MEDSCI 142 - Respiratory Physiology Test with Answers Rated A
a - correct; tidal volume is the amount you breathe in and
Tidal volume is always: out when relaxed so is less than maximum but more than
a) greater than zero and less that total lung capacity zero
b) greater than residual volume b - no; we cant measure residual volume so dont know
c) greater than functional residual capacity c - no; FRC includes residual capacity, which cant be mea-
d) greater than residual capacity and less than total lung sured
capacity d - no; less than total lung capacity but dont know volume
e) all options are correct of residual capacity
e - no
The lung:
a) exchanges CO2 between alveolar air and pulmonary
capillary blood
b) exchanges H2O between alveolar air and ambient air e - all options are correct; the lung serves all of these
c) exchanges heat between alveolar air and ambient air functions
d) exchanges O2 between alveolar air and pulmonary
capillary blood
e) all options are correct
Excitation of the phrenic nerve will:
a) increase volume of thorax by causing elevation of di-
aphragm a - no; elevation of diaphragm will decrease volume
b) reduce volume of thorax by causing elevation of the b - no; excitation of the nerve will not cause elevation of
diaphragm diaphragm
c) increase volume of the thorax by causing relaxation of c - no; excitation will not relax the diaphragm
the diaphragm d - correct; excitation will contract the diaphragm, causing
d) increase volume of the thorax by causing contraction of it to go down and increase thorax volume
the diaphragm e - no; contraction causes expansion of the volume
e) reduce volume of the thorax by causing contraction of
the diaphragm
During inspiration:
a) the glottis is open and alveolar air pressure is above
, MEDSCI 142 - Respiratory Physiology Test with Answers Rated A
atmospheric
b) the glottis is open and alveolar air pressure is equal to
atm If alveolar air pressure was above atmospheric, it would
c) the glottis is open and alveolar air pressure is less that want to equalise and the air would leave the lungs, not go
atm in. Due to expansion of the alveoli, the pressure decreases.
d) the glottis is closed and alveolar air pressure is above The glottis is only closed for swallowing food, so
atm c - correct
e) the glottis is closed and alveolar air pressure is below
atm
In pneumonia, bacterial infection causes the alveoli to
become filled with liquid, thereby reducing the space for
air. This condition would be expected to:
a) decrease the surface area for dittusive exchange of O2 Reducing space for air means less surface area available
b) decrease the surface are for dittusive exchange of CO2 for gas exchange, but also means more thickness for the
c) increase the dittusion distance of O2 between air and exchange to have to work through
blood e - all options are correct
d) increase the dittusion distance of CO2 between air and
blood
e) all options are correct
Ventilation is increased by:
a) a decrease in partial pressure of CO2 in the cere-
Increase in ventilation is usually due to lower O2, and a
brospinal fluid
need to increase O2. A decrease in CO2 would not trigger
b) a decrease in partial pressure of CO2 in the blood
this.
supply to the carotid bodies
d - decrease in pH can occur due to increase in CO2 so
c) decrease in partial pressure of CO2 in the inspired air
ventilation is needed to correct pH
d) decrease of pH of the cerebrospinal fluid
e) all options are correct
Hyperventilation will lead to: a - correct, more oxygen will go into the blood
a) increase of arteriolar Po2 b - no, Po2 at alveoli will not change, just the total amount
b) decrease of alveolar Po2 c - no, same as above
c) increase of alveolar Pco2 d - no, breathing in more will not lead to more Pco2 in
, MEDSCI 142 - Respiratory Physiology Test with Answers Rated A
d) increase of arteriolar Pco2 arteries
e) all options are correct e - no
The human pulmonary system:
a) senses Po2 and Pco2 in the carotid and aortic bodies a - yes, peripheral chemoreceptors are located here
b) is responsive to the pH of the cerebrospinal fluid b - yes, H ions will trigger the central chemoreceptors
c) is more responsive to an excess of CO2 than to lack of c - yes, dog-leg relationship graph c.f. Po2 graph
O2 d - yes, mechanoreceptors
d) contain stretch receptors in lung tissue e - correct
e) all options are correct
Which of the following is not considered a function of the
a - correct; this is what the blood does. The respiratory
respiratory system?
