Test Three Flashcards
What is % hemoglobin saturation?
Fraction of all oxygenated hemoglobin in the sample
What kind of oxygen can cross the plasma membranes and enter cells?
Unbound oxygen
As PO2 rises in the blood, % hemoglobin saturation does what?
increases, because more oxygen in dissolved in the plasma
Which is true?
A. PO2 in arterial blood can decrease a lot from its normal max value with a lot of decrease in percent saturation.
B. PO2 in arterial blood can decrease a lot from its normal max value with very little decrease in percent saturation.
B
What are the four factors that shift an hemoglobin saturation curve to the right?
- More acidic solution
- Increase in CO2
- Increase in temp
- Increase inBPG
A shift to the right in a hemoglobin saturation curve means what?
Decreasing the affinity of Hb for O2 at any given PO2
Why do muscle tissues have an increase in oxygen during exercise?
There is an increase in cellular activity leading to an increase in hydrogen molecules. CO2 is a waste product of making ATP from glucose. This increase in hydrogen molecules will cause an increase in pH.
How does CO2 travel?
23% in hemoglobin as carbamino Hb
7% dissolved in plasma
70% as bicarbonate ion
How do the lungs play an important role in regulation of pH?
controlling the rate at which CO2 is eliminated
What increases firing of the periphreal chemoreceptors?
decreased inspired oxygen, decreased alveolar PO2, decreased arterial PO2
If you are poisoned by CO will your breathing rate increase?
No because PO2 does not change, the CO just binds with higher affinity to Hb and less oxygen reaches tissues
What do peripheral chemoreceptors respond to?
DIssolved oxygen not oxygen bound to hemoglobin
When you blow up a pool raft what is happening internally to cause dizziness?
As you are breathing out deep you are ridding your body of CO2 causing an increase in pH. Holding your breath can fix this issue.
T or F:
CO2 and H are more potent stimuli for breathing than O2.
True
What are the peripheral chemoreceptors stimulated by?
Increase in H levels, which is indirectly CO2 levels
What do central chemoreceptors do?
Cells in the medulla oblongata that monitor H concentration of brains ECF
H ions dont cross BBB but CO2 does
What is the normal blood volume in adults?
5 L
How does blood move through vessels?
Bulk flow
Does more blood pass through the systemic than the pulmonary circuit?
No input for one circuit is the same for the other
What happens when aortic pressure excedes that of the ventricle?
The aortic semilunar valve closes
When does the aortic semilunar valve open?
When left vent pressure exceeds aortic
What causes S1 and S2?
S1: closing of the AV valves
S2: closing of the SL valves
Which semilunar valve is most anterior?
Pulmonary valve
What causes mechanical events in the heart?
Electrical events- SA and AV node actionpotentials