Lecture 2 Pulm physio Flashcards
respiration is the series of exchanges that leads to the uptake of ____ by cells and the release of ___ to the lungs.
cellular respiration is the use of ____ in _____
O2, CO2;
O2, ATP synthesis
Dalton’s law: the total pressure of a mixture of gases is equal to the ____
sum of the individual gas pressures;
ie Patm (760) * % gas in atmosphere = P(gas in atmosphere)
fick’s law of diffusion:
3 things that are typically constant and affect rate of diffusion:
1 thing that changes and thus determines diffusion rate
diffusion distance, molecule size, temperature;
pressure gradients
boyle’s law:
the pressure and volume of a gas in a system are ____ related
inversely
if diaphragm contracts, thoracic cavity volume ___ and the pressure ____. air thus flows ____
increases, decreases, in (ie inspiration)
diaphragm is relaxed: thoracic cavity volume ___ and the pressure ____. air thus flows ____
decreases, increase;
out
grahm’s law:
for a gas dissolved in a liquid, the rate of diffusion is proportional to its _____ and is inversely proportional to what?
proportional to solubility in liquid;
inversely proportional to square root of molecular mass
which is more soluble in water, out of CO2 and O2? Which thus has a greater partial pressure in plasma? Which needs less of a pressure gradient for diffusion?
CO2, CO2, CO2
O2 is mostly transported in blood as:
CO2 is transported as:
bound to Hb;
HCO3-
the intrapleural pressure is always ____ than the alveolar pressure
lower
pulmonary blood vessels ____ when hypoxic.
vasoconstrict
Hypoxic vasoconstriction of pulmonary vessels causes blood to be diverted to the “good alveolus”. this causes an ____ in O2 saturation/partial pressure
increase
when a person is standing, blood flow is ____ at the base (zone 3) and ____ at the apex (Zone 1). ventilation is greatest at the ____ and lowest at the _____
highest, lowest;
base, apex
Normal V/Q ratio is ___. At zone 1 (apex), the V/Q ratio is ____ due to a larger decrease in _____. At zone 3 (base), the V/Q ratio is ____ due to a larger increase in _____.
0.8;
increased, perfusion;
decreased, perfusion;
At the gas exchange area, there is a ____ pressure gradient for O2 than CO2. Which diffuses faster? Why?
larger; CO2, better solubility in plasma
hypoxia is a decrease in ____.
hypoxemia is a decrease in _____.
O2 delivery to tissue;
decreased partial pressure of O2
hypoxia causes synthesis of ____ and production of more _____
EPO, RBCs
an increase in ACE-BAT causes a ____ shift of the Hb-O2 dissociation curve
right
increase in ACE-BAT causing a right shift: A = C = E = B = A= T =
A = acid C = CO2 E = exercise B = 2,3 BPG (DPG) A = altitude T = Temperature
a shift to the right of an Hb-O2 saturation curve corresponds with a _____ in affinity of Hb for O2. this causes an increase in ____ of O2 from arterial blood to peripheral tissues
decrease, unloading
2,3-DPG is increased during chronic _____ ( ie at high ____). this ____ the binding affinity of O2 for Hb
hypoxia, altitude;
lowers
diffusion capacity ____ during exercise due to :
increase in number of _____ participating in diffusion, _____ of alveoli and capillaries, ____ the diffusion distance;
improved V/Q ratio in the ____ of the lungs due to increased ____ to the area
increases;
capillaries;
dilation;
lowering;
apex, blood flow
A-a gradient refers to the difference in what?
Alveolar O2 (PA) - arterial O2 (Pa)
normal A-a gradient causes of hypoxemia: (2)
high altitude, hypoventilation
Increased A-a gradient causes of hypoxemia: (3)
V/Q mismatch, diffusion limitation, R to L shunt
a decrease in cardiac output causes (hypoxia/hypoxemia);
anemia causes (hypoxia/hypoxemia)
hypoxia, hypoxia (CO and CN poisining also causes hypoxia)
3 forms that CO2 is transported in the blood
HCO3- (majority), Carboxyaminohemoglobin, Dissolved
Haldane effect: increase in the concentration of ____ will displace ____ from Hb
CO2, O2 (and vice versa)
Haldane effect:
thus, if too much O2 is given to a patient with COPD, there is an increase in plasma ____ and ____ can occur
CO2;
acidosis
what is anatomic dead space? what is physiologic dead space?
normally, how do they relate?
anatomic = volume of air present in conducting airways
physiologic = volume of lung which doesn’t participate in gas exchange (ie not perfused)
normally physiologic = anatomic
compliance is a measure of ______ and is equal to ____ divided by change in ____. what is the opposite of compliance?
distensibility;
volume, change in pressure;
elastance
what is the V/Q ratio in airway obstruction?
what is the V/Q ratio in blood flow obstruction (ie pulmonary embolus)?
O;
infinity
The _____ center is located in the lower pons and _____ inspiration
apneustic;
stimulates
The ____ center is located in the upper pons and _____ inspiration
pneumotaxic;
inhibits
the central chemoreceptors are located in the _____. THey are sensitive to changes in ___ and ____ of CSF
medulla;
pH, CO2
The peripheral chemoreceptors are located:
They are sensitive to changes in what?
carotid and aortic bodies;
changes in pH, CO2, and O2
the chemoreceptors in general are most responsive to changes in ____
CO2
