An increase in smooth muscle tone in the airways in the respiratory zone of the lung.
A decrease in the diameter of the conducting zone airways
A loss of alveolar sacs
A decrease in the resistance of the airways.
Increased diffusion of respiratory gases
Decreased in a premature infant with inadequate secretion of surfactant
Unaffected by lung volume
Greatest at either lung volumes close to residual volume (RV) or total lung capacity (TLC).
. decreased in emphysema because of the loss of lung tissue
. lowest at lung volumes around FRC (functional residual capacity).
. Patm = Ppl < PA < Pm
Patm > Ppl < PA = Pm
. Patm < Ppl > PA < Pm
Patm > Ppl = PA < Pm
Patm > Ppl < PA < Pm
Contain skeletal muscle.
Contain ciliated cells and mucus-secreting cells.
Include the respiratory bronchioles
Are lined with Type I cells that secrete surfactant.
Help to sense the atmospheric oxygen concentration
Refers to the amount of O2 produced during anaerobic metabolism.
With a diet of only carbohydrates would be 0.7
Increases as the diet becomes higher in fat.
Is calculated as the amount of CO2 produced divided by the amount of O2 consumed
Is constant and unchanging
An increase in the surface area of the lung
An increase in the concentration gradient for oxygen.
A decrease in the thickness of the membrane.
The presence of hemoglobin in the red blood cell.
The presence of carbon monoxide (CO)
Equal to atmospheric pressure whenever there is no flow
Subatmospheric at rest
Subatmospheric during expiration
Equal and opposite to the pleural pressure
4, 1, 5, 6, 3, 2
1, 2, 3, 4, 5, 6
4, 1, 2, 6, 3, 5
1, 2, 3, 5, 6, 4
The pleural pressure at the apex is about the same as the pressure at the base.
The accessory muscles are activated.
Their compliance is relatively high.
The resistance to inspiratory airflow is less in the apex.
External intercostal muscles
Increases the surface tension of the lung
Depends on secretion by the alveolar Type I cells
Encourages collapse of the small alveoli into larger ones
Increases the lung compliance
Occurs in the intrapleural space
Functional residual capacity
Expiratory reserve volume
Total lung capacity
Inspiratory reserve volume
. 4 Liters
Mixed venous blood is usually 75% saturated with oxygen
Increased hemoglobin concentrations increase the % Hb saturation
About 10 % of the oxygen is transported in a dissolved form
The arterial Po2 is usually greater than the alveolar Po2
The arterial Pco2 is usually 46 mm Hg
Them to be hyperventilating
Their arterial Pco2 to be lower than normal
Their hemoglobin-oxygen saturation curve to be shifted to the right
Them to have more carbonic anhydrase
A decreased anatomic dead space
External intercostal muscles
Accessory muscles and diaphragm
External and internal intercostal muscles
Abdominal and external intercostals muscles
Diaphragm and internal intercostal muscles
Increase , increase
Stay the same, increase
Decrease , stay the same
Increase , decrease
Decrease , increase
. in the head-down position
In the upright position.
When the pulmonary arterial pressure decreases.
When “Zone 1” is increased
Po2 = dead space Po2 > alveolar Po2 = arterial Po2 > venous Po2
Atmospheric Po2 = dead space Po2 > alveolar Po2 = arterial Po2 < venous Po2
Atmospheric Po2 > dead space Po2 > alveolar Po2 = arterial Po2 > venous Po2
Atmospheric Po2 > dead space Po2 > alveolar Po2 > arterial Po2 > venous Po2