Question 1

Refer to the graph. When you are exercising hard, you are producing more CO₂ in your muscles than you are when resting.This causes a shift in the oxygen-binding/dissociation curve of your hemoglobin, with the new curve looking like the curve labeled _______ in the graph.

Accepted Answer

The answer of Refer to the graph.  When you...

Question 2

Air is about 78% nitrogen, and atmospheric pressure is about 760 mm Hg at sea level.The partial pressure of nitrogen at sea level is about _______ mm Hg.

Accepted Answer

The answer of Air is about 78% nitrogen, and atmospheric...

Question 3

_______ is a condition in which respiratory problems result from inflammation that destroys the alveoli and leads to large, but few, alveoli.It is caused primarily by smoking and is a leading cause of death in the United States.

Accepted Answer

The answer of _______ is a condition in which respiratory...

Question 4

Which statement about gill ventilation in fishes is false?

Accepted Answer

A)  In some species, gill ventilation occurs via open-mouth swimming. 
B)  In most species, gill ventilation occurs via a two-pump mechanism. 
C)  During an expiration by a fish using the two-pump mechanism, the mouth cavity contracts, forcing water over the gills. 
D)  During an inspiration by a fish using the two-pump mechanism, the opercular cavity expands and the opercular flaps are kept closed. 
E)  Tunas use the two-pump mechanism.

Question 5

Electrophysiological recordings are made to determine the activity of respiratory motor neurons from a patient's medulla.The recordings show that the respiratory motor neurons from the dorsal medulla are functioning normally, but those from the ventral medulla have lower than normal activity.Which is the patient's most likely symptom?

Accepted Answer

A)  His diaphragm functions normally during breathing, but he is unable to breathe deeply enough for intense physical exercise. 
B)  His breathing is compromised when at rest and he needs to be on a respirator because his diaphragm does not contract. 
C)  His lungs are unable to expand into an expanding thoracic cavity during breathing. 
D)  His lungs are unable to contract adequately after they have filled with air. 
E)  He is able to inhale deeply but is unable to exhale deeply.

Question 6

One reason rapid gas exchange can be accomplished more easily in air than in water is that

Accepted Answer

A)  the O2 content of water is higher than that of air. 
B)  the CO2 content of water is higher than that of air. 
C)  O2 diffuses more rapidly in water than in air. 
D)  water is more dense and viscous than air. 
E)  more energy is required to move air than to move water.

Question 7

If you climb a mountain to an altitude where the PO2 is half of what it is at sea level, it is likely that

Accepted Answer

A)  the decreased acidity of your blood and cerebral spinal fluid caused by the low PO2 will cause you to breathe more rapidly. 
B)  feedback from your carotid bodies and aortic bodies to your medulla will increase your breathing rate. 
C)  you will be unable to sense the change in the PO2 in your blood, since your body is only sensitive to changes in PCO2 in your blood. 
D)  the increased acidity of your blood and cerebral spinal fluid caused by the high PCO2 in the atmosphere will increase your breathing rate. 
E)  your hemoglobin will become saturated with oxygen but unable to release it in your tissues.

Question 8

By converting CO2 to H2CO3, carbonic anhydrase _______the PCO2 in endothelial cells, red blood cells, and plasma, thereby _______ diffusion of CO2 from tissue cells to these locations.

Accepted Answer

A)  reduces; facilitating 
B)  increases; facilitating 
C)  reduces; stabilizing 
D)  stabilizes; halting 
E)  reduces; halting

Question 9

Which statement about the human respiratory system is true?

Accepted Answer

A)  Gas exchange occurs in the alveoli and in the small airways leading to them. 
B)  The thoracic cavity contains the lungs and is bounded by the ribs and the diaphragm. 
C)  The walls of bronchioles contain skeletal muscle. 
D)  Airways that conduct air to alveoli always contain fresh air. 
E)  Pleural membranes cover the lungs but do not line the thoracic cavity.

Question 10

Which statement about positive cooperativity of hemoglobin is true?

