3.2 Transport

• Importance of transport in animals
• Transport systems in insects, fish, amphibians, reptiles and mammals
• Structure and pumping mechanism of the mammalian heart
• The lymphatic and immune systems, and blood clotting
• ABO and rhesus blood grouping

• explain the importance of transport in animals
• illustrate the structure of transport systems in different animal groups
• describe the pumping mechanism of the mammalian heart
• describe the human lymphatic and immune systems, and blood clotting
• explain the ABO and rhesus factor blood grouping systems

“Why do larger animals need a transport system when small ones do not?”

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1. Transport systems and the heart
   40 min · 2 practice tasks · quiz
   Why size demands a circulation, and how the mammalian heart pumps.
2. Blood, immunity and blood groups
   40 min · 2 practice tasks · quiz
   What blood carries, how the body defends itself, and why transfusions must match.
3. Why animals need a transport system
   40 min · 1 practice tasks · quiz
   Diffusion works over a few cells. A cow, a tilapia and a human all need a pump because volume outgrows surface.
4. Open and closed circulation
   40 min · 1 practice tasks · quiz
   Insects bathe organs in haemolymph. Vertebrates keep blood inside vessels so pressure stays high.
5. Single circulation in fish
   40 min · 1 practice tasks · quiz
   A two-chambered heart pumps once around a single circuit: heart, gills, body, heart.
6. Hearts of amphibians and reptiles
   40 min · 1 practice tasks · quiz
   Three chambers mean some mixing. A partial septum, and the crocodile exception, show the path towards a four-chambered heart.
7. Structure of the mammalian heart
   40 min · 1 practice tasks · quiz
   Four chambers, four valves, a septum, and named great vessels - the pump that the overview lesson only sketched.
8. The cardiac cycle and the heartbeat
   40 min · 1 practice tasks · quiz
   SAN, AV delay, systole, diastole, lub-dub, and a pulse you can count on the wrist.
9. Arteries, veins and capillaries
   40 min · 1 practice tasks · quiz
   Three vessel types, three jobs: withstand pressure, return a large volume, and exchange.
10. Double circulation in mammals
    40 min · 1 practice tasks · quiz
    Pulmonary and systemic circuits, plus coronary and hepatic portal routes - why two pumps beat one.
11. Plasma and red blood cells
    40 min · 1 practice tasks · quiz
    Blood is a tissue: straw-coloured plasma plus biconcave cells packed with haemoglobin.
12. White cells and immunity
    40 min · 1 practice tasks · quiz
    Phagocytes engulf; lymphocytes make antibodies and memory. Vaccination borrows that memory.
13. The lymphatic system and blood clotting
    40 min · 1 practice tasks · quiz
    Tissue fluid that does not return to the capillary becomes lymph. A clot is fibrin mesh plus trapped red cells.
14. ABO, rhesus and blood donation
    40 min · 1 practice tasks · quiz
    Match donor antigens to recipient antibodies. O cells travel widely; O people cannot receive widely. Donate if you can.