Question 1

In a healthy person at rest, the air reaching the alveoli with each breath contains about _______ ml of fresh air diluted by about _______ ml of stale air.

Accepted Answer

A)  200; 100 
B)  500; 200 
C)  500; 2000 
D)  2000; 500 
E)  5000; 200 
A)  200; 100 
B)  500; 200 
C)  500; 2000 
D)  2000; 500 
E)  5000; 200

Question 2

Refer to the figure.   As global climate change warms the air and water, which organism(s) will be using a respiratory exchange medium with decreasing amounts of oxygen?

Accepted Answer

A)  A only 
B)  A and C 
C)  A, C, and D 
D)  B only 
E)  B and E 
A)  A only 
B)  A and C 
C)  A, C, and D 
D)  B only 
E)  B and E

Question 3

Which statement about the mechanics of ventilation in humans is true?

Accepted Answer

A)  If the pleural cavity is punctured, the lung will overinflate. 
B)  As the diaphragm contracts, air is expelled from the respiratory system. 
C)  As the diaphragm contracts, pressure within the pleural cavity increases. 
D)  Less energy is expended during the exhalation phase than during the inhalation phase. 
E)  There is a slight positive pressure within the pleural cavity between breaths. 
A)  If the pleural cavity is punctured, the lung will overinflate. 
B)  As the diaphragm contracts, air is expelled from the respiratory system. 
C)  As the diaphragm contracts, pressure within the pleural cavity increases. 
D)  Less energy is expended during the exhalation phase than during the inhalation phase. 
E)  There is a slight positive pressure within the pleural cavity between breaths.

Question 4

The alveoli of the lungs do not contain air with 20.9% O2 (i.e., the percentage in dry air) because

Accepted Answer

A)  we normally do not ventilate our lungs at a high enough rate. 
B)  the lungs have too many alveoli to ventilate. 
C)  there is dead space in the trachea, bronchi, and lungs. 
D)  the trachea and bronchi are too small in volume to contain this amount of O2. 
E)  some O2 has been exchanged before reaching the alveoli. 
A)  we normally do not ventilate our lungs at a high enough rate. 
B)  the lungs have too many alveoli to ventilate. 
C)  there is dead space in the trachea, bronchi, and lungs. 
D)  the trachea and bronchi are too small in volume to contain this amount of O2. 
E)  some O2 has been exchanged before reaching the alveoli.

Question 5

Tidal breathing decreases the efficiency of gas exchange in organisms such as mammals for a number of reasons.Which is not one of those reasons?

Accepted Answer

A)  The absence of countercurrent gas exchange 
B)  The existence of dead space in the airways 
C)  The residual volume of the lungs 
D)  A short diffusion path length 
E)  The limit in the O2 concentration gradient between air and blood 
A)  The absence of countercurrent gas exchange 
B)  The existence of dead space in the airways 
C)  The residual volume of the lungs 
D)  A short diffusion path length 
E)  The limit in the O2 concentration gradient between air and blood

Question 6

Refer to the figure.   Match the curves with what they represent from the following list: fetal hemoglobin, adult hemoglobin at pH 7.4, adult hemoglobin at pH 7.2, and myoglobin.Which curve could also represent adult hemoglobin with increased 2,3-bisphosphoglycerate (BPG), a metabolite of glycolysis?

Accepted Answer

A-myoglobin; B-fetal hemoglobi

Question 7

Refer to the figure showing how carbon dioxide is transported in the blood.   In this capillary in the lung, the enzyme labeled A is _______.

Accepted Answer

The answer of Refer to the figure showing how carbon...

Question 8

Which feature characterizes CO2?

Accepted Answer

A)  PCO2 in blood capillaries is higher than that of body tissue. 
B)  It is a metabolic waste product. 
C)  It is insoluble. 
D)  PCO2 in blood capillaries is lower than that of alveoli. 
E)  It does not diffuse through cell membranes. 
A)  PCO2 in blood capillaries is higher than that of body tissue. 
B)  It is a metabolic waste product. 
C)  It is insoluble. 
D)  PCO2 in blood capillaries is lower than that of alveoli. 
E)  It does not diffuse through cell membranes.

Question 9

The breathing center in humans initiates ventilation in response to

Accepted Answer

A)  a decrease in air pressure. 
B)  an increase in O2. 
C)  an increase in CO2. 
D)  the time since the last breath. 
E)  the rate of gas exchange in the alveoli. 
A)  a decrease in air pressure. 
B)  an increase in O2. 
C)  an increase in CO2. 
D)  the time since the last breath. 
E)  the rate of gas exchange in the alveoli.

Question 10

Nodes that are sensitive to O2 and blood pressure levels are located on the

Accepted Answer

A)  aorta and carotid arteries. 
B)  brainstem capillaries. 
C)  hypothalamus. 
D)  pulmonary artery. 
E)  pulmonary vein. 
A)  aorta and carotid arteries. 
B)  brainstem capillaries. 
C)  hypothalamus. 
D)  pulmonary artery. 
E)  pulmonary vein.

