The circulatory and respiratory systems working together
Grade 9 Science Worksheet - Challenge Me

Circle the best answer.
Read this first
Vessel card (textbook facts)
vessel blood goes from blood goes to oxygen in the blood W the right ventricle the lungs low X the lungs the left atrium high Y the left ventricle the body high Z the body the right atrium low Noah reads a card of four vessels, W, X, Y and Z. Using direction and oxygen together, which statement is true?
- X and Y are both arteries, because both have high oxygen
- W and Z are both veins, because both have low oxygen
- W and Y are both veins, because both leave the heart
- W and Y are both arteries, even though W has low oxygen
Lung oxygen card (textbook facts)
place oxygen (mm Hg) air in the alveoli 100 blood arriving in the lung capillaries 40 blood leaving the lungs in the pulmonary veins 100 Pia reads a card of oxygen at the lungs. Using the card and the route of blood, which statement is true?
- The lungs make oxygen that enters the blood, and the pulmonary veins carry it to the left atrium
- Oxygen diffuses into the blood at the alveoli, and the pulmonary veins carry it to the right atrium
- Oxygen diffuses into the blood at the alveoli, and the pulmonary veins carry it to the left atrium
- Oxygen diffuses into the blood at the alveoli, and the pulmonary arteries carry it to the left atrium
Run card (model data)
state heart rate (beats per minute) breathing rate (breaths per minute) resting 75 14 running 150 40 Ren reads the run card. Which statement uses both the breathing column and the heart column to explain how muscles get more oxygen?
- Faster breathing takes in more oxygen, and a faster heartbeat carries it to the muscles sooner
- A faster heartbeat brings in more oxygen, and faster breathing carries it to the muscles
- Faster breathing means the lungs make more oxygen for a faster heartbeat to carry
- A faster heartbeat sends blood from the left side to the lungs more often
Rest model card (model data)
case stroke volume (mL per beat) cardiac output (mL per minute) heart rate (beats per minute) now 70 5,250 75 changed 105 5,250 ? Tala edits a model of rest. Cardiac output stays at 5,250 mL per minute while stroke volume rises from 70 mL to 105 mL. What happens to heart rate?
- It rises to 100 beats per minute, because the heart must keep up the output
- It falls to 50 beats per minute, because each beat moves more blood
- It rises to 112 beats per minute, because a bigger beat needs a faster rhythm
- It stays at 75 beats per minute, because cardiac output did not change
Lung gradient card (model data)
time oxygen in alveolar air (mm Hg) oxygen in blood arriving (mm Hg) at rest 100 40 during a run 100 30 Zee edits a model of a run. Blood arriving at the lungs holds less oxygen than at rest. What follows at the alveoli?
- Oxygen moves into the blood faster, because the difference in oxygen is larger
- Oxygen stops moving, because the blood no longer needs any more
- Oxygen moves into the blood more slowly, because the blood has less to give
- The lungs make extra oxygen to fill the gap in the blood
Run model card (model data)
model run vessels to the leg muscles blood to the leg muscles (mL per minute) run A widen 9,000 run B narrow ? Ari edits a model of a run. In run B, vessels to the leg muscles narrow instead of widening. What does the model predict for run B?
- Less than 9,000 mL per minute, so the muscles get less oxygen
- The same 9,000 mL per minute, since the width of a vessel does not matter
- More than 9,000 mL per minute, so the muscles get more oxygen
- More than 9,000 mL per minute, since blood is squeezed through a narrow vessel
Notebook (model data)
line what it says 1 The right atrium receives oxygen-poor blood from the body 2 The right ventricle pumps blood to the lungs 3 The left atrium receives oxygen-rich blood from the lungs 4 The left ventricle pumps blood to the lungs Bo reviews a classmate's notebook on the route of blood. Exactly one line is wrong. Which line, and why?
- Line 2, because the right ventricle pumps blood to the body
- Line 4, because the left ventricle pumps blood to the body
- Line 1, because the right atrium receives blood from the lungs
- Line 3, because the left atrium receives blood from the right ventricle
Jun reviews a classmate's notebook on gas exchange. Exactly one line is wrong. Which line, and why?
- Line 3, because the lungs take oxygen from the air and do not make it
- Line 2, because diffusion moves oxygen from low amounts to high amounts
- Line 4, because carbon dioxide diffuses from the air into the blood at the alveoli
- Line 1, because the blood arriving in the lungs holds more oxygen than the air
Exercise card (model data)
state heart rate (beats per minute) stroke volume (mL per beat) cardiac output (mL per minute) resting 75 70 5,250 running 150 100 15,000 Kira reads the exercise card. Which statement does the card support?
- Cardiac output grew to more than double, because stroke volume rose as well as heart rate
- Cardiac output doubled, just like heart rate, because stroke volume did not matter
- Cardiac output stayed about the same, because the rises in rate and volume cancel
- Cardiac output grew by less than double, because stroke volume fell
Blood flow card (model data)
place at rest (mL per minute) during a run (mL per minute) leg muscles 1,200 9,000 digestive organs 1,400 300 Milo reads the blood flow card for a rest and a run. Which statement does the card support?
- During the run, the digestive organs got 1,100 mL less per minute, so their vessels widened
- During the run, the leg muscles got 7,800 mL more per minute, so their vessels widened
- During the run, the leg muscles got 7,800 mL more per minute, so their vessels narrowed
- During the run, the leg muscles got 9,000 mL more per minute, so their vessels widened