❤️ Circulatory System

Chapter: Human Body Systems · Level ★★☆ · Time: 25 min

SCORE___ / 20

NameClassDate

After this worksheet you can

Name heart chambers/valvesCalculate cardiac outputCompare blood vessel typesExplain the Bohr effect

📚 Quick Recap

🎯 What you'll practice: Heart structure, the cardiac cycle, blood vessels, and cardiac output calculations.

🧮 Section B · Problem Solving ● INTERMEDIATE 2 + 3×3 = 11

5Blood is 55% and 45% red blood cells.

6Veins contain to prevent backflow.

7A heart beats at 80 bpm with a stroke volume of 65 mL. Calculate cardiac output.

8Name the four heart valves.

9What does the Bohr effect describe?

🚀 Section C · Challenge ● CHALLENGE 5

10Explain why the Bohr effect is physiologically useful — why should haemoglobin release more oxygen exactly where CO2 is high?

💭 Reflection — the most useful thing I learned:

A ___/4 B ___/11 C ___/5 Total ___/20 Teacher's Signature Parent's Signature

✂ answer key — fold or cut before handing out

1-B 2-B 3-B 4-C | 5 = plasma 6 = valves 7 = CO = 80 × 65 = 5200 mL/min (5.2 L/min) 8 = bicuspid (mitral), tricuspid, aortic semilunar, pulmonary semilunar 9 = rising CO2 lowers blood pH, which reduces haemoglobin's oxygen affinity and promotes oxygen release to tissues | 10 = High CO2 concentration signals a tissue that is metabolically active and consuming oxygen quickly (e.g. exercising muscle); by releasing more oxygen exactly where CO2 (and thus lower pH) is highest, haemoglobin automatically delivers extra oxygen to the tissues that need it most, without requiring any separate signalling mechanism — a built-in feedback loop matching oxygen delivery to demand.

📄 Need offline practice?Print this worksheet or open the one-page cheat sheet.

🗒 Cheat Sheet

🧠 Section A · Concept Check ● BEGINNER 4 × 1 = 4

🧮 Section B · Problem Solving ● INTERMEDIATE 2 + 3×3 = 11

🚀 Section C · Challenge ● CHALLENGE 5