Arteries, Veins and Capillaries, Circularity System & Heart 1. Where do arteries carry blood to? 2. What type of blood do they carry? 3. Why is it important that arteries have thick muscular walls with elastic fibres? 4. What is the purpose of arteries having a narrow lumen? 5. Where do veins carry blood to? 6. What type of blood do veins carry? 7. How do the inner layer of muscle and elastic fibres and the lumen differ in a vein as opposed to an artery? 8. Why is it necessary for veins to have valves? 9. What is the function of capillaries? 10. Describe the significance of capillary walls being only one cell thick and permeable. 11. How does tissue fluid aid capillaries in their function? 12. What is meant by a “double circulatory system”? 13. Describe the path of pulmonary circulation. 14. Describe the path of systemic circulation. 15. How many times does the average heart beat per minute? 16. What type of muscle is the heart made of? What characteristics of this muscle suit it to its job? 17. Why is the heart described as a “double pump”? 18. What is the cardiac conduction system (the heart’s electrical system) composed of? 19. Explain the process by which the heart is made to contract. This worksheet is provided free of charge by Porridge and Rice, a charity that supports community schools in the slums of Nairobi, the capital of Kenya. The Porridge and Rice website is at www.porridgeandrice.co.uk.