Non-respiratory functions Flashcards
What are the pulmonary defense mechanisms?
Air conditioning
Olfaction
Filtration and removal of inspired particles
What are the methods of removal of filtered material?
Cough and sneeze reflexes
Mucociliary escalator
Alveolar macrophages
Other methods of removal or destruction
Particles of what size typically reach the alveoli?
0.3 to 2.0 micrometers
What is the lifespan of alveolar macrophages?
1-5 weeks
What are the non-respiratory functions of pulmonary circulation?
Reservoir for LV
filter to protect the systemic circulation
Fluid exchange and drug absorption
What substances are removed, or mostly removed from the blood by the lungs?
Some prostaglandins (E1, E2, F2-alpha)
Leukotrienes
Serotonin
ATP and AMP
What happens to bradykinin in the blood in the lung?
Mostly inactivated
What happens to angiotensin I in the blood at the lung?
Mostly converted to angiotensin II
What are the effects of aging on the mechanics of breathing?
Calcification of costal cartilages
Increased chest wall stiffness
Stiffness of the diaphragm
Stiffening of CT supporting the lungs
Increased alveolar diameter
Decreases surface for exchange
Progressive enlargement of the respiratory bronchioles and alveolar ducts
Decreased respiratory muscle strength and endurance
What is the typical decline of gas exchange related to age?
Decreases by 0.5% per year
What is the decline of PaO2 after 60 yo?
Declines by 1 torr/yr
