Kin 335 Test 2 || A+ Guaranteed.
What is the principal function of the lung? correct answers Removal of CO2 is critical for pH &
acid-base regulation in body
Gas exchange (respiration)- O2 from air to venous blood & CO2 from venous blood to air
By what process do O2 and CO2 move between the air and blood within the lung? correct
answers Respiration in the mitochondria
Explain how the primary design features of the lung facilitate high rates of gas exchange correct
answers Lung is designed to maximize A and minimize T. This is achieved by ≈300 million
alveoli that are ≈0.3 micron thick
Pulmonary bp is so low that capillary endothelium wall and alveolar epithelium combined are
only 0.1-1 micron thick (0.3 microns in humans)
*High surface area
*Thin walls
*Low pulmonary blood pressure
Fick's law correct answers V gas = A/T x D(PA-Pblood)
What are the two zones of the lung and in which one does most of the gas reside? correct
answers 1- Conducting zone or dead space: airways do not exchange gases
2- Respiratory & transition zones: O2 and CO2 gas exchange area
How many airway bifurcations are found in the human lung? correct answers First 16 are in the
conducting zone or dead space. The last 7 make up the respiratory zone. 23 total.
Draw a graph depicting the relationship between airway generation and the total airway cross
sectional area. correct answers Total cross section area increases
exponentially in the respiratory zone. This
allows the forward velocity of gas to drop
to very low levels.
Gas movement at alveoli = diffusion and
not by bulk flow
What are the three cell types found in the alveoli and what are their functions correct answers
type I, type II, alveolar macrophages
type I correct answers make up 90% of alveolar wall
type II correct answers produces surfactant (lowers surface tension & high compliance)
alveolar macrophages correct answers cleaners, tiny particles too small to be filtered upstream
, What are the two main forms of connective tissue found in the lungs? correct answers Elastin
and collagen- make distensible elastic weave
ventilation at rest correct answers 7,500 ml/min
tidal volume (VT) correct answers 500 ml/min
respiratory frequency correct answers 15 bpm
alveolar gas volume (VA) correct answers 3,000 ml
dead space volume correct answers 150 ml
pulmonary capillary blood volume correct answers 70 ml
pulmonary blood flow correct answers 5,000 ml/min
functional residual capacity correct answers amount of air remaining in the lung after a normal
expiration
-no muscular forces acting on the lung
-amount of air available for gas exchange between breaths
residual volume correct answers volume of air in lungs after max expiration
-prevents lungs from collapsing
total lung capacity correct answers volume at maximal inhalation
-maximum amount lungs can hold
vital capacity correct answers maximum amount of air that can be exchanged in a single breath
tidal volume correct answers amount of air that inspiration bring in at rest
Explain why it is more difficult to breathe more deeply (increase tidal volume) than increase
breathing frequency correct answers You waste air that fills the dead space (conducting zone) ≈
150 mL when breathing in.
Rapid shallow breathing does not effectively increase useful alveolar ventilation and wastes too
much air in the dead space.
Where in the lung does most of the inspired air go and why correct answers Base of the lung-
alveoli are smaller at base, alveoli at apex have higher volume and don't expand easily. The base
gets more airflow and blood flow (due to gravity).
inspiration (muscles) correct answers diaphragm intercostal muscles, sternomastoids, scalene,
abductor muscles
What is the principal function of the lung? correct answers Removal of CO2 is critical for pH &
acid-base regulation in body
Gas exchange (respiration)- O2 from air to venous blood & CO2 from venous blood to air
By what process do O2 and CO2 move between the air and blood within the lung? correct
answers Respiration in the mitochondria
Explain how the primary design features of the lung facilitate high rates of gas exchange correct
answers Lung is designed to maximize A and minimize T. This is achieved by ≈300 million
alveoli that are ≈0.3 micron thick
Pulmonary bp is so low that capillary endothelium wall and alveolar epithelium combined are
only 0.1-1 micron thick (0.3 microns in humans)
*High surface area
*Thin walls
*Low pulmonary blood pressure
Fick's law correct answers V gas = A/T x D(PA-Pblood)
What are the two zones of the lung and in which one does most of the gas reside? correct
answers 1- Conducting zone or dead space: airways do not exchange gases
2- Respiratory & transition zones: O2 and CO2 gas exchange area
How many airway bifurcations are found in the human lung? correct answers First 16 are in the
conducting zone or dead space. The last 7 make up the respiratory zone. 23 total.
Draw a graph depicting the relationship between airway generation and the total airway cross
sectional area. correct answers Total cross section area increases
exponentially in the respiratory zone. This
allows the forward velocity of gas to drop
to very low levels.
Gas movement at alveoli = diffusion and
not by bulk flow
What are the three cell types found in the alveoli and what are their functions correct answers
type I, type II, alveolar macrophages
type I correct answers make up 90% of alveolar wall
type II correct answers produces surfactant (lowers surface tension & high compliance)
alveolar macrophages correct answers cleaners, tiny particles too small to be filtered upstream
, What are the two main forms of connective tissue found in the lungs? correct answers Elastin
and collagen- make distensible elastic weave
ventilation at rest correct answers 7,500 ml/min
tidal volume (VT) correct answers 500 ml/min
respiratory frequency correct answers 15 bpm
alveolar gas volume (VA) correct answers 3,000 ml
dead space volume correct answers 150 ml
pulmonary capillary blood volume correct answers 70 ml
pulmonary blood flow correct answers 5,000 ml/min
functional residual capacity correct answers amount of air remaining in the lung after a normal
expiration
-no muscular forces acting on the lung
-amount of air available for gas exchange between breaths
residual volume correct answers volume of air in lungs after max expiration
-prevents lungs from collapsing
total lung capacity correct answers volume at maximal inhalation
-maximum amount lungs can hold
vital capacity correct answers maximum amount of air that can be exchanged in a single breath
tidal volume correct answers amount of air that inspiration bring in at rest
Explain why it is more difficult to breathe more deeply (increase tidal volume) than increase
breathing frequency correct answers You waste air that fills the dead space (conducting zone) ≈
150 mL when breathing in.
Rapid shallow breathing does not effectively increase useful alveolar ventilation and wastes too
much air in the dead space.
Where in the lung does most of the inspired air go and why correct answers Base of the lung-
alveoli are smaller at base, alveoli at apex have higher volume and don't expand easily. The base
gets more airflow and blood flow (due to gravity).
inspiration (muscles) correct answers diaphragm intercostal muscles, sternomastoids, scalene,
abductor muscles
