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24 Cards in this Set

  • Front
  • Back
what are some of the nonrespiratory functions of the respiratory system?
-route for water loss and heat elimination
- enhances venous return
- contributes to maintenance of normal acid-base balance
- enables vocalizations
- defends against inhaled foreign matter
- modifies, activates, and inactivates materials
-nose: organ for smell
what structures help keep the trachea open?
cartilaginous rings
what controls the smooth muscle surrounding the bronchioles from terminal to respiratory bronchioles?
it is regulated by the autonomic innervation, but is also sensitive to hormonal and local neurotransmitters to dialate and constrict those bronchioles
what is the function of the pores of Kohn?
the pores of Kohn allow 1 alveolus to move gas to another to allow for collateral ventilation
the walls of alveoli are composed of which type of cells?
single layer of flatten type I alveolar cells
what do type II alveolar cells do and where are they found?
type II alveolar cells are found in alveolar epithelium and secerete pulmonary surfactant, which facilitates lung expansion and keep them open
how many pairs of curved ribs are there in the outer chest wall?
there are 12 pairs of curved ribs which join sternum and thoracic vertebrate (protection)
what is the function of the pleural sac?
the pleural sac separates each lung from thoracic wall (chest wall)
the pleural cavity is inside the plural sac and the pleural surfaces secrete fluid into this cavity which allows for exanpsion and closing easily, prevents pain
what are the membranes on either side of the pleural cavity?
visceral pleura (inner) is attached to the lung and other internal organs, and the parietal pleura (outer) is attached to chest wall
what is atmospheric pressure?
atmospheric pressure is the P produced by weight of the air on objects on surface of Earth, 760 mmHg at sea level
what is the average intrapleural (intrathoracic) pressure?
the P in the pleural sac averages 756 mmHg at rest, also written as -4
what is the transmural P gradient across the lung wall?
it is the net outward P differential between intra-alveolar P and intrapleural P
the gradients pushes lungs outward when intra-alveolar P is greater than P outside alveoli (intrapleural P), also helping to keep lungs open
what is the transmural P gradient across the lung wall?
intra-alveolar P minus intrapleural P, differential is 4 if it has equilibrated with atmospheric P
what is the transmural P gradient across the thoracic wall?
atmospheric P minus intrapleural P (760-756=4) pushing in
which has a greater effect transmural P across lung wall or thoracic wall?
the transmural P across the lung wall has a greater effect than the structures (thoracic wall) cause it's soft tissue so lungs stay open even though differentials are equal
when the intra-alveolar P is less than atmostpheric P what happens to air?
air enters the lungs
when the intra-alveolar P is greater than the atmospheric P what happens to air?
air exits the lungs
what is Boyle's Law?
P1V1 = P2V2
intra-alveolar P changes according to which law?
Boyles Law
what are the muscles of active expiration?
internal intercostal muscles, and abdominal muscles
what are the major muscles of inspiration?
external intercostal muscles and diaphragm
what are the accessory muscles of inspiration?
sternocleidomastiod and scalenus
what does expansion of thoracic cavity do to intrapleural P?
it decreases it (754 mmHg), lungs drawn into area of lower P, they expand, increas in lung volume lowers intra-alveolar P below atmospheric P, P gradient: air enters lungs
what happens to intrapleural P during expiration?
intrapleural P increase: lungs are compressed