Question 1

Humans infected with some types of parasitic worms develop a condition called elephantiasis, which is characterized by swelling of the limbs. Which of the following would be the most likely cause of elephantiasis?

Accepted Answer

A)   The infected human's immune system is fighting the worms.
B)   The worm infection is causing a decrease in cardiac output.
C)   The worms are blocking the lymph vessels.
D)   More blood is flowing through precapillary sphincters.E) C) and D)
F) None of the above

Question 2

Atmospheric pressure at the summit of Mount Everest is about one third the pressure at sea level, which is 760 mm Hg. If oxygen makes up 21% of the atmosphere by volume, the partial pressure of oxygen (PO₂) on Mount Everest is approximately ________.

Accepted Answer

A)   53 mm Hg
B)   157 mm Hg
C)   255 mm Hg
D)   760 mm HgE) A) and D)
F) B) and D)

Question 3

Which of the following conditions would most likely be due to high blood pressure in a mammal?

Accepted Answer

A)   bursting of blood vessels in capillary beds
B)   inability of the right ventricle to contract
C)   reversal of normal blood flow direction in arteries
D)   destruction of red blood cellsE) A) and B)
F) C) and D)

Question 4

The diagnosis of hypertension in adults is based on the ________.

Accepted Answer

A)   measurement of fatty deposits on the endothelium of arteries
B)   measurement of the LDL/HDL ratio in peripheral blood
C)   percentage of blood volume made up of platelets
D)   blood pressure being greater than 140 mm Hg systolic and/or greater than 90 mm Hg diastolicE) A) and B)
F) A) and D) D

Question 5

Atrial systole ________.

Accepted Answer

A)   occurs at the same time as ventricular diastole
B)   pumps blood to the aorta
C)   refers to the relaxation of the cardiac muscle
D)   only occurs in the left heart chambersE) B) and D)
F) A) and B)

Question 6

Small swollen areas in the neck, groin, and axillary region are associated with ________.

Accepted Answer

A)   increased activity of the immune system
B)   blood sugar that is abnormally high
C)   dehydration
D)   sodium depletionE) C) and D)
F) A) and B)

Question 7

Cyanide poisons mitochondria by blocking the final step in the electron transport chain. Human red blood cells placed in an isotonic solution containing cyanide are likely to ________.

Accepted Answer

A)   retain the normal cell shape, but the mitochondria will be poisoned
B)   lyse as the cyanide concentration increases inside the cell
C)   switch to anaerobic metabolism
D)   be unaffectedE) B) and C)
F) All of the above

Question 8

Which of the following develops the greatest pressure on the blood in the mammalian aorta?

Accepted Answer

A)   systole of the left atrium
B)   diastole of the right ventricle
C)   systole of the left ventricle
D)   diastole of the right atriumE) C) and D)
F) A) and B)

Question 9

Which of the following events would you predict as carbon dioxide is released from your muscles into the surrounding capillary bed?

Accepted Answer

A)   Oxygen delivery to muscle is increased when more carbon dioxide is produced by the muscle.
B)   Because of the change in blood pH, the blood can carry more oxygen.
C)   The amount of oxygen in venous blood will increase.
D)   Arterial blood entering the capillaries will carry more oxygen.E) B) and D)
F) A) and D)

Question 10

What would be the consequence if we were to reverse the direction of water flow over the gills of a fish, moving water inward past the operculum, past the gills, then out the mouth? This reversal of water flow would ________.

Accepted Answer

A)   reduce efficiency of gas exchange
B)   change the exchange of gases in the body from carbon dioxide out and oxygen in to carbon dioxide in and oxygen out
C)   increase the efficiency of gas exchangeD) A) and B)
E) All of the above

Question 11

Among the following choices, which organism likely has the highest systolic pressure?

Accepted Answer

A)   mouse
B)   human
C)   hippopotamus
D)   giraffeE) A) and C)
F) All of the above D

Question 12

One feature that amphibians and humans have in common is

Accepted Answer

A)   the number of heart chambers.
B)   a complete separation of circuits for circulation.
C)   the number of circuits for circulation.
D)   a low blood pressure in the systemic circuit.E) A) and C)
F) A) and D)

Question 13

Countercurrent exchange is evident in the flow of ________.