Question 11

Which feature characterizes partial pressure gradients?

Accepted Answer

A)  They drive diffusion across gas exchange surfaces. 
B)  They are represented by L in Fick's law of diffusion. 
C)  They are minimized when diffusion is across thin respiratory membranes. 
D)  They are decreased by ventilation. 
E)  Greater gradients produce lower rates of gas exchange. 
A)  They drive diffusion across gas exchange surfaces. 
B)  They are represented by L in Fick's law of diffusion. 
C)  They are minimized when diffusion is across thin respiratory membranes. 
D)  They are decreased by ventilation. 
E)  Greater gradients produce lower rates of gas exchange.

Question 12

Which statement characterizes mucus in the mammalian respiratory system?

Accepted Answer

A)  The mucus escalator interferes with gas exchange. 
B)  It improves perfusion. 
C)  It clogs the respiratory tract when smoking over-stimulates ciliary action. 
D)  It is swept by downward beating cilia to the stomach for digesting. 
E)  It captures inhaled dirt and microorganisms. 
A)  The mucus escalator interferes with gas exchange. 
B)  It improves perfusion. 
C)  It clogs the respiratory tract when smoking over-stimulates ciliary action. 
D)  It is swept by downward beating cilia to the stomach for digesting. 
E)  It captures inhaled dirt and microorganisms.

Question 13

Hemoglobin delivers O2 to body cells from the red blood cells

Accepted Answer

A)  until the hemoglobin is depleted of O2. 
B)  until the partial pressures of O2 in the two different cells are equivalent. 
C)  although the hemoglobin is never completely saturated. 
D)  by releasing O2 to cells with a higher partial pressure of oxygen. 
E)  until the fluid pressure in the red blood cells is lower. 
A)  until the hemoglobin is depleted of O2. 
B)  until the partial pressures of O2 in the two different cells are equivalent. 
C)  although the hemoglobin is never completely saturated. 
D)  by releasing O2 to cells with a higher partial pressure of oxygen. 
E)  until the fluid pressure in the red blood cells is lower.

Question 14

Choose the order that accurately reflects how increasing amounts of CO2 are transported.

Accepted Answer

A)  Carried by hemoglobin; converted to HCO3- and dissolved in plasma; in solution in blood plasma 
B)  In solution in blood plasma; converted to HCO3-, which is dissolved in plasma; carried by hemoglobin 
C)  In solution in blood plasma; carried by hemoglobin; converted to HCO3-, which is dissolved in plasma 
D)  Converted to HCO3-, which is dissolved in plasma; in solution in blood plasma; carried by hemoglobin 
E)  Converted to HCO3-, which is dissolved in plasma; carried by hemoglobin; in solution in blood plasma 
A)  Carried by hemoglobin; converted to HCO3- and dissolved in plasma; in solution in blood plasma 
B)  In solution in blood plasma; converted to HCO3-, which is dissolved in plasma; carried by hemoglobin 
C)  In solution in blood plasma; carried by hemoglobin; converted to HCO3-, which is dissolved in plasma 
D)  Converted to HCO3-, which is dissolved in plasma; in solution in blood plasma; carried by hemoglobin 
E)  Converted to HCO3-, which is dissolved in plasma; carried by hemoglobin; in solution in blood plasma

Question 15

The lungs expand during an inhalation because

Accepted Answer

A)  the diaphragm contracts upward. 
B)  the shoulder girdle moves upward. 
C)  the volume of the thoracic cavity increases. 
D)  lung tissue actively stretches. 
E)  the lung tissue rebounds from exhalation. 
A)  the diaphragm contracts upward. 
B)  the shoulder girdle moves upward. 
C)  the volume of the thoracic cavity increases. 
D)  lung tissue actively stretches. 
E)  the lung tissue rebounds from exhalation.

Question 16

Smoking can lead to emphysema, a condition in which the walls of the alveoli break down, leading to fewer and larger alveoli.This causes an increase in residual volume.What is a consequence of increased residual volume?

Accepted Answer

Increased residual volume (dead space) i

Question 17

For air breathers, the partial pressure gradient for O2 _______ with increasing altitude, and the partial pressure gradient for CO2 _______.

Accepted Answer

A)  increases; decreases 
B)  increases; changes little 
C)  decreases dramatically; changes little 
D)  decreases slightly; decreases dramatically 
E)  decreases slightly; increases dramatically 
A)  increases; decreases 
B)  increases; changes little 
C)  decreases dramatically; changes little 
D)  decreases slightly; decreases dramatically 
E)  decreases slightly; increases dramatically

Question 18

In which of these PO2 environments would hemoglobin release its O2 most readily?

