Test Bank For Vander's Human Physiology 15th Edition By Eric
Widmaier; Hershel Raff; Kevin Strang 9781259903885 Chapter
1-19 Complete Guide .
The conducting zone of the airways consists of - ANSWER: the trachea, bronchi, and terminal
bronchioles.
The respiratory zone of the airways consists of` - ANSWER: the alveoli, which are the sites of gas
exchange, and those airways to which alveoli are attached.
The alveoli are lined by - ANSWER: type I cells and some type II cells, which produce surfactant.
The lungs and interior of the thorax - ANSWER: are covered by pleura;
between the two pleural layers is an extremely thin layer of intrapleural fluid.
The lungs are elastic structures whose volume depends upon - ANSWER: the pressure difference
across the lungs—the transpulmonary
pressure—and how stretchable the lungs are.
In the steady state, the net volumes of oxygen and carbon dioxide exchanged in the lungs per unit
time - ANSWER: are equal to the net volumes exchanged in the tissues.
Airway resistance determines - ANSWER: how much air flows into the
lungs at any given pressure difference between atmosphere and alveoli.
The major determinants of airway resistance - ANSWER: the radii of the airways.
The vital capacity - ANSWER: the sum of resting tidal volume, inspiratory reserve volume, and
expiratory reserve volume.
The volume expired during the first second of a forced vital capacity measurement - ANSWER: the
FEV1 and normally averages 80% of forced vital capacity.
Minute ventilation - ANSWER: the product of tidal volume
and respiratory rate
Bulk flow of air between the atmosphere and alveoli - ANSWER: proportional to the difference
between the alveolar and
atmospheric pressures and inversely proportional to the airway resistance:F 5 (Palv 2 Patm)/R
Between breaths at the end of an unforced expiration - ANSWER: Patm 5 Palv, no air is flowing, and
the dimensions of the lungs and thoracic cage are stable as the result of opposing elastic forces
The lungs are stretched and are attempting to recoil,
whereas the chest wall is - ANSWER: compressed and attempting to move outward. This creates a
subatmospheric intrapleural pressure
and hence a transpulmonary pressure that opposes the forces of elastic recoil.
During inspiration, the contractions of the diaphragm and inspiratory intercostal muscles increase the
volume of the thoracic cage - ANSWER: This makes intrapleural pressure more subatmospheric,
increases transpulmonary pressure, and causes the lungs to expand to a greater degree than they do
between
breaths.
This expansion initially makes alveolar pressure
, subatmospheric, which creates the pressure difference between the atmosphere and alveoli to drive
airflow into the lungs.
During expiration, the inspiratory muscles cease contracting, allowing the elastic recoil of the lungs to
return them to their original between-breaths size - ANSWER: a. This initially compresses the alveolar
air, raising alveolar
pressure above atmospheric pressure and driving air out of
the lungs.
b. In forced expirations, the contraction of expiratory
intercostal muscles and abdominal muscles actively
decreases chest dimensions.
Lung compliance is determined by - ANSWER: the elastic connective
tissues of the lungs and the surface tension of the fluid lining the alveoli
The latter is greatly reduced—and compliance
increased—by surfactant, - ANSWER: produced by the type II cells of the alveoli. Surfactant also
stabilizes alveoli by decreasing surface
tension in smaller alveoli.
Exchange of gases in lungs and tissues is by diffusion as a result of - ANSWER: differences in partial
pressures. Gases diffuse from a region of higher partial pressure to one of lower partial pressure
At rest and at a respiratory quotient (RQ) of 0.8 - ANSWER: oxygen consumption is approximately 250
mL per minute, whereas
carbon dioxide production is approximately 200 mL per minute.
Normal alveolar gas pressure for oxygen is 105 mmHg and
for carbon dioxide is 40 mmHg. - ANSWER: a. At any given inspiredPO2, the ratio of oxygen
consumption
to alveolar ventilation determines alveolarPO
2—the higher
the ratio, the lower the alveolarPO2 .
b. The higher the ratio of carbon dioxide production to
alveolar ventilation, the higher the alveolarPCO2 .
The average value at rest for systemic venousPO2 - ANSWER: The average value at rest for systemic
venousPO2 is 40 mmHg and forPCO
2 is 46 mmHg.q
As systemic venous blood flows through the pulmonary
capillaries, there is net diffusion of oxygen from - ANSWER: alveoli to blood and of carbon dioxide
from blood to alveoli.
By the end of each pulmonary capillary, - ANSWER: the blood gas pressures have
become equal to those in the alveoli.
Inadequate gas exchange between alveoli and pulmonary capillaries may occur - ANSWER: when the
alveolar-capillary surface area is decreased, when the alveolar walls thicken, or when there
are ventilation-perfusion inequalities.
Significant ventilation-perfusion inequalities cause - ANSWER: the systemic arterial PO2 to be
reduced. An important mechanism for opposing
mismatching is that a low localPO2 causes local vasoconstriction,
diverting blood away from poorly ventilated areas.
