Surface Tension/Airway Resistance Flashcards
Stimulation of adrenergic receptors by endogenous ______ and ______ causes bronchodilation via activation of β2 receptors, as do drugs such as isoproterenol.
epinephrine; norepinephrine
An important factor in determining compliance is _____.
surface tension
Where does surfactant come from?
type II alveolar surface epi cells
The major site of airway resistance is found at the ______.
intermediate-sized bronchi
Stimulation of adrenergic receptors by endogenous epinephrine and norepinephrine causes bronchodilation via activation of β2 receptors, as do drugs such as ______.
isoproterenol
How do emphysemics combat airway collapse?
they expire while pursing their lips to maintain a larger air pressure in the airways (PAW) to keep the airway open
What are the problems created by surface tension in alveoli?
- Reduced lung compliance
- Fluid accumulation in alveoli
- Collapse of small alveoli
Surfactant’s efficacy increases in _____.
smaller alveoli
The surface tension of water is tamed by _____.
pulmonary surfactant
What are the factors that control airway resistance?
- lung volume
- bronchial smooth muscle tone
- dynamic airway collapse
Vagal stimulation induces ______ via release of acetylcholine.
bronchoconstriction
Stimulation of ______ by endogenous epinephrine and norepinephrine causes bronchodilation via activation of β2 receptors, as do drugs such as isoproterenol.
adrenergic receptors
What is pulmonary surfactant made of?
a mixture of lipids and proteins
Respiratory distress syndrome (in infants) is characterized by _____.
a surfactant deficiency
_______ is characterized by a surfactant deficiency.
Respiratory distress syndrome (in infants)
Why do emphysemics have airway collapse?
- reduced lung recoil 2. expiratory muscle use 3. loss of supporting CT in the airway
In addition to acetylcholine, ______ contracts in response to histamine, several products of arachidonic acid metabolism (e.g., thromboxane A2, leukotrienes C4 and D4), and a low carbon dioxide partial pressure PCO2 in the airways.
bronchial smooth muscle
Vagal stimulation induces bronchoconstriction via release of _______.
acetylcholine
Surface tension is a property of the water that lines the inner surfaces of _____.
alveoli
Bronchial smooth muscle is innervated by _____.
the vagus nerve
In addition to acetylcholine, bronchial smooth muscle contracts in response to?
- histamine
- several products of arachidonic acid metabolism (e.g., thromboxane A2, leukotrienes C4 and D4)
- a low carbon dioxide partial pressure (PCO2) in the airways
What does surfactant do?
- increase lung compliance
- prevent collapse of small alveoli
- prevent the accumulation of fluid inside the alveoli
For a 2-fold reduction in radius, R increases ______.
16-fold
Stimulation of adrenergic receptors by endogenous epinephrine and norepinephrine causes _______ via activation of ______, as do drugs such as isoproterenol.
bronchodilation; β2 receptors
