EXAM3/CH20- Asthma Flashcards
what type of disorder is asthma
chronic inflammatory disorder
what occurs in asthma
airway hyperresponsiveness causes recurrent episodes of airflow obstruction
-if you have asthma, your airways will respond more to things like smoke, pollen, etc.
quicker + more pronounced response
asthma symptoms
-wheezing
-breathlessness
-chest tightness
-coughing
when do asthma episodes typically occur
particularly at night or in the early morning
-reversible either spontaneously or with treatment
wheezing
high pitched sound during inspiration + expiration
what is typically the first + last symptom to occur/resolve in an asthma attack
cough
spontaneous reversal
if you remove the stimulus (smoke, pollen, etc.)
disease scope of asthma
-a worldwide problem with an estimated 300 million affected
-22 million Americans affected
-5% increase per year in the world
-higher in some populations (23% of inner-city African Americans vs. 5% of Caucasians)
when does most childhood asthma begin
infancy (less than 3 years of age)
asthma pathophysiology
-host factors (innate immunity, genetics) predispose to airway hyperresponsiveness
-stimuli are environmental (airborne allergens, viral respiratory infections, cold air)
-CD4 lymphocytes promote inflammation by activating eosinophils + mast cells
-cellular interactions are regulated by a cascade of inflammatory mediators
____ promote inflammation by activating ____ + ____
CD4 lymphocytes
eosinophils
mast cells
-all involved in the inflammatory cascade that results in bronchoconstriction
asthma- acute process (minutes to hours)
-airway inflammation stimulates bronchoconstriction, mucus secretion, + edematous swelling
-these obstruct airflow causing asthma ‘attacks’ which are episodic + (usually) reversible
bronchoconstriction
tightening of the airways
edematous swelling
the tissue itself accumulates fluid + begins to swell
asthma- chronic process (months to years)
-airway epithelium is damaged
-fibrosis due to collagen deposition
-smooth muscle hypertrophy, hyperplasia
-angiogenesis
what does collagen deposition do to the lungs
causes lung tissue to become stiffer
hyperplasia
increase in cell number
angiogenesis
growth of blood vessels
what cells line the airways
columnar epithelial cells
epithelial cells have ____
cilia
cilia
little hairs that are active + beat to move mucus up + out of lungs to clear foreign material from airways
-the mucus that exists in the lungs is made by the lungs by mucus glands (see dark epithelial invagination to the left of image)
-mucus is sticky so it captures dust + other foreign matter
-the cilia will then beat the mucus out of the lungs so you can swallow it or spit it out
-“mucociliary escalator”- rids lungs of foreign matter