Flashcards in Resp - Respiratory Mechanics Deck (65)
Loading flashcards...
1
muscles of inspiration
diaphragm (75%)
external intercostals (25%)
2
accessory inspiration muscles
scalenes (raise rib 1/2)
sternocleidomastoid (raise sternum)
3
muscles of expiration (active)
abdominal wall
internal intercostals
4
causes for difficulty inspiring
scar tissue
reduced surfactant
mucous
fluid
5
causes for difficulty expiring
emphysema
6
point where laminar --> turbulent
reynolds # > 2000
7
conditions where turbulence likely occurs
velocity high
radius high
8
Reynold's number
Re = 2rvd/n
9
Ohm's law (airflow)
F = delta P/R
10
Poiseuille's law
R = 8L(viscocity)/pi(radius^4)
11
Poiseulle's law take away
smaller the airway, greater the R (reduce r by 50% increase R x 16)
12
site of most airway R (+why)
medium sized bronchi
smaller than large (up R) and in series rather than parallel (smaller ones in parallel)
13
factors increasing resistance
turbulent flow
small radius
lung volume decreasing
bronchial SM contraction
gas density elevated (SCUBA)
forced expiration
14
causes of bronchoconstriction
allergy
mucous, airway collapse
PNS during relaxed state (Ach on muscarinic)
low CO2
15
causes of bronchodilation
SNS
*Epi (beta-2)
*CO2 up
16
forced exhalation
PA drives air out
PA = Pip + P elastic recoil
further from alveoli, less recoil
exhaling air hits R, loses P
EPP
17
equal pressure point
when Pairway = Pip
if Pip > Pairway --> collapse
(EPP @ cartilage for healthy people)
18
emphysema and forced expiration
alveoli have lost elastic recoil
PA is lower, EPP happens closer to alveoli, compression of airway
19
chronic obstructive pulmonary disease (diseases)
asthma
chronic bronchitis
emphysema
20
emphysema mech
1. irritation --> many macs, release trypsin
usually alveoli release antitrypsin (but too many macs to fight)
2. breakdown of alveolar walls
3. down recoil, collapse smaller airways
21
pulmonary function tests
spirometry
lung vol measurement
diffusion capacity for CO
arterial blood gases
22
tidal volume (TV)
V in or out in quiet resp
~500 ml
23
inspiratory reserve volume (IRV)
extra V can be inspired after quiet inspiration
24
expiratory reserve volume (ERV)
extra V can be expired after quiet expiration
25
inspiratory capacity (IC)
max V in after quiet expiration (TV + IRV)
26
vital capacity (VC)
max V in after max expiration (IRV + TV + ERV)
~ 4800 ml
27
residual volume (RV)
min air remaining in lungs after max expiration
28
functional residual capacity (FRC)
V in lungs after quiet expiration (ERV + RV)
29
total lung capacity (TLC)
max V lungs can hold (VC + RV) ~6000 ml
30
