Question 1

Match the physiological factors, labelled a. through e., with the descriptions. (Options may be used more than once or not at all.)
-stimulates peripheral chemoreceptors as an emergency mechanism
A)arterial PO₂ between 60 to 100 mmHg
B)arterial PO₂ less than 60 mmHg
C)arterial PCO₂ increased above normal
D)brain ECF H⁺ increased above normal
E)arterial H⁺ increased above normal

Accepted Answer

Peripheral chemoreceptors are stimulated as an emergency mechanism when arterial PO₂ falls below 60 mmHg, triggering an increase in ventilation to raise oxygen levels.

Question 2

Match the physiological factors, labelled a. through e., with the descriptions. (Options may be used more than once or not at all.)
-directly stimulates the central chemoreceptors
A)arterial PO₂ between 60 to 100 mmHg
B)arterial PO₂ less than 60 mmHg
C)arterial PCO₂ increased above normal
D)brain ECF H⁺ increased above normal
E)arterial H⁺ increased above normal

Accepted Answer

The answer of Match the physiological factors, labelled a. through...

Question 3

Match the physiological factors, labelled a. through e., with the descriptions. (Options may be used more than once or not at all.)
-weakly stimulates the peripheral chemoreceptors
A)arterial PO₂ between 60 to 100 mmHg
B)arterial PO₂ less than 60 mmHg
C)arterial PCO₂ increased above normal
D)brain ECF H⁺ increased above normal
E)arterial H⁺ increased above normal

Accepted Answer

The answer of Match the physiological factors, labelled a. through...

Question 4

Match the effects on the rate of gas transfer, labelled a. through c., with the changes listed. (Options may be used more than once or not at all.)
-the effect of emphysema on O₂ and CO₂ exchange within the lungs
A)This change would increase the rate of gas transfer.
B)This change would decrease the rate of gas transfer.
C)This change would have no effect on the rate of gas transfer.

Accepted Answer

Emphysema, which is characterized by destruction of the alveolar walls and loss of elastic recoil, leads to a decrease in the surface area available for gas exchange and a decrease in the efficiency of ventilation-perfusion matching. As a result, the rate of gas transfer is decreased.

Question 5

Match the physiological factors, labelled a. through e., with the descriptions. (Options may be used more than once or not at all.)
-blood-borne factor that has no effect on the peripheral chemoreceptors
A)arterial PO₂ between 60 to 100 mmHg
B)arterial PO₂ less than 60 mmHg
C)arterial PCO₂ increased above normal
D)brain ECF H⁺ increased above normal
E)arterial H⁺ increased above normal

Accepted Answer

The answer of Match the physiological factors, labelled a. through...

Question 6

Match the effects on the rate of gas transfer, labelled a. through c., with the changes listed. (Options may be used more than once or not at all.)
-the effect of reduced systemic venous PO₂ on O₂ exchange within the lungs
A)This change would increase the rate of gas transfer.
B)This change would decrease the rate of gas transfer.
C)This change would have no effect on the rate of gas transfer.

Accepted Answer

Reduced systemic venous PO₂ would lead to a decreased O₂ saturation in the blood returning to the lungs, resulting in an increased gradient for O₂ diffusion into the blood. Hence, the rate of gas transfer would increase.

Question 7

Match the effects on the rate of gas transfer, labelled a. through c., with the changes listed. (Options may be used more than once or not at all.)
-the effect on O₂ exchange in the lungs by replacing part of the nitrogen with helium so that the inspired air consists of 60 percent N, 19 percent He, and 21 percent O₂
A)This change would increase the rate of gas transfer.
B)This change would decrease the rate of gas transfer.
C)This change would have no effect on the rate of gas transfer.

Accepted Answer

The answer of Match the effects on the rate of...

Question 8

Match the effects on the rate of gas transfer, labelled a. through c., with the changes listed. (Options may be used more than once or not at all.)
-the effect of a fall in atmospheric PO₂ on O₂ exchange within the lungs
A)This change would increase the rate of gas transfer.
B)This change would decrease the rate of gas transfer.
C)This change would have no effect on the rate of gas transfer.

Accepted Answer

A decrease in atmospheric partial pressure of oxygen (PO₂) would reduce the gradient for oxygen diffusion from the air into the blood, thus decreasing the rate of gas transfer.

Question 9

Match the physiological factors, labelled a. through e., with the descriptions. (Options may be used more than once or not at all.)
-stimulates the peripheral chemoreceptors
A)arterial PO₂ between 60 to 100 mmHg
B)arterial PO₂ less than 60 mmHg
C)arterial PCO₂ increased above normal
D)brain ECF H⁺ increased above normal
E)arterial H⁺ increased above normal

Accepted Answer

The answer of Match the physiological factors, labelled a. through...