Accepted Answer

A)  Binding by the first O2 molecule means that a larger increase in PO2 is needed for hemoglobin to bind a second O2 molecule. 
B)  Positive cooperativity results from changes in the primary structure of hemoglobin. 
C)  Positive cooperativity applies for binding the fourth O2 molecule once a third O2 molecule is bound. 
D)  The linear relationship between PO2 and the amount of O2 bound to hemoglobin reflects positive cooperativity. 
E)  Binding by the second O2 molecule allows the third O2 molecule to bind more easily.

Question 11

Sensors for detecting PO₂ levels are found on two major arteries: the _______ and the carotid arteries.

Accepted Answer

The answer of Sensors for detecting PO₂ levels are found...

Question 12

Chemosensitive cells in the carotid bodies and aortic bodies are sensitive to the _______.When this falls, signals are sent to the medulla and cause a(n) _______ ventilation rate.This represents a _______ feedback control of breathing.

Accepted Answer

A)  PCO2 in your blood; decreased; negative 
B)  PO2 in your blood; increased; negative 
C)  PCO2 in the atmosphere; increased; positive 
D)  PO2 in the atmosphere; increased; positive 
E)  H+ level in your blood; decreased; negative

Question 13

Respiratory gases are exchanged between the body fluids of an animal and its environment by

Accepted Answer

A)  osmosis. 
B)  active transport. 
C)  diffusion. 
D)  passive transport. 
E)  pinocytosis.

Question 14

In humans, the process of exhalation is brought about in large part by

Accepted Answer

A)  the contraction of external intercostal muscles. 
B)  elastic recoil of the lung tissues. 
C)  contraction of the diaphragm. 
D)  complete collapse of the lung tissue. 
E)  lowering of pressure in the thoracic cavity.

Question 15

The notation PO₂ stands for the _______ of oxygen.

Accepted Answer

The answer of The notation PO₂ stands for the _______...

Question 16

The presence of CO2 in blood will lower blood pH because CO2 combines with _______ to form _______.The rate of the reaction is increased by _______.

Accepted Answer

A)  H2O; H+ and HCO3-; carbonic anhydrase 
B)  H2O; only HCO3-; carbonic anhydrase 
C)  H2O; only H+; carbonic ions 
D)  H+; HCO3-; oxyhemoglobin 
E)  H2O; H+ and HCO3-; fetal hemoglobin

Question 17

The lungs of _______ are the most efficient lungs of vertebrates.

Accepted Answer

The answer of The lungs of _______ are the most...

Question 18

Which feature characterizes carotid and aortic bodies?

Accepted Answer

A)  Chemosensors are associated with them on the ventral side of the medulla. 
B)  They are stimulated by increases in PO2. 
C)  They stimulate increased breathing rate when blood volume is high. 
D)  They prompt a reduction in breathing rate when blood pressure is very low. 
E)  They stimulate increased breathing rate at high altitude.

Question 19

In humans, the lower (posterior) side of the thoracic cavity is defined by the

Accepted Answer

A)  diaphragm. 
B)  esophagus. 
C)  stomach. 
D)  ribs. 
E)  intercostal muscles.

Question 20

Oxygen can be exchanged more easily in air than in water in part because

Accepted Answer

A)  the oxygen content of air is lower than that of water. 
B)  oxygen diffuses more slowly in water than in air. 
C)  water is less dense than air, so more energy is required to move it. 
D)  as water warms, the concentration of oxygen in the water increases. 
E)  as water warms, the partial pressure of oxygen in the water increases.

Exam 48: Gas Exchange

Refer to the graph. When you are exercising hard, you are producing more CO₂ in your muscles than you are when resting.This causes a shift in the oxygen-binding/dissociation curve of your hemoglobin, with the new curve looking like the curve labeled _______ in the graph.

Air is about 78% nitrogen, and atmospheric pressure is about 760 mm Hg at sea level.The partial pressure of nitrogen at sea level is about _______ mm Hg.

_______ is a condition in which respiratory problems result from inflammation that destroys the alveoli and leads to large, but few, alveoli.It is caused primarily by smoking and is a leading cause of death in the United States.

Which statement about gill ventilation in fishes is false?

