work of ventilation 2 Flashcards
(14 cards)
compliance elastic work :
1-force to – lung against its elastic properties ( — fibres and — )
frictional/resistive work ( non - elastic ) :
2- force to overcome air-flow — ( force to – air through airways)
expand
elastin fibres and surface tension
resistance
move
airway resistance:
at rest , airway resistance to flow is —
- normal pressure difference between mouth and alveoli is approximetly – cmH20 which is — to give normal restinf tidal volume approximelty —
= increased resistance requires a – pressure gardient to drive airflow same tidal volume of appriximately 500 ml
low
1
sufficient
500 ml
greater
airway resistance and diametre:
we have to understand how diematre is linked to flow resistance
- hagen - posiolle low
- relates — ( volume transported per time unit) to airwat — and to – the air is transported
- applies to scenario of — in a —- tube
flow rate v/t = triangle P x radius x r power 4 / 8nl
- note the string influecne of airwat radius
flow rate
radius
distance
laminar flow
striaght cicurlar
airway resistance :
2 main components determine the airway resistance
1- — of the airway aka — and the – air has to travel :
- lung –
- bronchial smooth muscle–
- – of the mucous lining and submucosa
- — layer
2- flow —/— as — vs —
diametre
cross sectional area
distance
volume
tone
thickness
mucous layer
type/pattern
laminar vs turbulent
airway resistance and cross sectional area of bronchial tree:
- an indiviual bronchiole obv has a far – radius than trachea
- however the large number of bronchioles mean overall the airway —
- therefore , resistance in trachea is — than bronchioles
smaller
widens
higher
increasing lung volume increases the airway —
therefor :
resistance to air flow — with increasing volume ( inspiration ) —> airway –
resistance to air flow — with decreasing volume ( exhalation ) –> airway —/–
diametre
decreases
expanded
increases
contracts/compressed
intrisinc control of smooth muscle tone by chemical mediators :
- — degrnaulation release of — and — mediators causes —
- — exerts direct effect on smooth muscle :
–> when raised —
—> when lowered —
masy cells
histamines
inflammatory
bronchocontriction
c02
bronchodilation
bronchocotrsition
factors influencing secretions:
- secretions of — glands and — cells that line respiratory system
–> 5-10um thicker inner layer more – to allow – action and upper layer more – to – particles
- these secretions controlled by — nervous system reflexes and local — stimualtion
–> decreased by –
—> increaded by –
seromucous
goblet cells
watery
cillary action
visicid
trap
parasympathetic
local chemical stimualtion
atropine
bronchitis
airway resistance and pattern of flow:
- pattern of airflow linked to —
- we differentiate between laminar and tubulent flow
- laminar flow is a — flow ( smooth ) and is – ordered so not —
- – velocities and – diamteres promotes tubulences example:
- tubuelences in upper airway during excersise
- empty nose syndrome/paradoxical obstruction
- no turbulence in — since velocites is low and diametre low
velocity
streamline
well
choatic
hgih
large
bronchioles
sites of airway resistance:
- greatest resistance in – airways and less in — in normal indiviuals
- 1/2 total airway resistance in — , – , –
- below — : 80% Raw in – and —
- less than 20% Raw in — <2mm diametre
large
ssmall
nose pharnyx lanryx
below larynx
trachea and main bornchi
brocnhioles
asthma:
- — disease characterised by —
- treat w – and —
- —- relaxes smooth msucle and – airways
- cortisoteriods reduces — and reduces —
respiratory
lung inflammation
bronchodilators and cortisetriods
bronchodilators
widdens
inflammation and reduces secretion
chronic obstructive pulmonary disease:
1- chronic bronchitis
- excess production of — which results in – and production of —
- treat by cessation of — , — if bacterial , —
2- emphysema :
- loss of — due to uncontrollable action of —
- lung elastase in normally inhibited by — ( ie. alpha 1 anti trypsin for which 1 in 4,000 have genetic deficincy )
- treat by cessation of – , avoiding — , lung — , — therpay
mucus
cough
sputum
smoking , antibitoics , bronchodilators
elastic tissue
protoleytic enzymes
antiproteases
smoking , infants , lung transplant , gene therapy
pulmonary fibrosis:
- formation of excess —- in the lungs
- — lung disease and – compliance
- causes:
idopathic
inhalation of – as coal dust or asbestos
certain – as bleomycin
disease as —
- treatment:
- immune – agents as –
- — supplemetnation to improve QOL
- lung —
fibrous connective tissue
restrcitve
reduces
pollutant
medications
scardosis
suppressive
cortisteriods
oxyygen
trnasplanation
classification of respiratory disease into obstructive or restrictive:
1- obstrictive respiratory disease as — , — :
interferes w the – of air through airways
—- flow resistive work
— elastic work
decreases — but not — ( or only slightly ) so ratio —
2- restrictive respiratory disease as —
interferes w the ability for lungs to — so compliace —
— elastic work
—- flow resistive work
— FEV1 and FCV and ratio remains —
COPD , asthma
movement
increases
no effect
FEV1
FCV
decreased
pulmonary firbosis
expand
decreased
inceeases
no effect
FEV1 and FCV
normal
