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?
1. 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
