EXAM 4 Flashcards
FICK DIFFUSION EQUATION
K x A x (P2-P1/D)
K= DIFFUSION COEFFICIENT (200,000 GREATER IN AIR THAN WATER)
A= AREA
P2-P1= GRADIENT
D= DISTANCE
TUNA: greater SA and flow
TROUT: Significantly greater thickness
Be able to describe how mammalian respiratory systems moves air from the outside
into the lungs.
INHALATION: muscles contract, volume increases, pressure inside falls so air flows in
EXHALATION: muscles relax, volume decreases, pressure inside rises so air flows out
The diaphragm functions as a thin muscular sheet that controls the regulate the volume inside the chest cavity (separates the chest and abdominal cavities)
Be able to calculate respiratory minute volumes
Respiratory minute volume = Tidal volume (mL) x breathing rate (BPM)
Be able to describe characteristics (4 things) and function of the bird lung that allow it to
perform so well at high altitudes compared to mammals
One way airflow
Large areas of gas exchange
Barrier thickness
countercurrent
Be able to calculate the partial pressure of Oxygen at any altitude given the atmospheric
pressure
@ sea level (760mm Hg)
N= 0.78 x 760
O= 0.2094 x 760
CO2= 0.0004 x 760
Know the 4 things that affect the concentration of a gas in solution
Temperature
Solutes present
Pressure
Solubility
Be able to describe the characteristics of the hemoglobin molecule
tetrameric protein and heme group
sigmoidal binding curve
One binding oxygen causes an increase in affinity for the rest
Be able to describe the hemoglobin binding curve and why it is S shaped. Why is the
shape important for loading and off-loading Oxygen? What is subunit cooperativity?
The hemoglobin binding curve in a S curve because the binding of one oxygen will cause a conformational change and thus increase the likelihood of other oxygen atoms binding. COOPERATIVITY
Be able to compare the affinities of different hemoglobin molecules and myoglobin and
describe them based on their P-50s
(on graph): start at the left and read down
What environmental factors affect the affinity of Hb for oxygen? Which way do they
shift the binding curve? Why are they important to loading and unloading oxygen? Acid
Bohr effect, gaseous Bohr effect
REDUCED AFFINITY (right shift) : increase in temperature
binding of organic phosphates DPG and ATP
decrease in pH (BOHR SHIFT)
increase in CO2 conc.
Why does Myoglobin have a hyperbolic binding curve? What is Mb’s function? Why is
its affinity for Oxygen so high?
single heme group
stores oxygen for working muscles
proximal histidine group helps oxygen bind and it binds more tightly
non cooperative binding
Why is breathing carbon monoxide a problem. How does it affect oxygen transport by
the blood?
Hb has a significantly greater affinity for CO (200x) than for O2
Be able to the describe differences between fetal and maternal Hb and how their
affinities differ. Why is this important?
Fetal has a higher affinity over maternal
Fetal hemoglobin contains 2 alpha and 2 gamma subunits
What other molecules bind to hemoglobin? How do they affect the affinity of Hb for
O2?
CO
How does the blood carry carbon dioxide? What are the pools and their size?
Dissolved in plasma 5%
Bound to hemoglobin 5%
Dissolved in plasma as bicarbonate 90%