Biology · Mission: Save the Human Body
Body Fluids and Circulation
Become a doctor-in-training. Explore the blood, enter the heart, travel through blood vessels and solve an emergency by understanding how circulation works.
🎯 Blood is the transport medium. The heart is the pump. Blood vessels are the pathways. Together, they keep the body supplied and connected.
🩺 Your guide: Dr. Oliver, a young medical trainee. · Source: Plus One Biology · NCERT-aligned (14-page lesson storyboard)
⚠ Educational exercise only. Real transfusions require professional blood typing, Rh assessment and cross-matching. Do not use this simulation to make medical decisions. Blood colours in diagrams are a convention — real blood is never blue.
Levels
0/7
XP
0
Rank
Trainee
Streak
0 days
Mastered
0/17
Final
—
Mission map
- 1Level 1Blood InvestigationPlasma, RBCs, WBCs, platelets and clotting3 scenes
- 🔒Level 2Heart Control RoomFour chambers, valves and major vesselsPass Level 1 to unlock
- 🔒Level 3Blood Vessel MazeArteries, veins and capillariesPass Level 2 to unlock
- 🔒Level 4Follow the BloodThe route blood takes through the heart and lungsPass Level 3 to unlock
- 🔒Level 5Double-Circulation RacePulmonary and systemic circulationPass Level 4 to unlock
- 🔒Level 6Blood Group EmergencyABO groups, Rh factor and transfusion compatibilityPass Level 5 to unlock
- 🔒Level 7Final Doctor MissionApply concepts to real-life situationsPass Level 6 to unlock
Practice & assessment
Guided practice
Questions from levels you've unlocked, with hints.
🎯Independent practice
No hints, plus fresh engine-generated questions. Proves mastery.
🔁Revision practice
Targets your weak concepts and past mistakes.
🗣️Oral revision
Explain ideas out loud to your teacher.
🏁Final assessment
The end-of-course test. 70% to pass.
⚡Challenge mode
Harder mixed questions, no hints. Beat your best.
Badges
Concept mastery
Mastery needs repeated correct answers including at least one without help — finishing a lesson alone doesn’t count.
- Plasma and formed elementsnot started
- Jobs of RBCs, WBCs, platelets, plasmanot started
- Haemoglobin and oxygen transportnot started
- Clotting and fibrinnot started
- Four heart chambersnot started
- Heart valvesnot started
- Major blood vesselsnot started
- Arteriesnot started
- Veins and valvesnot started
- Capillaries and exchangenot started
- The complete routenot started
- Pulmonary circulationnot started
- Systemic circulationnot started
- Double circulationnot started
- ABO antigens and antibodiesnot started
- Rh factornot started
- Transfusion compatibility (educational)not started
Glossary
- Haemoglobin
- — Iron-containing protein in red blood cells that binds oxygen.
- Erythrocyte
- — Scientific name for a red blood cell.
- Leucocyte
- — Scientific name for a white blood cell.
- Thrombocyte
- — Another name used for a platelet.
- Plasma
- — Liquid component of blood.
- Antigen
- — A molecule or marker recognised by the immune system.
- Antibody
- — A protein that binds a specific antigen or target.
- Systole
- — Phase when a heart chamber contracts.
- Diastole
- — Phase when a heart chamber relaxes.
- Pulse
- — Pressure wave felt in an artery as the heart pumps.
- Blood pressure
- — Force exerted by blood against vessel walls.
- Cardiac output
- — Volume of blood pumped by one ventricle per minute.
- Lymph
- — Fluid in lymphatic vessels; returns excess tissue fluid and supports immune functions.
Accuracy notes
- Blood is a fluid connective tissue. Plasma is its liquid matrix; formed elements include RBCs, WBCs and platelets.
- Arteries carry blood away from the heart; veins carry blood towards it. Do not define them by oxygen content.
- In adult human circulation, pulmonary artery carries deoxygenated blood and pulmonary veins carry oxygenated blood.
- The left ventricle has a thicker muscular wall than the right ventricle because it pumps blood through systemic circulation.
- Blood appears red; deoxygenated blood is darker red, not blue. Blue is only a diagram convention.
- Blood transfusion decisions require blood typing, Rh assessment and cross-matching by trained professionals.
Optional extensions
- Cardiac cycle. Systole (contraction) and diastole (relaxation). The heart simulation shows atrial systole, ventricular systole and diastole with the valves opening and closing in each phase.
- ECG, heart rate and cardiac output. Cardiac output = heart rate × stroke volume (e.g. 72 beats/min × 70 mL ≈ 5 L/min). The heart simulation has a heart-rate control and computes output.
- Lymph and lymphatic circulation. Lymph returns excess tissue fluid to the blood and supports immune functions.
- Disorders. Hypertension (persistently high blood pressure), coronary artery disease (narrowed coronary arteries) and angina (chest pain when heart muscle gets too little oxygen).