Accepted Answer

A)   water across the gills of a fish and the blood within those gills
B)   blood in the dorsal vessel of an insect and that of air within its tracheae
C)   air within the primary bronchi of a human and the blood within the pulmonary veins
D)   water across the skin of a frog and the blood flow within the ventricle of its heartE) B) and D)
F) B) and C) A

Question 14

An anthropologist discovers the fossilized heart of an extinct animal. The evidence indicates that the organism's heart was large, was well-formed, and had four chambers, with no connection between the right and left sides. A reasonable conclusion supported by these observations is that the ________.

Accepted Answer

A)   animal had evolved from birds
B)   animal was endothermic and had a high metabolic rate
C)   animal was most closely related to alligators and crocodiles
D)   species had little to no need to regulate blood pressureE) C) and D)
F) B) and C)

Question 15

Some human infants, especially those born prematurely, suffer serious respiratory failure because of ________.

Accepted Answer

A)   the sudden change from the uterine environment to the air
B)   the overproduction of surfactants
C)   lung collapse due to inadequate production of surfactant
D)   mutations in the genes involved in lung formationE) A) and B)
F) A) and C)

Question 16

Most of the carbon dioxide produced by humans is ________.

Accepted Answer

A)   converted to bicarbonate ions
B)   bound to hemoglobin
C)   transported in the erythrocytes as carbonic acid
D)   simply dissolved in the plasmaE) All of the above
F) B) and D)

Question 17

Carbon dioxide levels in the blood and cerebrospinal fluid affect pH. This enables the organism to sense a disturbance in gas levels as ________.

Accepted Answer

A)   the brain directly measures and monitors oxygen levels and causes breathing changes accordingly
B)   the medulla oblongata, which is in contact with cerebrospinal fluid, monitors pH and uses this measure to control breathing
C)   the brain alters the pH of the cerebrospinal fluid to force the animal to retain more or less carbon dioxide
D)   stretch receptors in the lungs cause the medulla oblongata to speed up or slow breathingE) B) and D)
F) A) and C)

Question 18

A decrease of blood pH from 7.4 to 7.2 causes hemoglobin to ________.

Accepted Answer

A)   release all bound carbon dioxide molecules
B)   bind more oxygen molecules
C)   decrease its binding of H⁺
D)   give up more of its oxygen moleculesE) None of the above
F) All of the above

Question 19

Blood is pumped at high pressures in arteries from the heart to ensure that all parts of the body receive adequate blood flow. Capillary beds, however, would hemorrhage under direct arterial pressures. How does the design of the circulatory network contribute to reducing blood pressure to avoid this scenario?

Accepted Answer

A)   Blood flow through the capillaries is essentially frictionless, and this reduces the amount of pressure on their walls.
B)   The total cross-sectional diameter of the arterial circulation increases with progression from artery to arteriole to capillary, leading to a reduced blood pressure.
C)   Fluid loss from the arteries is high enough that pressure drops off significantly by the time blood reaches the capillaries.
D)   Capillary beds have the thickest walls of any blood vessel to resist these high pressures.E) C) and D)
F) A) and D)

Question 20

The circulatory systems of bony fishes, rays, and sharks are most similar to ________.

Accepted Answer

A)   those of birds, with a four-chambered heart
B)   the portal systems of mammals, where two capillary beds occur sequentially, without passage of blood through a pumping chamber
C)   those of sponges, where gas exchange in all cells occurs directly with the external environment
D)   those of humans, where there are four pumping chambers to drive blood flowE) A) and B)
F) All of the above

Exam 42: Circulation and Gas Exchange

Humans infected with some types of parasitic worms develop a condition called elephantiasis, which is characterized by swelling of the limbs. Which of the following would be the most likely cause of elephantiasis?

Correct Answer
verified

Atmospheric pressure at the summit of Mount Everest is about one third the pressure at sea level, which is 760 mm Hg. If oxygen makes up 21% of the atmosphere by volume, the partial pressure of oxygen (PO₂) on Mount Everest is approximately ________.

Correct Answer
verified

Which of the following conditions would most likely be due to high blood pressure in a mammal?

