Respiratory Physiology Flashcards
Functions of the lungs
gas exchange
pH maintenance via retention or elimination of CO2
Conversion of ANG1 to ANG2 for blood pressure control
Pressure and volume relationship
inversely related
air will flow from areas —
high pressure to low pressure
Is inspiration an active or passive process?
active
primary inspiratory muscles
diaphragm (phrenic nerve fires –> diaphragm contracts)
external intercostals (elevate ribs –> increase transverse diameter)
external intercostals (evert ribs –> increase AP diameter)
Accessory inspiratory muscles
Sternocleidomastoid
Serratous anterior
Scalenes
Pectoralis
Is expiration a passive or active process?
passive
Muscles for forced expiration
internal intercostals
abdominal muscles
Pressure and volume for inspiration
Volume increases –> pressure in lungs decreases –> air flow from atmosphere into lungs
Pressure and volume for expiration
Volume decreases –> pressure increases –> air flows out
Conducting zone
nasal cavity
pharynx
trachea
bronchus
bronchioles
What is considered the anatomic dead space?
conducting zone; no gas exchange occurs here
volume in conducting zone/dead space
150 mL
1/3 of tidal volume
What is surfactant created by?
Type 2 pneumocytes
What is the alveolar epithelium created by?
type 1 pneumocytes
Volume in the respiratory zone
3L
Does diffusion occur actively or passively?
passively
Diffusion is directly proportional to
pressure difference (P1-P2; AA gradient)
Surface area
temperature
solubility (easier to offload CO2 than to transfer O2 over)