Question 10

Match the physiological factors, labelled a. through e., with the descriptions. (Options may be used more than once or not at all.)
-represents the dominant control of ventilation
A)arterial PO₂ between 60 to 100 mmHg
B)arterial PO₂ less than 60 mmHg
C)arterial PCO₂ increased above normal
D)brain ECF H⁺ increased above normal
E)arterial H⁺ increased above normal

Accepted Answer

The answer of Match the physiological factors, labelled a. through...

Question 11

Match the effects on the rate of gas transfer, labelled a. through c., with the changes listed. (Options may be used more than once or not at all.)
-the effect of increased metabolism of a cell on O₂ and CO₂ exchange between the cell and blood
A)This change would increase the rate of gas transfer.
B)This change would decrease the rate of gas transfer.
C)This change would have no effect on the rate of gas transfer.

Accepted Answer

Increased metabolism of a cell would lead to an increased demand for oxygen and production of carbon dioxide. This would increase the partial pressure gradient between the cell and the blood, driving more oxygen into the cell and more carbon dioxide out of the cell, resulting in an increased rate of gas transfer.

Question 12

Match the physiological factors, labelled a. through e., with the descriptions. (Options may be used more than once or not at all.)
-directly depresses the central chemoreceptors
A)arterial PO₂ between 60 to 100 mmHg
B)arterial PO₂ less than 60 mmHg
C)arterial PCO₂ increased above normal
D)brain ECF H⁺ increased above normal
E)arterial H⁺ increased above normal

Accepted Answer

The answer of Match the physiological factors, labelled a. through...

Question 13

Match the effects on the rate of gas transfer, labelled a. through c., with the changes listed. (Options may be used more than once or not at all.)
-the effect of tissue oedema on O₂ and CO₂ exchange between the surrounding cells and blood
A)This change would increase the rate of gas transfer.
B)This change would decrease the rate of gas transfer.
C)This change would have no effect on the rate of gas transfer.

Accepted Answer

Tissue oedema, which is excess fluid accumulation in the tissues, can decrease the rate of gas transfer between the surrounding cells and blood by creating a greater distance for diffusion to occur and reducing the surface area available for gas exchange. Therefore, the best choice for the effect of tissue oedema on gas transfer is B, which indicates a decrease in the rate of gas transfer.

Quiz 12: The Respiratory System

Match the physiological factors, labelled a. through e., with the descriptions. (Options may be used more than once or not at all.) -stimulates peripheral chemoreceptors as an emergency mechanism

Match the physiological factors, labelled a. through e., with the descriptions. (Options may be used more than once or not at all.) -directly stimulates the central chemoreceptors

Match the physiological factors, labelled a. through e., with the descriptions. (Options may be used more than once or not at all.) -weakly stimulates the peripheral chemoreceptors

Match the effects on the rate of gas transfer, labelled a. through c., with the changes listed. (Options may be used more than once or not at all.) -the effect of emphysema on O₂ and CO₂ exchange within the lungs

Match the physiological factors, labelled a. through e., with the descriptions. (Options may be used more than once or not at all.) -blood-borne factor that has no effect on the peripheral chemoreceptors

Match the effects on the rate of gas transfer, labelled a. through c., with the changes listed. (Options may be used more than once or not at all.) -the effect of reduced systemic venous PO₂ on O₂ exchange within the lungs

Match the effects on the rate of gas transfer, labelled a. through c., with the changes listed. (Options may be used more than once or not at all.) -the effect of a fall in atmospheric PO₂ on O₂ exchange within the lungs

Match the physiological factors, labelled a. through e., with the descriptions. (Options may be used more than once or not at all.) -stimulates the peripheral chemoreceptors

Match the physiological factors, labelled a. through e., with the descriptions. (Options may be used more than once or not at all.) -represents the dominant control of ventilation

Match the effects on the rate of gas transfer, labelled a. through c., with the changes listed. (Options may be used more than once or not at all.) -the effect of increased metabolism of a cell on O₂ and CO₂ exchange between the cell and blood

Match the physiological factors, labelled a. through e., with the descriptions. (Options may be used more than once or not at all.) -directly depresses the central chemoreceptors

Match the effects on the rate of gas transfer, labelled a. through c., with the changes listed. (Options may be used more than once or not at all.) -the effect of tissue oedema on O₂ and CO₂ exchange between the surrounding cells and blood