SORU: aşağıdaki parçaya göre cevaplayınız
It is clearly pointed out in the passage that only a small amount of the air inspired during normal respiration ----.
The ultimate importance of the pulmonary ventilatory
system is to continually renew the air in the gas
exchange areas of the lungs, where the air is in
proximity to pulmonary blood. These areas include
the alveoli, alveolar sacs, alveolar ducts and
respiratory bronchioles. However, during normal
quiet respiration, the volume of air is only enough to
fill the respiratory passageways down as far as the
terminal bronchioles, with only a small portion of the
inspired air actually flowing all the way to the alveoli.
Some of the molecules in the inspired air travel the
final short distance to the alveoli through diffusion,
but most never reach the gas exchange areas of the
lungs, instead going to fill respiratory passages
where gas exchange does not occur, such as the
nose, pharynx and trachea. This air is called dead
space air because it is not useful for the gas
exchange process; the respiratory passages where
no gas exchange takes place are called dead space.
On expiration, the air in the dead space is expired
first, before any of the air from the alveoli reaches the
atmosphere. Therefore, the dead space does not aid
in removal of the expiratory gases from the lungs.