Objective 99:

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2

3

4

5

6

7

8

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Objective 100:

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Fig. 20-12a. Conducting

system of the heart

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Fig. 20-13. Sequence of impulse conduction through the heart.

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Fig. 20-4b. Direction of ventricular fibers twists the heart during contraction.

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Objective 101:

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Fig. 21-2. Elastic and muscular arteries

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Fig. 21-5. Arterioles and capillary bed

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Fig. 21-2. Venules and veins

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Objective 102:

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Fig. 21-6. Valves in the veins

promote blood flow back to the heart.

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