system transports O2 and CO2 to the blood, not tissues
a) transport of O2 and CO2 to tissue cells
b - true
b) intake of O2 and elimination of CO2
c - true
c) filtering inspired air
d - CO2 can change blood pH
d) regulation of acid-base balance
e - yes, via the larynx
e) production of sound
During normal resting pulmonary ventilation, all of the
following are true, EXCEPT:
a) thoracic volume increases as diaphragm contracts dur- a - true, diaphragm lowers and makes more room
ing inspiration b - true
b) the diaphragm forms a dome as it relaxes c - true, as lungs expand, alveolar pressure drops and
c) air comes in during inspiration because alveolar pres- draws in air
sure falls below atm d - true
d) the phrenic nerve stimulates contraction of the di- e - correct; intrapleural pressure increases during inhala-
aphragm tion, but never above atmospheric
e) intrapleural pressure increases above atm during ex-
halation
The reason the gradients for carbon dioxide can be small-
er than those for oxygen and still meet the body's needs
is that:
a - correct; tidal volume is the amount you breathe in and
Tidal volume is always: out when relaxed so is less than maximum but more than
a) greater than zero and less that total lung capacity zero
b) greater than residual volume b - no; we cant measure residual volume so dont know
c) greater than functional residual capacity c - no; FRC includes residual capacity, which cant be mea-
d) greater than residual capacity and less than total lung sured
capacity d - no; less than total lung capacity but dont know volume
e) all options are correct of residual capacity
e - no
The lung:
a) exchanges CO2 between alveolar air and pulmonary
capillary blood
b) exchanges H2O between alveolar air and ambient air e - all options are correct; the lung serves all of these
c) exchanges heat between alveolar air and ambient air functions
d) exchanges O2 between alveolar air and pulmonary
capillary blood
e) all options are correct
Excitation of the phrenic nerve will:
a) increase volume of thorax by causing elevation of di-
aphragm a - no; elevation of diaphragm will decrease volume
b) reduce volume of thorax by causing elevation of the b - no; excitation of the nerve will not cause elevation of
diaphragm diaphragm
c) increase volume of the thorax by causing relaxation of c - no; excitation will not relax the diaphragm
the diaphragm d - correct; excitation will contract the diaphragm, causing
d) increase volume of the thorax by causing contraction of it to go down and increase thorax volume
the diaphragm e - no; contraction causes expansion of the volume
e) reduce volume of the thorax by causing contraction of
the diaphragm
During inspiration:
a) the glottis is open and alveolar air pressure is above
, MEDSCI 142 - Respiratory Physiology Test with Answers Rated A
atmospheric
b) the glottis is open and alveolar air pressure is equal to
atm If alveolar air pressure was above atmospheric, it would
c) the glottis is open and alveolar air pressure is less that want to equalise and the air would leave the lungs, not go
atm in. Due to expansion of the alveoli, the pressure decreases.
d) the glottis is closed and alveolar air pressure is above The glottis is only closed for swallowing food, so
atm c - correct
e) the glottis is closed and alveolar air pressure is below
atm
In pneumonia, bacterial infection causes the alveoli to
become filled with liquid, thereby reducing the space for
air. This condition would be expected to:
a) decrease the surface area for dittusive exchange of O2 Reducing space for air means less surface area available
b) decrease the surface are for dittusive exchange of CO2 for gas exchange, but also means more thickness for the
c) increase the dittusion distance of O2 between air and exchange to have to work through
blood e - all options are correct
d) increase the dittusion distance of CO2 between air and
blood
e) all options are correct
Ventilation is increased by:
a) a decrease in partial pressure of CO2 in the cere-
Increase in ventilation is usually due to lower O2, and a
brospinal fluid
need to increase O2. A decrease in CO2 would not trigger
b) a decrease in partial pressure of CO2 in the blood
this.
supply to the carotid bodies
d - decrease in pH can occur due to increase in CO2 so
c) decrease in partial pressure of CO2 in the inspired air
ventilation is needed to correct pH
d) decrease of pH of the cerebrospinal fluid
e) all options are correct
Hyperventilation will lead to: a - correct, more oxygen will go into the blood
a) increase of arteriolar Po2 b - no, Po2 at alveoli will not change, just the total amount
b) decrease of alveolar Po2 c - no, same as above
c) increase of alveolar Pco2 d - no, breathing in more will not lead to more Pco2 in
, MEDSCI 142 - Respiratory Physiology Test with Answers Rated A
d) increase of arteriolar Pco2 arteries
e) all options are correct e - no
The human pulmonary system:
a) senses Po2 and Pco2 in the carotid and aortic bodies a - yes, peripheral chemoreceptors are located here
b) is responsive to the pH of the cerebrospinal fluid b - yes, H ions will trigger the central chemoreceptors
c) is more responsive to an excess of CO2 than to lack of c - yes, dog-leg relationship graph c.f. Po2 graph
O2 d - yes, mechanoreceptors
d) contain stretch receptors in lung tissue e - correct
e) all options are correct
Which of the following is not considered a function of the
a - correct; this is what the blood does. The respiratory
respiratory system?
system transports O2 and CO2 to the blood, not tissues
a) transport of O2 and CO2 to tissue cells
b - true
b) intake of O2 and elimination of CO2
c - true
c) filtering inspired air
d - CO2 can change blood pH
d) regulation of acid-base balance
e - yes, via the larynx
e) production of sound
During normal resting pulmonary ventilation, all of the
following are true, EXCEPT:
a) thoracic volume increases as diaphragm contracts dur- a - true, diaphragm lowers and makes more room
ing inspiration b - true
b) the diaphragm forms a dome as it relaxes c - true, as lungs expand, alveolar pressure drops and
c) air comes in during inspiration because alveolar pres- draws in air
sure falls below atm d - true
d) the phrenic nerve stimulates contraction of the di- e - correct; intrapleural pressure increases during inhala-
aphragm tion, but never above atmospheric
e) intrapleural pressure increases above atm during ex-
halation
The reason the gradients for carbon dioxide can be small-
er than those for oxygen and still meet the body's needs
is that:
