Question 1

What will be the long-term effect of blocking the lymphatic vessels associated with a capillary bed?

Accepted Answer

A)   more fluid entering the venous capillaries
B)   an increase in the blood pressure in the capillary bed
C)   the accumulation of more fluid in the interstitial areas
D)   fewer proteins leaking out of the blood to enter the interstitial fluid
E)   the area of the blockage becoming abnormally small

Question 2

In a healthy human, the typical life span of a red blood cell is

Accepted Answer

A)   24 hours.
B)   one week.
C)   one month.
D)   four months.
E)   80 years or more.

Question 3

Air-breathing insects carry out gas exchange

Accepted Answer

A)   in their specialized external gills.
B)   in their specialized internal gills.
C)   in the alveoli of their lungs.
D)   across the membranes of their cells.
E)   across all parts of their thin cuticular exoskeleton.

Question 4

At sea level, atmospheric pressure is 760 mm Hg. Oxygen gas is approximately 21% of the total gases in the atmosphere, so the approximate partial pressure of oxygen is

Accepted Answer

A)   0.2 mm Hg.
B)   20.0 mm Hg.
C)   76.0 mm Hg.
D)   160.0 mm Hg.
E)   508.0 mm Hg.

Question 5

Most of the carbon dioxide produced by humans is

Accepted Answer

A)   converted to bicarbonate ions by an enzyme in red blood cells.
B)   bound to hemoglobin.
C)   transported in the erythrocytes as carbonic acid.
D)   simply dissolved in the plasma.
E)   bicarbonate ions bound to hemoglobin.

Question 6

Countercurrent exchange is evident in

Accepted Answer

A)   the flow of water across the gills of a fish and that of blood within those gills.
B)   the flow of blood in the dorsal vessel of an insect and that of air within its tracheae.
C)   the flow of air within the primary bronchi of a human and that of blood within the pulmonary veins.
D)   the flow of water across the skin of a frog and that of blood within the ventricle of its heart.
E)   the flow of fluid out of the arterial end of a capillary and that of fluid back into the venous end of the same capillary.

Question 7

Flying insects do all of the following except

Accepted Answer

A)   increase metabolism as much as 200-fold during flight.
B)   switch from diffusion of tracheal gases to active transport during flight.
C)   utilize high numbers of mitochondria in flight muscles.
D)   produce water molecules from oxygen in mitochondria.
E)   generate carbon dioxide from catabolism of fuel molecules.

Question 8

Breathing is usually regulated by

Accepted Answer

A)   erythropoietin levels in the blood.
B)   the concentration of red blood cells.
C)   hemoglobin levels in the blood.
D)   CO₂ and O₂ concentration and pH-level sensors.
E)   the lungs and the larynx.

Question 9

Dialysis patients, who will have blood withdrawn, dialyzed, then replaced, are always weighed when they enter the facility and then weighed carefully again before they leave, because

Accepted Answer

A)   even small changes in body weight may signify changes in blood volume and therefore blood pressure.
B)   many people who have dialysis are diabetic and must control their weight carefully.
C)   dialysis removes blood proteins and these weigh more than other blood components.
D)   dialysis is likely to cause edema and such swelling must be controlled.
E)   reclining posture during dialysis can cause a tendency for weight gain.

Question 10

During most daily activities, the human respiration rate is most closely linked to the blood levels of

Accepted Answer

A)   nitric acid.
B)   nitrogen.
C)   oxygen.
D)   carbon dioxide.
E)   carbon monoxide.

Question 11

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)   percent of blood volume made up of platelets.
D)   blood pressure being greater than 140 mm Hg systolic and/or >90 diastolic.
E)   number of leukocytes per mm³ of blood.

Question 12

Gas exchange is more difficult for aquatic animals with gills than for terrestrial animals with lungs because

Accepted Answer

A)   water is less dense than air.
B)   water contains much less O₂ than air per unit volume.
C)   gills have less surface area than lungs.
D)   gills allow only unidirectional transport.
E)   gills allow water to flow in one direction.

Question 13

A person with a tidal volume of 450 mL, a vital capacity of 4,000 mL, and a residual volume of 1,000 mL would have a potential total lung capacity of

Accepted Answer

A)   1,450 mL.
B)   4,000 mL.
C)   4,450 mL.
D)   5,000 mL.
E)   5,450 mL.