One reason rapid gas exchange can be accomplished more easily in air than in water is that

If you climb a mountain to an altitude where the PO₂ is half of what it is at sea level, it is likely that

By converting CO₂ to H₂CO₃, carbonic anhydrase _the PCO₂ in endothelial cells, red blood cells, and plasma, thereby _ diffusion of CO₂ from tissue cells to these locations.

Which statement about the human respiratory system is true?

Which statement about positive cooperativity of hemoglobin is true?

Sensors for detecting PO₂ levels are found on two major arteries: the _______ and the carotid arteries.

Chemosensitive cells in the carotid bodies and aortic bodies are sensitive to the ___.When this falls, signals are sent to the medulla and cause a(n) _ ventilation rate.This represents a _____ feedback control of breathing.

Respiratory gases are exchanged between the body fluids of an animal and its environment by

In humans, the process of exhalation is brought about in large part by

The notation PO₂ stands for the _______ of oxygen.

The presence of CO₂ in blood will lower blood pH because CO₂ combines with ___ to form _.The rate of the reaction is increased by _____.

The lungs of _______ are the most efficient lungs of vertebrates.

Which feature characterizes carotid and aortic bodies?

In humans, the lower (posterior) side of the thoracic cavity is defined by the

Oxygen can be exchanged more easily in air than in water in part because

Exam 48: Gas Exchange

Refer to the graph. When you are exercising hard, you are producing more CO2 in your muscles than you are when resting.This causes a shift in the oxygen-binding/dissociation curve of your hemoglobin, with the new curve looking like the curve labeled _______ in the graph.

Air is about 78% nitrogen, and atmospheric pressure is about 760 mm Hg at sea level.The partial pressure of nitrogen at sea level is about _______ mm Hg.

_______ is a condition in which respiratory problems result from inflammation that destroys the alveoli and leads to large, but few, alveoli.It is caused primarily by smoking and is a leading cause of death in the United States.

Which statement about gill ventilation in fishes is false?

One reason rapid gas exchange can be accomplished more easily in air than in water is that

If you climb a mountain to an altitude where the PO2 is half of what it is at sea level, it is likely that

By converting CO2 to H2CO3, carbonic anhydrase _______the PCO2 in endothelial cells, red blood cells, and plasma, thereby _______ diffusion of CO2 from tissue cells to these locations.

Which statement about the human respiratory system is true?

Which statement about positive cooperativity of hemoglobin is true?

Sensors for detecting PO2 levels are found on two major arteries: the _______ and the carotid arteries.

Chemosensitive cells in the carotid bodies and aortic bodies are sensitive to the _______.When this falls, signals are sent to the medulla and cause a(n) _______ ventilation rate.This represents a _______ feedback control of breathing.

Respiratory gases are exchanged between the body fluids of an animal and its environment by

In humans, the process of exhalation is brought about in large part by

The notation PO2 stands for the _______ of oxygen.

The presence of CO2 in blood will lower blood pH because CO2 combines with _______ to form _______.The rate of the reaction is increased by _______.

The lungs of _______ are the most efficient lungs of vertebrates.

Which feature characterizes carotid and aortic bodies?

In humans, the lower (posterior) side of the thoracic cavity is defined by the

Oxygen can be exchanged more easily in air than in water in part because

Refer to the graph. When you are exercising hard, you are producing more CO₂ in your muscles than you are when resting.This causes a shift in the oxygen-binding/dissociation curve of your hemoglobin, with the new curve looking like the curve labeled _______ in the graph.

If you climb a mountain to an altitude where the PO₂ is half of what it is at sea level, it is likely that

By converting CO₂ to H₂CO₃, carbonic anhydrase _the PCO₂ in endothelial cells, red blood cells, and plasma, thereby _ diffusion of CO₂ from tissue cells to these locations.

Sensors for detecting PO₂ levels are found on two major arteries: the _______ and the carotid arteries.

Chemosensitive cells in the carotid bodies and aortic bodies are sensitive to the ___.When this falls, signals are sent to the medulla and cause a(n) _ ventilation rate.This represents a _____ feedback control of breathing.

The notation PO₂ stands for the _______ of oxygen.

The presence of CO₂ in blood will lower blood pH because CO₂ combines with ___ to form _.The rate of the reaction is increased by _____.