Campbell Biology Concepts & Connections Second Custom Edition For Tacoma Community College
8th Edition
ISBN: 9781269959810
Author: Reece
Publisher: PEARSON C
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Chapter 23, Problem 16TYK
Physiologists speculate about cardiovascular adaptations in dinosaurs—some of which had necks almost 10 m (33 feet) long. Such animals would have required a systolic pressure of nearly 760 mm Hg to pump blood to the brain when the head was fully raised. Some analyses suggest that dinosaurs’ hearts were not powerful enough to generate such pressures, leading to the speculation that long-necked dinosaurs fed close to the ground rather than raising their heads to feed on high foliage. Scientists also debate whether dinosaurs had a “reptile-like” or “bird-like” heart. Most modern reptiles have a three-chambered heart with just one ventricle. Birds, which evolved from a lineage of dinosaurs, have a four-chambered heart. Some scientists believe that the circulatory needs of these long-necked dinosaurs provide evidence that dinosaurs must have had a four-chambered heart. Why might they conclude this?
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Trace the flow of blood through a mammalian heart, naming the four chambers and their valves, and explaining where the blood entering each atrium comes from and where blood leaving each ventricle goes. When the ventricles contract, what prevents blood from reen-tering the atria? What factors cause blood to move forward at high pressure in the aorta?
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Which of the following statements about vertebrate circulatory systems is not true?
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In mammals, the blood pressure in the aorta is higher than the pressure in the pulmonary artery.
B.
In fishes, oxygenated blood from the gills returns directly to the heart through the left atrium.
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Chapter 23 Solutions
Campbell Biology Concepts & Connections Second Custom Edition For Tacoma Community College
Ch. 23 - Connecting the Concepts 1. Use the following...Ch. 23 - Prob. 2TYKCh. 23 - When the doctor listened to Janets heart, he heard...Ch. 23 - Prob. 4TYKCh. 23 - Prob. 5TYKCh. 23 - Prob. 6TYKCh. 23 - Blood flows more slowly in the arterioles than in...Ch. 23 - Which of the following is not a true statement...Ch. 23 - Prob. 9TYKCh. 23 - Trace the path of blood starting in a pulmonary...
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