COPD and Asthma Flashcards
Bronchus cross section cartoon
How will the bronchus shown change in an acute asthma attack?
- Swelling
- Bronchoconstriction
Most of the long-term, chronic changes to the bronchi seen in asthma are due to ___ released during an allergic attack.
Most of the long-term, chronic changes to the bronchi seen in asthma are due to TNFa released during an allergic attack.
Salmeterol
Long-acting beta 2 agonist
Taken for chronic asthma
Not only to beta 2 agonists relieve bronchoconstriction due to their effects on smooth muscle, but they also ____.
Not only to beta 2 agonists relieve bronchoconstriction due to their effects on smooth muscle, but they also decrease mast cell degranulation by binding to beta 2 receptors on the mast cells themselves.
Most common side effect of fluticasone
Thrush
Think about it: It decreases local immune activity. So, whatever infects the airways will be more likely to do so. As it happens, that is often Candida albicans.
What is the fundamental physical reason why emphysema patients can reach a new tidal breath pattern at a higher EELV?
Because the recoil forces of lung tissue are greater at higher volumes
In a state of dynamic hyperinflation, ___ is higher, but ___ is also higher. This is because ___.
In a state of dynamic hyperinflation, elastic recoil is higher, but work of inspiration is also higher. This is because muscles start at a lower length (beneath Lmax) and the respiratory system as a whole is less compliant.
So dyspnea is also increased.
“hyperresponsiveness” of airways
exaggerated response of airway smooth muscle to a wide variety of stimuli.
Seen in asthma, likely due to underlying inflammation
Extrinsic vs intrinsic asthma
extrinsic = atopic asthma
intrinstic = nonatopic asthma
Types of changes associated with asthmatic airway remodeling
- epithelial damage (probably from proteases)
- airway fibrosis
- smooth muscle hyperplasia
- nerve exposure
- Abundant eosinophils and lymphocytes
Some hypothesized effects from nerve exposure in asthma
- Low threshold for reflexes (irritant receptors are twitchy, cause bronchoconstriction)
- Release of tachykinin mediators (susbstance P, neurokinin A)
Tachykinins
Released from neurons. Short peptides with common C-term domain. Can stimulate neuron depolarizaiton, potent vasodilators, cause smooth muscle contraction
Where do leukotrienes vs histamine come from within the mast cell?
Histamine is presynthesized and stored.
Leukotrienes are synthesized immediately before release.
This and the fact that leukotrienes have such short half lives makes them excellent substrates for transcellular metabolism-modifiable signaling, where as histamine pretty much does what it does.
LOX pathways starting with linoleic acid or arachadonic acid
Lipoxygenases from 10,000 ft
Leukotrienes are all downstream of ____
Leukotrienes are all downstream of 5-LOX
Resolvins are all downstream of ____
Resolvins are all downstream of 15-LOX
(and acetylated COX-2)
In many patients, the return of FEV1 to normal is followed by . . .
In many patients, the return of FEV1 to normal is followed by a secondary delayed fall in FEV1 occurring hours after antigen exposure
This “late phase response” is due to the influx of the inflammatory cells called by the mast cell.
immediate repsonse = effects of mast cell’s mediators on local cells
late response = the effects of the cells that the mast cell called upon
___ can frequently provoke bronchoconstriction in patients with hyperreactive airways. This has to do with ___
Exercise can frequently provoke bronchoconstriction in patients with hyperreactive airways. This has to do with the inhalation of relatively cool, dry air. If the exercising asthmatic pathient is inhaling warm, water-saturated air, this will not occur.
The greatest difficulty with expiration in asthma patients occurs when the patienst are asked to . . .
The greatest difficulty with expiration in asthma patients occurs when the patienst are asked to perform a forced expiration
With forced expiration, pleural pressure becomes much more positive, thereby promoting airway narrowing and closure as well as air trapping.
The most common pattern of arterial blood gases for acute asthma patients
a low Po2 accompanied by a low Pco2 (respiratory alkalosis)
Mechanism is V/Q mismatch