does it pass through the heart?

   • Four times, once for each chamber of the heart
   • Twice, and both times on the right side of the heart
   • Once: the heart sends blood to the body and it comes back
   • Twice: once on the right side and once on the left side

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
   • A vein, because its wall is thick and has valves
   • An artery, because blood leaves the heart through it and its wall is thick
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 narrow, so more blood flows to the muscles
   • They stay the same width, so the flow does not change
   • They widen, so more blood flows to the muscles
   • They narrow, so blood moves faster 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 digestive organs and less to the leg muscles
    • The same blood goes to both places, since the heart sends it evenly
    • Less blood goes to both places, since the heart rate falls during a run
    • More blood goes to the leg muscles and less goes to the digestive organs
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
    • 150 mL per minute
    • 70 mL per minute
    • 25 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?

    • 52,500 mL per minute
    • 145 mL per minute
    • 5,250 mL per minute
    • 525 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
    • From the blood into the air, because the blood holds more oxygen
    • It does not move, because oxygen needs a pump to cross
    • 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
    • 7 mL per beat
    • 6,390 mL per beat