Lecture 1 Flashcards
What is renal clearance?
a volume of plasma that is cleared of a compound per unit time
What is free water clearance?
the volume of water that is being removed from the body per unit time
If we have lots of ADH circulating the blood what does that say about our free water clearance?
free water clearance is low
if ADH is low in the blood what does that say about our free water clearance?
free water clearance will be high
What is the formula for MAP for our class?
MAP = DBP + 1/3 (SBP-DBP)
What is the mean PAP we will use for our class?
16 mmHg
What is the PAP range we will use for our class?
25/8 mmHg
What is the right atrial pressure in a normal healthy person?
0 mmHg
What is the left atrial pressure in a normal healthy person?
2 mmHg
What causes a widening of pulse pressure?
stiffer arterial walls.
Where is pulse pressure about 40 mmHg? Where is it widest?
in the aorta. Pulse pressure is widest at the large arteries downstream of the aorta. And in the left ventricle.
what would you expect to see in someone who has atherosclerosis?
a wider pulse pressure
What are two things we talked about that could effect pulse pressure?
- fluid status
- stroke volume
All other things being equal what would decreasing stroke volume do to pulse pressure?
this would reduce pulse pressure
All other things being equal what would increasing stroke volume do to pulse pressure?
this would increase pulse pressure
what is the term we use to describe stretchiness?
compliance
what is the formula for compliance?
a change in volume / a change in pressure
What type of cells line the entire inside of the cardiovascular system and are the sole component of capillaries?
endothelial cells
what is normal HR and SV values we will use in our class? What CO have we been using?
HR: 72 bpm
SV: 70 cc/mL
CO: 5 L/min
What is the formula for the velocity of blood flow in a given vessel?
velocity = flow/ cross-sectional area
What is the pressure of the capillary at the arteriolar end? The venous end?
30 mmHg and 10 mmHg
what is the effect of gravity on fluids in the body?
13.6 mm below a pressure source the pressure observed at that point will be 1 mmHg higher
where is the isogravimetric point? What is another name for this?
at the level of the tricuspid. The phlebostatic axis
What is the pressure at the isogravimetric point?
0 mmHg
Why is a patient at risk for an air emboli when removing a central line when seated in an upright position?
The pressure is sub-atmospheric above the heart in the upright position
vascular distensibility takes into account what?
the original volume. It measures expandibility.
What is the formula for distensibility?
D = change in V / change in P x original V
What has the largest impact on blood flow?
the diameter of the vessel. Dilation and constriction has a massive impact on flow
When does end diastolic pressure occur?
immediately before ventricular contraction
what pressure can we use as a value of preload?
end-diastolic pressure
Excess K+ in the extracellular fluid causes the cardiac muscle to…
dilate and become flaccid
Excess calcium in the ECF causes cardiac muscle to behave how?
it becomes more spastic
