Study guide questions: Chapter 42:
Important terms: Cardiac cycle, systole, diastole, cardiac output, heart rate, stroke volume, heart murmur (page 903); the sinoatrial (SA) node (pace maker) (page 904); vasoconstriction, vasodilation (page 907); hemoglobin (page 911, also 924), heart attack, stroke, hypertension, etherosclerosis (pages 913-915).
1. Distinguish between a) open and closed circulatory systems; b) single and double circulation; c) pulmonary and systemic circuits (Pages 889-901).
2. Coordinated cycles of heart contraction drive double circulation in mammals. De-oxygenated blood from the body enters the heart, which is then pumped to the lung to be oxygenated. The newly oxygenated blood enters the heart and then pumped to the whole body. Use the structures given below to describe the direction of ...view middle of the document...
Label the figure given below (page 903, Fig 42.7).
5. In vertebrates, the heartbeat originates in the heart itself. What maintains the heart’s rhythmic beat? Why is it important that the AV node delay an electrical impulse moving from the SA node and the atria to the ventricles? Why is it that the hearts tempo changes under different circumstances, for example when we sit and relax, when we walk, when we have fever? (Page 904).
6. Contracting ventricles put pressure on the blood, forcing it through a series of vessels: arteries, arterioles, capillaries, venules and veins. - The walls of which of the five structures is thicker and stronger? Why (Page 905, also Fig 42.10). - Which of the structures have the lowest blood velocity? Why? - Which of the structures have the highest blood pressure? Why? Which of the structures have valves? (Page 906, also Fig 42.11).
7. Cellular elements comprise 45% of the blood volume. List the cellular elements of the blood and their functions. Which ones lack nucleus and mitochondria? (Pages 911, also Fig 42.17).
8. Why is it advantageous for animals to have a moist, thin and large surface area for their respiratory surfaces? (Page 916). Why is the position of the lung tissues within the body an advantage for terrestrial animals?
9. Label the structures denoted by A-K, in the figure given below. Briefly describe the functions of each of these structures. Trace the route of air into the human lungs in a correct order through these structures.(Page 918-919, Fig 42.25)
10. Gas exchange in mammals in __________. Where are the alveoli located? Why don’t alveoli collapse? (Page 919-920).
11. How the brain (medulla oblongata) controls the rate and depth of breathings? (Page 922, also Fig 42.29).
12. Answer questions 1-7, on page 928. Answers are given in appendix A.