Exam 50: Circulatory Systems

The complexity and number of chambers in the heart increases from fishes to amphibians to reptiles to mammals and birds. An important consequence of this increased complexity is the gradual separation of the circulatory system into two independent circuits: the _______ and the _______.

The production of erythrocytes

Gap junctions

During the cardiac cycle, the blood pressure in the aorta is at a minimum

Which of the following is present in veins, but not arteries?

Which of the following statements about vertebrate circulatory systems is false?

The walls of large _______ have elastic fibers and can withstand high pressures.

Refer to the graph below, which depicts blood pressure, blood velocity, and the area of the blood vessels throughout a circulatory system. Which of the following statements is false?

The blood vessels with the greatest total cross-sectional area are the

Crocodilians differ from other reptiles in that they have

Which of the following hormones causes constriction of the blood vessels?

Which of the following is an example of an animal with an open circulatory system?

A platelet is activated to initiate clotting

Which of the following statements about the control of circulation in humans is false?

As compared to the circulatory system of most fishes, the circulatory system of adult amphibians has the advantage of

The primary pacemaker of the heart is the _______ at the junction of the superior vena cava and right atrium.

Blood consists of a fluid fraction consisting of _______ and a solid fraction consisting of _______.

Some large, multicellular, aquatic animals have no circulatory system. They manage gas exchange

Which of the following does not control the cardiac cycle?

Which statement about the human heart is true?