Correct Answer
verified

The diagnosis of hypertension in adults is based on the ________.

Correct Answer
verified
D

Atrial systole ________.

Correct Answer
verified

Small swollen areas in the neck, groin, and axillary region are associated with ________.

Correct Answer
verified

Cyanide poisons mitochondria by blocking the final step in the electron transport chain. Human red blood cells placed in an isotonic solution containing cyanide are likely to ________.

Correct Answer
verified

Which of the following develops the greatest pressure on the blood in the mammalian aorta?

Correct Answer
verified

Which of the following events would you predict as carbon dioxide is released from your muscles into the surrounding capillary bed?

Correct Answer
verified

What would be the consequence if we were to reverse the direction of water flow over the gills of a fish, moving water inward past the operculum, past the gills, then out the mouth? This reversal of water flow would ________.

Correct Answer
verified

Among the following choices, which organism likely has the highest systolic pressure?

Correct Answer
verified
D

One feature that amphibians and humans have in common is

Correct Answer
verified

Countercurrent exchange is evident in the flow of ________.

Correct Answer
verified
A

Correct Answer
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Some human infants, especially those born prematurely, suffer serious respiratory failure because of ________.

Correct Answer
verified

Most of the carbon dioxide produced by humans is ________.

Correct Answer
verified

Carbon dioxide levels in the blood and cerebrospinal fluid affect pH. This enables the organism to sense a disturbance in gas levels as ________.

Correct Answer
verified

A decrease of blood pH from 7.4 to 7.2 causes hemoglobin to ________.

Correct Answer
verified

Correct Answer
verified

The circulatory systems of bony fishes, rays, and sharks are most similar to ________.

Correct Answer
verified

Exam 42: Circulation and Gas Exchange

Humans infected with some types of parasitic worms develop a condition called elephantiasis, which is characterized by swelling of the limbs. Which of the following would be the most likely cause of elephantiasis?

Correct AnswerverifiedShow Answer

Atmospheric pressure at the summit of Mount Everest is about one third the pressure at sea level, which is 760 mm Hg. If oxygen makes up 21% of the atmosphere by volume, the partial pressure of oxygen (PO₂) on Mount Everest is approximately ________.

Correct AnswerverifiedShow Answer

Which of the following conditions would most likely be due to high blood pressure in a mammal?

Correct AnswerverifiedShow Answer

The diagnosis of hypertension in adults is based on the ________.

Correct AnswerverifiedD

Atrial systole ________.

Correct AnswerverifiedShow Answer

Small swollen areas in the neck, groin, and axillary region are associated with ________.

Correct AnswerverifiedShow Answer

Cyanide poisons mitochondria by blocking the final step in the electron transport chain. Human red blood cells placed in an isotonic solution containing cyanide are likely to ________.

Correct AnswerverifiedShow Answer

Which of the following develops the greatest pressure on the blood in the mammalian aorta?

Correct AnswerverifiedShow Answer

Which of the following events would you predict as carbon dioxide is released from your muscles into the surrounding capillary bed?

Correct AnswerverifiedShow Answer

What would be the consequence if we were to reverse the direction of water flow over the gills of a fish, moving water inward past the operculum, past the gills, then out the mouth? This reversal of water flow would ________.

Correct AnswerverifiedShow Answer

Among the following choices, which organism likely has the highest systolic pressure?

Correct AnswerverifiedD

One feature that amphibians and humans have in common is

Correct AnswerverifiedShow Answer

Countercurrent exchange is evident in the flow of ________.

Correct AnswerverifiedA

Correct AnswerverifiedShow Answer

Some human infants, especially those born prematurely, suffer serious respiratory failure because of ________.

Correct AnswerverifiedShow Answer

Most of the carbon dioxide produced by humans is ________.

Correct AnswerverifiedShow Answer

Carbon dioxide levels in the blood and cerebrospinal fluid affect pH. This enables the organism to sense a disturbance in gas levels as ________.

Correct AnswerverifiedShow Answer

A decrease of blood pH from 7.4 to 7.2 causes hemoglobin to ________.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

The circulatory systems of bony fishes, rays, and sharks are most similar to ________.

Correct AnswerverifiedShow Answer

Correct Answer
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D

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D

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A

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