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Test 8
questions from Dr P Kidney folder
44
Physiology
Professional
12/12/2010

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Term
when the forces resisting stress are decreased, compliance is___
Definition
increased
Term
severe emphysema increases/decreases compliance of lung tissue and increaes/decreases elastance
Definition
increases; decreases
Term
Interstitial fibrosis, pulmonary edema, deficiency of pulmonary surfactant increases/decreases compliance of lung tissue.
Definition
decreases
Term
What is the PO2 of dry oxygen?
Definition
760 mmHg
Term
What is PO2 on humidification?
Definition
713 mmHg
Term
What is PO2 entering alveoli?
Definition
673 mmHg
Term
What is the Bohr effect on Hb?
Definition
kicks off oxygen
Term
What is the haldane effect on Hb?
Definition
kicks off CO2
Term
what is the diaphrag, innervated by
Definition
phrenic nerve
Term
why is inspiration an active process, even at rest?
Definition
It involves muscle contractions, which require energy
Term
Expiration is a passive process (muscles are relaxing) What is the driving force?
Definition
The muscles relax, the lungs are elastic which decrease the volume in chest cavity. This increases intrapulmonary pressure, and forces air out.
Term
If there is low ventilation in an area and therefore high levels of CO2, what happens to airways?
Definition
dilate to increase air flow
Term
if there is low ventilation in an area of the lung and there are low levels of oxygen, what happens?
Definition
vasoconstriction of blood vessels to lower the blood flow
Term
if there is low blood flow (perfusion) what are the oxgyen/CO2 levels like?
Definition
high levels of oxygen and low levels of CO2
Term
if there is low blood flow, what do airways and blood vessels do?
Definition
airways constrict to restrict air flow and blood vessels dilate so there is higher blood flow
Term
how do you calculate the partial pressure of a gas?
Definition
take the concentration of the gas and multiply it by the pressure on the gas
Term
which component of atmospheric air has the highest partial pressure and why?
Definition
nitrogen--largest concentration of air
Term
What happens to nitrogen when breathed in and why?
Definition
it's breathed back out bc it is insolubile in water at pressures and temps associated w human body
Term
what percent of oxygen is dissolved in plasma?
Definition
1.5 (very small)
Term
what percent of oxygen is bound to hemoglobin
Definition
98.5
Term
Where is the oxygen when you determine partial pressure?
Definition
physically dissolved in plasma (1.5% total oxgyen)
Term
when oxygenated blood goes by tissue, where does the oxygen that's in the plasma go and why?
Definition
from arteriole blood into tissue
partial pressure difference
Term
why does the affinity for oxygen on hemoglobin change?
Definition
PO2>>tissue due to partial pressure differences
partial pressure of oxygen in plasma drops
Oxygen leaves Hb and goes into plasma
Term
what is the normal PO2 at pulmonary capillaries?
Definition
100 mmHg
Term
Blood leaving the lungs: Hb is ___ % saturated
Definition
98.5
Term
At PO2 of 40 mmHg, how much percent of oxygen bound to hemoglobin was delivered to tissue?
Definition
about 25% (because 75% of Hb is sitll saturated)
Term
What is the plateau phase of the Hb Dissociation curve?
Definition
at 60mmHg to 100mmHg
when the PO2 of alveoli drops significantly, but the percent of oxygen bound to Hb doesn't drop significantly
Term
if you were looking at a very active tissue, what part of the Hb dissociation curve would you look at?
Definition
left side
0mmHg-40mmHg
Hb is becoming unsaturated very quickly
Term
which is more soluble in water/plasma? Oxygen or CO2
Definition
CO2
Term
what percent of CO2 is dissolved in plasma
Definition
10%
Term
what percent of CO2 is bound to Hb?
Definition
30%
Term
where does remaining 60% of CO2 go?
Definition
forms bicarbonate (and reaction also gives of H+)
Term
what happens to the bicarbonate produced from CO2 (in the RBC)
Definition
it diffuses out of the RBC and is exchanged for CL-
Term
What happens to the H+ that was given off in the reaction of CO2 to bicarbonate?
Definition
it binds with Hb
--Hb acts as a buffer
and kicks off Oxygen for tissues to use
Term
finish the progression...
the more the CO2...
Definition
the more the H+ and the more Oxygen is kicked off

called Bohr effect
Term
If there is more CO2 present, more H+ present, and a higher temperature, which way does the Hb-Dissociation curve shift?
Definition
down and to the right
Term
A shift of the Hb-Dissociation curve of down and to the right does what to Hb-Oxygen saturation?
Definition
enhances oxygen release from Hb
Term
What chemical is the main driving force for controlling respiration?
Definition
CO2
Term
What are peripheral chemoreceptors?
Definition
Aortic Arch and Carotid Bodies
secondary chemoreceptors
sensitive to fall in arterial O2 below 60 mmHg
Term
What are central chemoreceptors?
Definition
found in the brainstem
main driving force of respiration
sensitive to CO2
Term
In the brain, if CO2 increases, then H+_____
Definition
increases very quickly
Term
There are vew buffers in the brain so when there are high levels of CO2_____
Definition
there are high levels of H+, which change the pH and the central chemoreceptors adjust respiration
Term
What is the main driving force of respiration in a patient with COPD
Definition
Oxygen levels (peripheral chemoreceptors)
Term
Which center in the brain increases ventilation?
Definition
Medullary Respiratory Center
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