2. What is the primary purpose of a circulatory system? What does it transport? 3. Compare and contrast an open circulatory system of a grasshopper with a closed circulatory of an earthworm. 4. What is hemolymph? Where is it found? Why is it colorless in grasshoppers? 5. What are tracheae? Why might it be advantageous for a grasshopper to use tracheae to transport oxygen to cells? 6. Describe transport in invertebrates that have no circulatory system. 7. Describe transport in invertebrates that have a closed circulatory system. 8. List and describe the functions of the three types of vessels in a cardiovascular system. 9. What are arterioles? Do they branch into capillaries or pick up blood from capillaries? 10. What venules? Do they branch into capillaries or pick up blood from capillaries? 11. Contrast a one-circuit circulatory pathway with a two-circuit pathway. 12. Compare the circulatory system of a fish, an amphibian, and a mammal. 13. Trace the path of blood in humans from the right ventricle to the left atrium; from the left ventricle to the kidneys and to the right atrium; from the left ventricle to the small intestine and to the right atrium. 14. Contract the structure and function of the right and left ventricles. 15. Trace the path of blood through the heart from the venae cavae to the aorta. 16. Explain what happens during a heartbeat and what make the familiar lub-dub sounds. 17. What conditions might occur as a result of hypertension and plaque? 18. Describe the mechanism of a heartbeat, mentioning all of the factors that account for this repetitive process. 19. Describe how heartbeat affects blood flow. 20. Define these terms: pulmonary circuit, systemic circuit, and portal circuit.