Question 14

At the summit of a high mountain, the atmospheric pressure is 380 mm Hg. If the atmosphere is still composed of 21% oxygen, then the partial pressure of oxygen at this altitude is

Accepted Answer

A)   0 mm Hg.
B)   80 mm Hg.
C)   160 mm Hg.
D)   380 mm Hg.
E)   760 mm Hg.

Question 15

The sun shining on a tidal pool during a hot day heats the water. As some water evaporates, the pool becomes saltier, causing

Accepted Answer

A)   a decrease in its carbon dioxide content.
B)   a decrease in its oxygen content.
C)   an increase in its ability to sustain aerobic organisms.
D)   a decrease in the water's density.
E)   a decrease in the movement of the water molecules.

Question 16

In an animal species known for endurance running rather than fast sprinting, you would expect to find

Accepted Answer

A)   a slower rate of oxygen consumption so that its breathing will not have to be accelerated.
B)   an increase of storage of oxygen in myoglobin of its muscles.
C)   a relatively slow heart rate in order to lower oxygen consumption.
D)   a lower pressure of oxygen in the alveoli.
E)   a much higher rate of oxygen consumption for its size.

Question 17

The set of blood vessels with the lowest blood pressure driving flow is

Accepted Answer

A)   the arteries.
B)   the arterioles.
C)   the metarterioles.
D)   the capillaries.
E)   the veins.

Question 18

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)   become unable to carry oxygen.
E)   be unaffected.

Question 19

The meshwork that forms the fabric of a blood clot is

Accepted Answer

A)   chymotrypsin.
B)   fibrin.
C)   thrombin.
D)   prothrombin.
E)   collagen.

Question 20

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

Accepted Answer

A)   the brain directly measures and monitors carbon dioxide 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 breathing.
E)   the medulla oblongata is able to control the concentration of bicarbonate ions in the blood.

Exam 42: Circulation and Gas Exchange

At the summit of a high mountain, the atmospheric pressure is 380 mm Hg. If the atmosphere is still composed of 21% oxygen, then the partial pressure of oxygen at this altitude is

Correct AnswerverifiedShow Answer

Flying insects do all of the following except

Correct AnswerverifiedShow Answer

The diagnosis of hypertension in adults is based on the

Correct AnswerverifiedShow Answer

In an animal species known for endurance running rather than fast sprinting, you would expect to find

Correct AnswerverifiedShow Answer

At sea level, atmospheric pressure is 760 mm Hg. Oxygen gas is approximately 21% of the total gases in the atmosphere, so the approximate partial pressure of oxygen is

Correct AnswerverifiedShow Answer

Air-breathing insects carry out gas exchange

Correct AnswerverifiedShow Answer

Most of the carbon dioxide produced by humans is

Correct AnswerverifiedShow Answer

During most daily activities, the human respiration rate is most closely linked to the blood levels of

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

In a healthy human, the typical life span of a red blood cell is

Correct AnswerverifiedShow Answer

Countercurrent exchange is evident in

Correct AnswerverifiedShow Answer

What will be the long-term effect of blocking the lymphatic vessels associated with a capillary bed?

Correct AnswerverifiedShow Answer

The set of blood vessels with the lowest blood pressure driving flow is

Correct AnswerverifiedShow Answer

Gas exchange is more difficult for aquatic animals with gills than for terrestrial animals with lungs because

Correct AnswerverifiedShow Answer

The sun shining on a tidal pool during a hot day heats the water. As some water evaporates, the pool becomes saltier, causing

Correct AnswerverifiedShow Answer

The meshwork that forms the fabric of a blood clot is

Correct AnswerverifiedShow Answer

A person with a tidal volume of 450 mL, a vital capacity of 4,000 mL, and a residual volume of 1,000 mL would have a potential total lung capacity of

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Breathing is usually regulated by

Correct AnswerverifiedShow Answer

Dialysis patients, who will have blood withdrawn, dialyzed, then replaced, are always weighed when they enter the facility and then weighed carefully again before they leave, because

Correct AnswerverifiedShow Answer

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