40. Circulatory System

Which chamber(s) of a human heart receive(s) and pump(s) oxygenated blood?

Heart valves function to __________.

What is the physiological cause of a heart attack?

Blood leaves the inferior vena cava and flows directly into the __________.

Pressure is greatest in the ventricles when __________.

The SA node generates an electrical impulse from its location in __________.

A recording of the electrical activity of a patient's heart shows that the atria are contracting regularly and normally, but every few beats the ventricles fail to contract. Which of the following is probably functioning improperly?

Your blood pressure is 120/70. The "120" indicates __________, and the "70" indicates __________.

When we compare the structures and functions of arteries and veins, we find that the walls of arteries are __________, the blood pressure inside arteries is __________, and the blood in arteries is moving __________ the heart.

Which of the following decreases blood pressure?

A mutation that results in a nonfunctioning nitric oxide receptor would cause __________.

Blood pressure is highest in _________ , and blood moves most slowly in _________ . a. veins; capillaries b. arteries; capillaries c. veins; arteries d. arteries; veins

Pulse is a direct measure of a. blood pressure. b. stroke volume. c. cardiac output. d. heart rate.

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

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

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

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.

Explain why a person who survives a myocardial infarction might need to have an artificial pacemaker implanted.

During exercise, the cardiovascular system must supply muscles with large amounts of oxygen and fuel and get rid of a lot of wastes. How do the cardiovascular systems of athletes respond to prolonged exercise? Researchers used echocardiography, a sonogram of the heart, to estimate the mass of the left ventricle in current athletes, non-athletes, and ex-athletes. The data are graphed below (*** means P<0.001, and the P value comparing non-athletes and ex-athletes is >0.05). What conclusion can be drawn from the graph?

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?

During exercise, the cardiovascular system must supply muscles with large amounts of oxygen and fuel and get rid of a lot of wastes. How do the cardiovascular systems of athletes respond to prolonged exercise? Explain the advantage of the observed difference between current athletes and non-athletes in the graph shown here.

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?

During exercise, the cardiovascular system must supply muscles with large amounts of oxygen and fuel and get rid of a lot of wastes. How do the cardiovascular systems of athletes respond to prolonged exercise? Researchers have also observed that athletes and non-athletes have the same mean resting cardiac output, even though athletes have a far lower resting heart rate. How is this possible?

SCIENTIFIC THINKING 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.

During exercise, the cardiovascular system must supply muscles with large amounts of oxygen and fuel and get rid of a lot of wastes. How do the cardiovascular systems of athletes respond to prolonged exercise? Athletes are not the only people with enlarged hearts. Many patients with cardiovascular disease also have enlarged hearts. Suggest a cause of this enlargement.