Mike is sitting in his
athletic training suite feeling sorry for himself. He movedfrom
Southern California to play soccer at Northern MinnesotaUniversity
(NMU) as a highly recruited player. All was well until he gotsick
with a miserable cold. He soon recovered, but now he findshimself
with a lingering dry cough and difficulty catching his breathany
time he exerts himself, which is every day! He also notices ithas
gotten worse as the weather has become colder. To makethings
worse, Mike feels, and looks, like he's out of shape, so hiscoach
has been criticizing him for dogging it. A few days later,Mike
relays his story to JP, the head athletic trainer at NMU."I'm
thinking my cold is coming back, or something else is wrongwith
me. When I'm just hanging out, like now, I feel fine. But assoon
as I start to run I get winded and can't stop coughing." JPlistens
to Mike's breathing sounds with his stethoscope, but hearsnothing
abnormal. So he tells Mike to come back as soon as thesymptoms
return during soccer practice. Twenty minutes later, Mike isback
in the athletic training suite, audibly wheezing, coughing,and
short of breath. The team physician, Dr. McInnis, happens tobe
there and performs a complete physical exam. He also doespulmonary
function tests with Mike using spirometry, including a forcedvital
capacity (FVC) and forced expiratory volume in one second(FEV1).
He instructs Mike to take a maximal inhalation and then exhaleas
forcefully and maximally as possible into the spirometer. Basedon
his findings, Dr. McInnis tells Mike he thinks he isexperiencing
cold-induced bronchoconstriction (also called cold-inducedasthma),
which is made worse by exertion. The doctor explains to Mikethat
his recent upper respiratory infection probably inflamed his
airways, making them hypersensitive and reactive to irritants,such
as cold and physical exertion. When Mike exercises in thecold,
autumn afternoons of Minnesota, his sensitive airwaystemporarily
bronchoconstrict, causing the symptoms he is experiencing.Asthma
is almost always a reversible condition. Dr. McInnis prescribestwo
puffs of an albuterol inhaler, to be used 10 minutes before about
of exercise in the cold.
How does Mike's body make the necessary
changes in intrapulmonary pressure to maintain normal air flowwhen
he is experiencing cold-induced asthma?
What must happen to Mike's intrapulmonary pressure in order forhim to maintain normal air flow during inhalation and exhalationwhen he is having one of his asthma attacks?
Albuterol is a selective beta-2 adrenergic agonist, which meansit specifically activates beta-2 adrenergic receptors on smoothmuscle in the airways. How does this improve Mike's asthma?
Several physical factors that influence the efficiency ofpulmonary ventilation are compliance, alveolar surface tension, andairway resistance. Briefly describe each factor and identify theone that is affecting Mike's efficiency of breathing.
Describe the relationship between intrapulmonary pressure,atmospheric pressure, and air flow during normal inspiration andexpiration, referring to Boyle's law.
Resistance varies in Mike's conducting airways. Using yourunderstanding of respiratory anatomy, explain where in his airwaythe resistance is highest and why.
Mike is sitting in his
athletic training suite feeling sorry for himself. He movedfrom
Southern California to play soccer at Northern MinnesotaUniversity
(NMU) as a highly recruited player. All was well until he gotsick
with a miserable cold. He soon recovered, but now he findshimself
with a lingering dry cough and difficulty catching his breathany
time he exerts himself, which is every day! He also notices ithas
gotten worse as the weather has become colder. To makethings
worse, Mike feels, and looks, like he's out of shape, so hiscoach
has been criticizing him for dogging it. A few days later,Mike
relays his story to JP, the head athletic trainer at NMU."I'm
thinking my cold is coming back, or something else is wrongwith
me. When I'm just hanging out, like now, I feel fine. But assoon
as I start to run I get winded and can't stop coughing." JPlistens
to Mike's breathing sounds with his stethoscope, but hearsnothing
abnormal. So he tells Mike to come back as soon as thesymptoms
return during soccer practice. Twenty minutes later, Mike isback
in the athletic training suite, audibly wheezing, coughing,and
short of breath. The team physician, Dr. McInnis, happens tobe
there and performs a complete physical exam. He also doespulmonary
function tests with Mike using spirometry, including a forcedvital
capacity (FVC) and forced expiratory volume in one second(FEV1).
He instructs Mike to take a maximal inhalation and then exhaleas
forcefully and maximally as possible into the spirometer. Basedon
his findings, Dr. McInnis tells Mike he thinks he isexperiencing
cold-induced bronchoconstriction (also called cold-inducedasthma),
which is made worse by exertion. The doctor explains to Mikethat
his recent upper respiratory infection probably inflamed his
airways, making them hypersensitive and reactive to irritants,such
as cold and physical exertion. When Mike exercises in thecold,
autumn afternoons of Minnesota, his sensitive airwaystemporarily
bronchoconstrict, causing the symptoms he is experiencing.Asthma
is almost always a reversible condition. Dr. McInnis prescribestwo
puffs of an albuterol inhaler, to be used 10 minutes before about
of exercise in the cold.
How does Mike's body make the necessary
changes in intrapulmonary pressure to maintain normal air flowwhen
he is experiencing cold-induced asthma?
What must happen to Mike's intrapulmonary pressure in order forhim to maintain normal air flow during inhalation and exhalationwhen he is having one of his asthma attacks?
Albuterol is a selective beta-2 adrenergic agonist, which meansit specifically activates beta-2 adrenergic receptors on smoothmuscle in the airways. How does this improve Mike's asthma?
Several physical factors that influence the efficiency ofpulmonary ventilation are compliance, alveolar surface tension, andairway resistance. Briefly describe each factor and identify theone that is affecting Mike's efficiency of breathing.
Describe the relationship between intrapulmonary pressure,atmospheric pressure, and air flow during normal inspiration andexpiration, referring to Boyle's law.
Resistance varies in Mike's conducting airways. Using yourunderstanding of respiratory anatomy, explain where in his airwaythe resistance is highest and why.