Structure Flashcards
define oxygenation
absorbtion of O2 into blood stream
define ventilation
excretion of CO2 into air
define perfusion
entire cardiac output getting through lungs (bloodflow)
7 functions of lung
- oxygenation
- ventilation
- perfusion
- sterility
- produce surfactant
- filter blood
- special cell and immunologic functions
what occurs in absence of O2
anaerobic metabolism
composition of air
N2 - 79%
O2 - 21%
CO2 verly low
compostion of alveolar air
N2 - 75%
O2 - 13%
CO2 - 5%
H2O - 6%
what is 1 ATM in mm/hg
760 - wieght of 1 cm of air
how does pressure change with alt?
lower at greater alt.
formula for partial pressure
concentration x total pressure
what does pp of H2O depend on and how does it change
temp and saturation - both increase
what does % H2O saturation represent?
amount of water vapor present for the max possible at that temp
what must all pps add up to
barometric pressure
what is PH2O at 37C
47mmHg
what is PH2O sig?
must be substracted from partial pressure calculations
what are 2 different ways of expressing gas measures
- Standard Temp and Press, Dry (STPD)
2. Body Temp and Press, Saturated (BTPS)
2 main anatomic structures for lungs
- Chest wall
2. diaphragm
what innervated diaphragm
phrenic
inspiration involves what movements of diaphragm
down and out
in what direction do gases move
high to low pressure
what is intrathoracic pressure on inspiration
-5cmH2O
diff. between passive and active expiration
active- push out esp. w rectus abdo
accesory muscles of inpiration
scalens, sternocleidomastoid, traps
what does the pleura do (2)
- glides
2. transmit pressure