Widmaier; Hershel Raff; Kevin Strang 9781259903885 Chapter
1-19 Complete Guide .
The conducting zone of the airways consists of - ANSWER: the trachea, bronchi, and terminal
bronchioles.
The respiratory zone of the airways consists of` - ANSWER: the alveoli, which are the sites of gas
exchange, and those airways to which alveoli are attached.
The alveoli are lined by - ANSWER: type I cells and some type II cells, which produce surfactant.
The lungs and interior of the thorax - ANSWER: are covered by pleura;
between the two pleural layers is an extremely thin layer of intrapleural fluid.
The lungs are elastic structures whose volume depends upon - ANSWER: the pressure difference
across the lungs—the transpulmonary
pressure—and how stretchable the lungs are.
In the steady state, the net volumes of oxygen and carbon dioxide exchanged in the lungs per unit
time - ANSWER: are equal to the net volumes exchanged in the tissues.
Airway resistance determines - ANSWER: how much air flows into the
lungs at any given pressure difference between atmosphere and alveoli.
The major determinants of airway resistance - ANSWER: the radii of the airways.
The vital capacity - ANSWER: the sum of resting tidal volume, inspiratory reserve volume, and
expiratory reserve volume.
The volume expired during the first second of a forced vital capacity measurement - ANSWER: the
FEV1 and normally averages 80% of forced vital capacity.
Minute ventilation - ANSWER: the product of tidal volume
and respiratory rate
Bulk flow of air between the atmosphere and alveoli - ANSWER: proportional to the difference
between the alveolar and
atmospheric pressures and inversely proportional to the airway resistance:F 5 (Palv 2 Patm)/R
Between breaths at the end of an unforced expiration - ANSWER: Patm 5 Palv, no air is flowing, and
the dimensions of the lungs and thoracic cage are stable as the result of opposing elastic forces
The lungs are stretched and are attempting to recoil,
whereas the chest wall is - ANSWER: compressed and attempting to move outward. This creates a
subatmospheric intrapleural pressure
and hence a transpulmonary pressure that opposes the forces of elastic recoil.
During inspiration, the contractions of the diaphragm and inspiratory intercostal muscles increase the
volume of the thoracic cage - ANSWER: This makes intrapleural pressure more subatmospheric,
increases transpulmonary pressure, and causes the lungs to expand to a greater degree than they do
between
breaths.
This expansion initially makes alveolar pressure
, subatmospheric, which creates the pressure difference between the atmosphere and alveoli to drive
airflow into the lungs.
During expiration, the inspiratory muscles cease contracting, allowing the elastic recoil of the lungs to
return them to their original between-breaths size - ANSWER: a. This initially compresses the alveolar
air, raising alveolar
pressure above atmospheric pressure and driving air out of
the lungs.
b. In forced expirations, the contraction of expiratory
intercostal muscles and abdominal muscles actively
decreases chest dimensions.
Lung compliance is determined by - ANSWER: the elastic connective
tissues of the lungs and the surface tension of the fluid lining the alveoli
The latter is greatly reduced—and compliance
increased—by surfactant, - ANSWER: produced by the type II cells of the alveoli. Surfactant also
stabilizes alveoli by decreasing surface
tension in smaller alveoli.
Exchange of gases in lungs and tissues is by diffusion as a result of - ANSWER: differences in partial
pressures. Gases diffuse from a region of higher partial pressure to one of lower partial pressure
At rest and at a respiratory quotient (RQ) of 0.8 - ANSWER: oxygen consumption is approximately 250
mL per minute, whereas
carbon dioxide production is approximately 200 mL per minute.
Normal alveolar gas pressure for oxygen is 105 mmHg and
for carbon dioxide is 40 mmHg. - ANSWER: a. At any given inspiredPO2, the ratio of oxygen
consumption
to alveolar ventilation determines alveolarPO
2—the higher
the ratio, the lower the alveolarPO2 .
b. The higher the ratio of carbon dioxide production to
alveolar ventilation, the higher the alveolarPCO2 .
The average value at rest for systemic venousPO2 - ANSWER: The average value at rest for systemic
venousPO2 is 40 mmHg and forPCO
2 is 46 mmHg.q
As systemic venous blood flows through the pulmonary
capillaries, there is net diffusion of oxygen from - ANSWER: alveoli to blood and of carbon dioxide
from blood to alveoli.
By the end of each pulmonary capillary, - ANSWER: the blood gas pressures have
become equal to those in the alveoli.
Inadequate gas exchange between alveoli and pulmonary capillaries may occur - ANSWER: when the
alveolar-capillary surface area is decreased, when the alveolar walls thicken, or when there
are ventilation-perfusion inequalities.
Significant ventilation-perfusion inequalities cause - ANSWER: the systemic arterial PO2 to be
reduced. An important mechanism for opposing
mismatching is that a low localPO2 causes local vasoconstriction,
diverting blood away from poorly ventilated areas.
