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52 Cards in this Set

  • Front
  • Back
Formula for PVR
PVR = (Ppa - Pla)/ CO
During lung inflation (inspiration) extralveolar vessels _ while alveolar vessels _
Extralveolar vessels expand while alveolar vessels collapse
Decreased alveolar O2 (hypoxia) causes vasodilation or vasoconstriction
Decreased CO causes increase or decrease in PVR
2 normal mechanisms for increase in pulmonary blood flow during exercise (or increased CO)
Recruitment and distention
Lung volume increased PVR increased or decreased
Zone 1 of the lung

PA>Pa>Pv - collapse of vessels, low blood flow
Zone 2 of lung
Mid lung
Most optimal matching of ventilation and perfusion

Zone 3 of lung
Base - excess of blood flow, not enough ventillation
Alveolar ventilation
Volume (per minute) of fresh air moving into alveoli for gas exchange

Total ventilation - anatomical dead space
The amount of blood (per minute) perfusing pulmonary capillaries
Ventilation and perfusion are highest at _ and lowest at _
Highest - BASE

Lowest - APEX
V/Q ratio is high at _ and low at _
High - APEX

Low - BASE
There is wasted ventilation at _ and wasted perfusion at _

Ficks law of diffusion
V gas = A/T * D * (P1-P2)
D the diffusion constant is primarily determined by _
Solubility of gas
What can diffuse faster across the capillary membrane - CO2 or O2
Which variable in Ficks law of diffusion changes with the disease state
A/T ratio - area changes with emphysema, thickness changes with pneumonia, fibrosis
V/Q ratio of infinity means _
There is a block in pulmonary circulation (pulmonary embolism)
Is ventillation higher at apex or base
Is perfusion higher at apex or base
Is V/Q ratio higher at apex or base
PO2 is higher at apex or base
PCO2 is higher at apex or base
O2 concentration is higher at apex or base
CO2 concentration is higher at apex or base
pH is higher at apex or base
Higher at apex (not enough CO2)

Lower at base (low CO2)
Deoxygenated blood enters arterial blood from _
Bronchial circulation and Thebesian veins (venous admixture)
Anatomic shunting of blood may occur through AV fistulas or other direct connections that bypass the alveolus will reduce _ and increase _
Reduce PaO2 and increase PaCO2 - cause hypoxia and hypercapnia
Presence of anatomical shunt can be confirmed by _
Having patient to breath 100%O2 - low PO2 WILL NOT be corrected if the problem is anatomical
If the partial pressure of gas doesnt build up to match alveolar pressure the gas is said to be _
Diffusion limited - cant diffuse across the membrane fast enough to equilibrate partial pressures
If the gas builds up rapidly in blood and equilibrates with alveolar partial pressure the gas is called_
Perfusion limited
N2O - perfusion limited or diffusion limited
Perfusion limited
CO - perfusion limited or diffusion limited
Diffusion limited
In the normal individual O2 and CO2 - perfusion or diffusion limited?
Neither - somewhere in between, do not cause problems in normal individual
Is most oxygen bound to hemoglobin or dissolved in plasma
Bound to hemoglobin
Most CO2 is carried in the form of _ and the rest?
bicarb - HCO3, rest - as carbamino compounds and dissolved in plasma
Within the cells oxygen is carried by _
Myoglobin and dissolved
PO2 is determined by bound or dissolved oxygen
Amount of oxygen dissolved in plasma
Saturation is _
percent saturation of hemoglobin with O2
Normal arterial saturation
Normal venous saturation
The total amount of oxygen carried by blood (21 ml/dl)
P50 is the PO2 where 50% of hemoglobin is saturated
A shift of Hb curve to the right means _
Decreased O2 affinity
Which factors whould shift Hb curve to the right
Increased temperature, DPG, PCO2, H+
Which conditions would shift the O2 dissociation curve down
Anemia, CO poisoning
Bohr effect
CO2 and H+ reduce affinity of hemoglobin for O2 and shift P50 to the right - this helps in unloading of O2 at tissues
Haldane effect
Presence of higher PO2 in the blood helps unloading of CO2 at lungs
CO2 is transported in 3 forms - name them

Carbamino hemoglobin

Bicarb - MOST of the transport
Bicarb is formed at _
HCO3 is exchanged for plasma _ - this is called _
Cl - chloride shift