L16;C6 Flashcards
What is Dalton’s law?
The total pressure and sum of all partial pressures of all gases in a mixture
What is SATP at sea level?
760mmHg
How do you find PP?
Barometric pressure x [fractional]
What is Henry’s law?
amount of dissolved gas in a liquid is proportional to its partial pressure
What do diffusion rates depend on?
- pressure differences
- solubility of gas in fluids
PP is ____ in capillaries due to high pressure gradient
High
What does the pressure gradient cause with respect to diffusion?
It causes diffusion of O2 into and CO2 out of tissues
What is higher in tissues? Oxygenated blood or CO2?
CO2
Greater surface area= _______ diffusion
Greater
With respect to diffusion constant, gases that have high what have high diffusion constant?
Gases that have high solubility have high diffusion rate
How much of the bottom lungs are perfumed with blood?
1/3
What is poor about the top 2/3 of surface area of the lungs?
It’s is very bad at any gas exchange
Pulmonary arteries have _____mmHg of CO2
Alveolar PCO2 have _____mmHg
46
40
What does the 6mmHg difference permits comparing pulmonary and alveolar PCO2?
This permits diffusion, it is 20x greater than O2. This allows diffusion despite low gradient
PP dictates diffusion. If PP is lower, what happens to diffusion?
When PP is lower, there is less diffusion
As exercise intensity increases, you go from _____ difference to _____
Lower, higher
More O2, _____ partial pressure
Increased
What are four factors that dictate the maximum amount of O2 blood can carry?
- Based on Hb content
- Hb is 99% saturated at rest
- Lower saturation with exercise
- Less than 2% is dissolved in plasma
People with small stature allow for arterial ________ _______
Enduced Hypoximia
What does Anema do?
It decreases Hb, and decreased O2 Capacity
For every 1mmHg increase, _____ O2 dissolves in plasma
0.003ml
Where is there higher saturation of Hb in the body? Why? Where is it lower?
There is higher saturation in the arteries and lungs so it can be carried and used. It is lower in the muscles
Explain the off loading portion of Hb saturation curve
This is where smaller changes in PP such as metabolism increases which results in large changes in saturation
Explain the unloading phase off the curve
This is where saturation changes with small amounts of PO2 allowing for O2 to unload to tissues easier.
What causes a right shift in saturation curves?
- increase in 2,3DPG
- Temperature increases
- decrease in O2
What causes a shift to the left?
- increase in pH
What is the DPG caused by?
It is a by product of glycolysis
Explain the role of bicarbonate with respect to O2 and Hb
H+ binds to Hb buffering it. This triggers a Bhor effect and it eventually decreases movement of O2 associated with Hb
With regards to carbaminohemoglobin, when you increase PCo2, what does this cause (with Hb binding) and what happens when it decreases?
When PCo2 increases—> it is easier Co2-Hb binding
When PCo2 decreases—> it is easier Co2-Hb dissociation
What is the haldane effect?
Hb interaction with O2 reduces its ability to combine with Co2
This aids with releasing Co2 in the lungs
How many molecules can myoglobin bind? Hemoglobin?
Myoglobin—> 1 molecule
Hemoglobin—> 4 molecules
What is the curve difference between myoglobin and hemoglobin? Why is it like this?
Hb is significant due to it having more binding sites, myoglobin stays the same and has a relative exponential increase due to it only have 1 binding site
What is the relationship between Myoglobin and Hemoglobin?
Hemoglobin is diffusing O2 into muscles, then the Myoglobin facilities the O2 into the muscle for use
What is myoglobins influence and roles (3)
- o2 content of blood
- Blood flow
- Local conditions
What is CO2 removal driven by?
This is driven by PCO2 gradient, blood PCo2 low, tissue (muscles) Pco2 is high
Ventilation requires coordination between ______ regulation of ________ ventilation
Involuntary, pulmonary
What three things does the respiratory Center have?
- inspiratory, expiratory
- located in brain stem
- established rate and depth of breathing signals
What is the most potent stimulus for breathing nervous action?
Co2
Wheat are central chemoreceptors stimulated by? What are their functions?
Stimulated by the increase in Co2 in cerebrospinal fluid.
They also increase rate of breathing and removes excess Co2 from body
What are peripheral chemoreceptors? Where are they located?
These are in aortic body and bifurcation of the carotid arteries, they are sedative to blood Po2, PCO2 H+
What are mechanoreceptors?
These deal with excessive stretch, they reduce breathing
What is frank starling law?
stroke volume of the heart increases in response to an increase in the volume of blood in the ventricles, before contraction
What is ficks law?
Diffusion occurs from high [] to low []
