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- Use the following diagram to review the flow of blood through a human cardiovascular system. Label the indicated parts, highlight the vessels that carry oxygen-rich blood, and then trace the flow of blood by numbering the circles from 1 to 10, starting with 1 in the right ventricle. (When two locations are equivalent in the pathway, such as right and left lung capillaries or capillaries of top and lower portion of the body, assign them the same number.)
Problem 1
Problem 2
Blood pressure is highest in _________ , and blood moves most slowly in _________ .
a. Veins; capillaries
b. Arteries; capillaries
c. Veins; arteries
d. Arteries; veins
Problem 3
When the doctor listened to Janet's heart, he heard 'lub-hiss, lub-hiss' instead of the normal 'lub-dup' sounds. The hiss is most likely due to _________ . (Explain your answer.)
a. A defective atrioventricular (AV) valve
b. A damaged pacemaker (SA node)
c. A defective semilunar valve
d. High blood pressure
Problem 4
Which of the following is the main difference between your cardiovascular system and that of a fish?
a. Your heart has two chambers; a fish heart has four.
b. Your circulation has two circuits; fish circulation has one.
c. Your heart chambers are called atria and ventricles.
d. Yours is a closed system; the fish's is an open system.
Problem 5
Paul's blood pressure is 150/90. The 150 indicates _________ , and the 90 indicates _________ .
a. Pressure in the left ventricle; pressure in the right ventricle
b. Pressure during ventricular contraction; pressure during heart relaxation
c. Systemic circuit pressure; pulmonary circuit pressure
d. Pressure in the arteries; pressure in the veins
Problem 6
Which of the following initiates the process of blood clotting?
a. Damage to the lining of a blood vessel
b. Conversion of fibrinogen to fibrin
c. Attraction of white blood cells to a site of infection
d. Conversion of fibrin to fibrinogen
Problem 7
Blood flows more slowly in the arterioles than in the artery that supplies them because the arterioles
a. Have thoroughfare channels to venules that are often closed off, slowing the flow of blood.
b. Have sphincters that restrict flow to capillary beds.
c. Are narrower than the artery.
d. Collectively have a larger cross-sectional area than does the artery.
Problem 8
Which of the following is not a true statement about open and closed circulatory systems?
a. Both systems have some sort of a heart that pumps a circulatory fluid through the body.
b. A frog has an open circulatory system; other vertebrates have closed circulatory systems.
c. The blood and interstitial fluid are separate in a closed system but are indistinguishable in an open system.
d. Some of the circulation of blood in both systems results from body movements.
- Trace the path of blood starting in a pulmonary vein, through the heart, and around the body, returning to the pulmonary vein. Name, in order, the heart chambers and types of vessels through which the blood passes.
Problem 9
Problem 10
If blood were supplied to all of the body's capillaries at one time,
a. Blood pressure would fall dramatically.
b. Resistance to blood flow would increase.
c. Blood would move too rapidly through the capillaries.
d. The amount of blood returning to the heart would increase.
- If a blood clot forms inside a vein in the leg, it may travel through the circulatory system. What is the first capillary bed the clot would reach, where it might block blood flow?
Problem 11
- Explain how the structure of capillaries relates to their function of exchanging substances with the surrounding interstitial fluid. Describe how that exchange occurs.
Problem 12
- Here is a blood sample that has been spun in a centrifuge. List, as completely as you can, the components you would find in the straw-colored fluid at the top of this tube and in the dense red portion at the bottom.
Problem 13
- Some babies are born with a small hole in the wall between the left and right ventricles. How might this affect the oxygen content of the blood pumped out of the heart into the systemic circuit?
Problem 14
- Juan has a disease in which damaged kidneys allow some of his normal plasma proteins to be removed from the blood. How might this condition affect the osmotic pressure of blood in capillaries, compared with that of the surrounding interstitial fluid? One of the symptoms of this kidney malfunction is an accumulation of excess interstitial fluid, which causes Juan's arms and legs to swell. Can you explain why this occurs?
Problem 15
Problem 16
The studies described in Module 23.6 were funded by both government agencies and major pharmaceutical and medical supply companies. NIH grants for research on heart disease total more than $1.2 billion per year. Gather more information and form an opinion on how heart disease research should be funded, whether by private enterprises such as pharmaceutical companies, donor-supported nonprofit organizations, or government agencies. Write an essay arguing your point of view.
- 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?
Problem 17