Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
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
|
Vasoconstriction
|
|
|
Decreased CO causes increase or decrease in PVR
|
Increase
|
|
|
2 normal mechanisms for increase in pulmonary blood flow during exercise (or increased CO)
|
Recruitment and distention
|
|
|
Lung volume increased PVR increased or decreased
|
Increased
|
|
|
Zone 1 of the lung
|
Apex
PA>Pa>Pv - collapse of vessels, low blood flow |
|
|
Zone 2 of lung
|
Mid lung
Most optimal matching of ventilation and perfusion Pa>PA>Pv |
|
|
Zone 3 of lung
|
Pa>Pv>PA
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 |
|
|
Perfusion
|
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 _
|
APEX
BASE |
|
|
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
|
CO2
|
|
|
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
|
Base
|
|
|
Is perfusion higher at apex or base
|
Bse
|
|
|
Is V/Q ratio higher at apex or base
|
Apex
|
|
|
PO2 is higher at apex or base
|
Apex
|
|
|
PCO2 is higher at apex or base
|
Base
|
|
|
O2 concentration is higher at apex or base
|
Apex
|
|
|
CO2 concentration is higher at apex or base
|
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
|
97%
|
|
|
Normal venous saturation
|
75-80%
|
|
|
Content?
|
The total amount of oxygen carried by blood (21 ml/dl)
|
|
|
P50?
|
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
|
Dissolved
Carbamino hemoglobin Bicarb - MOST of the transport |
|
|
Bicarb is formed at _
|
RBC
|
|
|
HCO3 is exchanged for plasma _ - this is called _
|
Cl - chloride shift
|
