5.2 Pulmonary Flashcards
for gas exchange to occur, we must have WHAT at same place?
1) ventilation (air)
2) perfusion (blood)
what is pulmonary vascular resistance?
the resistance to blood flow going thru pulmonary circulation AND how it is related to R ventricular cardiac output
what happens as R. ventricular output increases? (pumps more out)
resistance to outflow in pulmonary vasculature goes down
the more blood that goes into pulmonary vasculature, the ____ resistance to blood flow
less
as more blood goes into pul. vessels, why does resistance go down?
1) resistance in parallel add receprically
- -so when you have an increae inparallel pathways, total resistance goes down
2) increase in R. cardiac output bc they can distend ( or increase their vessel radius)
increasing cardiac output ____ resistance to bloodflow
decreases
what is physiological dead-space?
anatomic + alveolar deadspace
define alveolar dead-space?
- ventilation but no perfusion
* wasted gas in alveolar, typically due to a clot stopping blood flow
define anatomic dead-space?
conducting pathways blocked so no gas exchange
1) what happens if you have both ventilation and perfusion at same spot?
2) one and not the other?
3) both at different spots?
1) Gas exchange!
2) no gas exchange
3) no has exchange
how can you get vent and perfusion mismatch?
- clots and embolace = vent and no per
* mucus plug or objects inwindpipe= per but no vent
how much alveolar dead-space is in a healthy person?
very very low
what does your body do to an area of no gas exchange over a long period of time?
brachioconstriction!
bc why support air if there is no exchange
what is L to R shunting?
- impacts large area of blood
- when R deoxygenated blood dumps right into the L ventricle
- low O2 and high CO2 in blood
what is hypoxic pulmonary vasoconstriction
something is blocking an airway and you do NOT have ventilation (become hypoxic)
define hypoxic
can’t get enough oxygen
what happens with no ventilation?
O2 keeps getting used but NOT resupplied. So alveolar gas becomes hypoxic and sends a signal to the upstream vessel to vasoconstrict
*hypoxic pulmonary vasoconstriction response
body response to an area of no ventilation?
decrease perfusion
is hypoxic pulmonary vasoconstriction a normal response?
Yes!
*segmented effect
when is hypoxic pulmonary vasoconstriction NOT a normal response?
high altitude with lower partial pressure of oxygen in the atmosphere. This can lead all of your alveolar to read as ‘hypoxic’ thus causing constriction
- global effect
- increase altitude= decrease partial pressure of oxygen
increase altitude= decrease _______ of oxygen
partial pressure
what is edema?
movement of fluid from a vascular space into tissue
filtration forces?
tend to move fluids from capilaries into tissue
*CPH and TOP
reabsorption forces?
movement of tissue fluid into vessels
*COP and THP
what are the types of filtration/reabsorption forces?
pulling and pushing
oncotic vs hydrostatic pressure?
- oncotic (aka osmotic or colloid)= pull
* hydrostatic (aka blood pressure)= push
other names for oncotic and hydrostatic pressure?
- oncotic (aka osmotic or colloid)
* hydrostatic (aka blood pressure)
what happens to plasma proteins in burn injuries?
- drop dramatically
- so if everything else stayed the same the filtration forces would be greater than reabsorption
a lot of circulating plasma proteins means?
more capillary oncotic pressure
*fluid moved from tissues into vessels
the higher the pulmonary capillaries, the greater?
the driving force of fluid thru fenestration (holes) into tissues
What IS oncotic pressure? comes from? common protein?
- comes from proteins= proteins PULL water towards them
- typically albumin in blood/plasma= so draw water into vessels
- PULL fluids
edema causes separation of?
capillary and tissues
what is Fick’s law of diffusion tell? T means?
tells you what is going on, how thick the barrier is between capillary and tissues
*T=thickness, INverse relation
increase in barrier thickness= _____ diffusion
decrease
edema decreases diffusion
does the R or L heart eject more?
eject the same amount!
what is most common cause for pulmonary edema?
- left heart failure (something is going on with left ventricle)
- doesn’t take much of a mismatch to have a drastic result
what is R CO is greater than L CO by one drop of blood (0.1 mL) for each heart beat?
- 1 mL/beat * 80 beats/min= 8mL of blood would back up in the pulmonary vasculature every minute
* *shows how FAST a small change (congestive heart failure) can lead to a back-up of blood leading to an increase filtration leading to edema
what can happento alveoli with pulmonary edema?
- fluid can get into alveoli
- even worse, as fluid pressure increases outside of alveoli it can close off the alveoli sacs
CAD?
coronary artery disease
MI?
mycardial infarction
myopathy
bacterial or viral infection
hypertension
L vent keeps trying to pump blood out, but there is high aortic back pressure
aortic stenosis
L vent works even harder to get stuff out. EVERY time it ejects over time it’ll have to work harder and harder. becomes over worked and starts to dysfunction
regurgitation?
every time it ejects blood, some comes back into ventricle
describe left heart failure?
R CO > L CO
- pulmonary edema
- dyspnea
causes of left heart failure?
1) hypertension
2) weakened L ventircle= CAD, MI, myopathy
3) valve disease= stenosis and regurgitation
describe right heart failure?
L CO > R CO
*peripheral, dependent edeme
causes of right heart failure?
pulmonary hypertension
valve disease
what happen if the left is pumping out more than the R can eject?
causes edema throughout the body
*standing causes ankles to swell and laying down means the lover back will swell
if you hear peripheral edema, you should think?
right heart failure
edema REALLY causes problems with?
gas exchange! at the alveolar/pulmonary capillary interface
