Physiology Flashcards
your FEV1/FVC ratio has to be under _% to be diagnosed with COPD
70
why is gas exchange affected in emphysema?
destruction of the alveoli
pulmonary compliance is __creased in emphysema; why?
increased
lose elasticity of tissue so its easier for the lung to expand
emphysematous lungs have a problem with compliance/recoil
recoil
dynamic airway compression is more likely to occur during active expiration/inspiration
active expiration
raising intrapleural pressure which will compress the airways
what chemoreceptors are affected in anxiety?
central
autonomic
2 components of COPD
emphysema and bronchitis
pathophysiology of airways in COPD
fixed airway obstruction and decreased surface area for gas exchange
pathophysiology of airways in fibrosis
reduced pulmonary compliance and impaired gas diffusion
inc alveolar surface tension….
surfactant in newborns
reversible airway obstruction…
asthma
pathophysiology of the SoB in LHF?
reduced pulmonary compliance because of oedema and impaired gas diffusion as a result
according to the O2/haem dissociation curve, how much does O2 need to drop before the Hb drops too
O2 needs to decrease ALOT before Hb decreases
what effect does fibrosis have on an ABG?
affects the diffusion of gases esp oxygen as it thickens the membrane
which diffuses more readily: CO2 or O2?
CO2
which gas will be most affected in pulm fibrosis?
O2 as CO2 is more readily diffusible through the lungs
what cause the tingling and numbness in an anxiety attack?
low calcium as a result of resp alkalosis
it binds to albumin and becomes biologically inactive
how does calcium exist in the blood?
free unbound
bound to albumin
functional residual capacity constitutes about _% of the lung capacity
50
a low PO2 causes pulmonary vaso____
constriction
larger airways are supplied by the pulm/systemic circulation
systemic
does B2 or B1 agonists cause bronchodilation?
B2
2 lungs 1 heart
surface area for gas exchange remains constant in the absence of disease T or F
F
it increases with exercise etc
decreased lung diffusion capacity indicates what about the alveoli?
decreased surface area of the alveoli due to disease
examples of restrictive lung disease?
pulm fibrosis
sarcoidosis
what works faster: digoxin or ACEi?
ACEi
digoxin takes 24hrs so not good acutely
what cardio drugs are NOT given in heart failure
calcium channel blockers
Tx acute heart failure
IV furosemide + nitrate infusion
MoA nitrates
venous dilatation which reduces preload
PO2 is normal/low/high in an anxiety attack
normal
breath sounds are ___ed in pneumothorax
decreased/nil
compensation is fast/slow in resp acidosis
slow
when would you get a low pO2 in COPD?
if you have an acute infection eg acute bronchitis
resp alkalosis with a low pO2
altitude
resp alkalosis with a normal pO2
anxiety
the problem is within the airways or lung parenchyma in restrictive lung disease
lung parenchyma
ketone bodies are acidotic/alkalotic
acidotic
what kind of crackles would you hear with fluid in the lungs
fine
what drug is prescribed to help with anxiety in terminal illness
lorazepam