Accepted Answer

A)  30 mm Hg 
B)  50 mm Hg 
C)  70 mm Hg 
D)  90 mm Hg 
E)  110 mm Hg 
A)  30 mm Hg 
B)  50 mm Hg 
C)  70 mm Hg 
D)  90 mm Hg 
E)  110 mm Hg

Question 19

If a mouse carries a mutation that causes the enzyme carbonic anhydrase to be less effective, it would be reasonable to predict that the mouse would differ from a wild-type mouse in being

Accepted Answer

A)  less effective at loading CO2 from its cells to its blood, but just as effective at off-loading CO2 from the blood to the alveoli in the lungs. 
B)  less effective at off-loading CO2 from the blood to the alveoli in the lungs, but just as effective at loading CO2 from its cells to its blood. 
C)  less effective at loading CO2 from its cells to its blood and off-loading it in the alveoli in the lungs. 
D)  more effective at loading CO2 from its cells to its blood, but less effective at off-loading CO2 from the blood to the alveoli in the lungs. 
E)  more effective at off-loading CO2 from the blood to the alveoli in the lungs, but less effective at loading CO2 from its cells to its blood. 
A)  less effective at loading CO2 from its cells to its blood, but just as effective at off-loading CO2 from the blood to the alveoli in the lungs. 
B)  less effective at off-loading CO2 from the blood to the alveoli in the lungs, but just as effective at loading CO2 from its cells to its blood. 
C)  less effective at loading CO2 from its cells to its blood and off-loading it in the alveoli in the lungs. 
D)  more effective at loading CO2 from its cells to its blood, but less effective at off-loading CO2 from the blood to the alveoli in the lungs. 
E)  more effective at off-loading CO2 from the blood to the alveoli in the lungs, but less effective at loading CO2 from its cells to its blood.

Question 20

Breathing provides the body with the oxygen required to support the energy metabolism of all cells and also eliminates _______, one of the waste products of cell metabolism.

Accepted Answer

A)  carbon dioxide 
B)  carbon monoxide 
C)  carbon tetrachloride 
D)  calcium carbonate 
E)  carbonic acid 
A)  carbon dioxide 
B)  carbon monoxide 
C)  carbon tetrachloride 
D)  calcium carbonate 
E)  carbonic acid

Exam 48: Gas Exchange

In a healthy person at rest, the air reaching the alveoli with each breath contains about _______ ml of fresh air diluted by about _______ ml of stale air.

Refer to the figure. As global climate change warms the air and water, which organism(s) will be using a respiratory exchange medium with decreasing amounts of oxygen?

Which statement about the mechanics of ventilation in humans is true?

The alveoli of the lungs do not contain air with 20.9% O2 (i.e., the percentage in dry air) because

Tidal breathing decreases the efficiency of gas exchange in organisms such as mammals for a number of reasons.Which is not one of those reasons?

Refer to the figure. Match the curves with what they represent from the following list: fetal hemoglobin, adult hemoglobin at pH 7.4, adult hemoglobin at pH 7.2, and myoglobin.Which curve could also represent adult hemoglobin with increased 2,3-bisphosphoglycerate (BPG), a metabolite of glycolysis?

Refer to the figure showing how carbon dioxide is transported in the blood. In this capillary in the lung, the enzyme labeled A is _______.

Which feature characterizes CO2?

The breathing center in humans initiates ventilation in response to

Nodes that are sensitive to O2 and blood pressure levels are located on the

Which feature characterizes partial pressure gradients?

Which statement characterizes mucus in the mammalian respiratory system?

Hemoglobin delivers O2 to body cells from the red blood cells

Choose the order that accurately reflects how increasing amounts of CO2 are transported.

The lungs expand during an inhalation because

Smoking can lead to emphysema, a condition in which the walls of the alveoli break down, leading to fewer and larger alveoli.This causes an increase in residual volume.What is a consequence of increased residual volume?

For air breathers, the partial pressure gradient for O2 _______ with increasing altitude, and the partial pressure gradient for CO2 _______.

In which of these PO2 environments would hemoglobin release its O2 most readily?

If a mouse carries a mutation that causes the enzyme carbonic anhydrase to be less effective, it would be reasonable to predict that the mouse would differ from a wild-type mouse in being

Breathing provides the body with the oxygen required to support the energy metabolism of all cells and also eliminates _______, one of the waste products of cell metabolism.

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In a healthy person at rest, the air reaching the alveoli with each breath contains about _ ml of fresh air diluted by about _ ml of stale air.

The alveoli of the lungs do not contain air with 20.9% O₂ (i.e., the percentage in dry air) because

Which feature characterizes CO₂?

Nodes that are sensitive to O₂ and blood pressure levels are located on the

Hemoglobin delivers O₂ to body cells from the red blood cells

Choose the order that accurately reflects how increasing amounts of CO₂ are transported.

For air breathers, the partial pressure gradient for O₂ _ with increasing altitude, and the partial pressure gradient for CO₂ _.

In which of these PO₂ environments would hemoglobin release its O₂ most readily?