Pulmonary Physiology Topics - Dr. Rogers Flashcards
inspiration P and V
V increases when P decreases by 1mmGH (when chest cavity opens)
Interpleural P
less then atmospheric P, (from -5 to -8)
-8 during end of inspiration
Alveolar P
= atmospheric pressure (0) at rest
during inspiration when chest cavity opens = decreases to -1
CAUSES AIR TO COME IN
Transpulmonary P
Palv - Ppl
at rest Ptp = 0 - (-5) = 5
alveolar P at the end of inspiration (most air inside)
alveolar P at the beginning of inspiration
0 for both
alveolar P in the middle of inspiration
alveolar P in the middle of expiration
-1
+1
Ppl at the end of inspiration
Ppl at the beginning of inspiration
- 8
- 5
Ppl at the middle of inspiration
Ppl in the middle of expiration
-6.8 for both
air flow rate is the same as
air flow rate at the middle of expiration
air flow middle of inspiration
Alveolar P
+1
-1
air flow rate at the beginning of inspiration
air flow rate at the end of inspiration
0
Lung compliance and chest wall graph is what
the average of both lung compliance wanting to collapse and the chest wall wanting to spring outward
X : P getting more negative
Y : V getting more positive
FRC Lung compliance and chest wall graph
equilibrium V between lung and chest wall
= when chest wall is at 35% capacity and lung capacity is at 45%
Minute Ventilation
how much air someone is getting every min *NORMAL = 7000ml/min = 7L/min* = Tidal Volume x f f is RR 500ml/br x 14br/min = 7L/min
EMPHYSEMA RV TLC FVC FEV1 FEV1/FVC peak expiratory flow rate
*obstructive increased increased decreased decreased decreased decreased
FIBROSIS RV TLC FVC FEV1 FEV1/FVC peak expiratory flow rate
Restricted decreased decreased decreased some same same decreased
dead space in emphysema
dead space is fibrosis
larger
finding anatomical dead space
1ml per lb of body weight
mine is 118mL of anatomical dead space
alveolar DS
air in alveolus that is inside only doesn’t get blood
Minute Alveolar Ventilation (Valv and V(dot)alv)
amount of air that participates in gas exchange per min Valv= TV-DS = 550mL - 250mL = 300mL V(dot)alv = Valv x f = 300mL x 11br/min = 3.3L/min
EMPYSEMA
compliance
elastic recoil
high
low
FIBROSIS
compliance
elastic recoil
low
high
chest wall and lung compliance graph is what kind of graph
sigmoid so that the middle part is the ideal range
small P change (negative P around lungs) leads to large volume change (volume in the lungs)
* COMPLIANCE = SLOP of line at the point on sigmoid graph
at low lung volume
larger P change needs to happen to increase V of air into lungs (hard to stretch lungs)
at volume around TLC
larger P needed to increase V of air into lungs
hard to stretch lungs
inflating lungs with saline fluid causes what
increases compliance
Hysteresis
the difference in inspiration (needing more P) and expiration (diffusive)
this happens due to LaPlace’s Law
LaPlace’s Law
Surfactant reducing ST in the smallest alveoli more then the larger ones
P to inflate lungs is fibrosis and in emphysema
fibrosis : more P
Emphysema : less P
Fibrosis and obesity
compliance, RR, volume inhaled
lower, higher RR, lower V inhaled
age and compliance
increases
Emphysema and FRC
FRC shifts up the graph
equilibrium of chest wall and lungs are at an increased volume (lung needs less P)
Fibrosis and FRC
FRC shifts downwards
equilibrium is at a lower volume (lung needs more P)
Bronchodilator does what
B2 adrenergic, blocking parasympathetic
air in the alveoli in emphysema
it doesn’t get access to blood for gas exchange
what happens as a side effect of
interdependence = alveoli hold each other open against the lung wanting to collapse
Elastic Forces during inspiration and expiration
work to overcome during breathing from elastic forces (to keep lungs uncollapsed)
Loop on the graph
work to overcome for breathing from resistive forces (in inhale the air)
inhale needs p
exhale reduces P due to diffusion
Work of breathing in restrictive
fibrosis
change in elastic work needed
= increases overall work
*more negative Ppl needed to inhale air in
Work of breathing in obstructive
emphysema
change in resistive work both during inhalation and exhalation
= increase overall work
*higher Ppl needed to exhale air out of lung
change in elastic work (increased) on RR
higher HR
change in resistive work in airflow (increased) on RR
lower HR
