Lecture 1: Review & CV Function (Exam I) Flashcards
What is Clearance?
What units would be used to denote this concept?
- How much plasma is cleared of a substance per unit of time ( ex. mL/min )
What is free water clearance?
What would a high free water clearance indicate?
What is an example of a situation that would necessitate a high free water clearance?
- How much H₂O is cleared from the blood.
- ↑ free H₂O clearance = getting rid of water
- Ex. Hypervolemia
What would the normal pulse pressure in large arteries be?
How would this change in the aorta and why?
- 40mmHg (in aorta) wider in large arteries.
- PP would be less in the aorta due to increased aortic compliance.
What would be considered “stiffer”, the aorta or large arteries?
What would the result of stiffness be on the measured pulse pressure?
- Larger Arteries = stiffer = less compliance.
- ↑ stiffness = ↑ pulse pressure
What is the formula for compliance?
- C = ΔV / ΔP
What are the three benefits of increased aortic compliance?
- Increased “stretchability” allows for more pumped blood to fill up aorta.
- Decreases LV afterload.
- Functions as “rebound” secondary pump.
What is a healthy CVP and where is it measured?
- 0 mmHg measured right outside of the right atrium.
The addition of lots of volume with relatively little pressure increase would indicate a _____ compliance system.
high
The addition of little volume but relatively large pressure increases from the volume addition would be considered a ____ compliance system.
low
What is the formula for Elastance?
What can elastance be correlated with?
- Elastance = 1 / compliance
- ↑ Elastance = ↑ Rigidity
What is a normal pressure in the left atrium?
- (*2) -5 mmHg
What is a normal pressure in the left ventricle?
- 2-120 mmHg
What is a normal pressure in the right atrium?
- 0 - 3 mmHg
What is a normal pressure in the right ventricle?
- 0 - 25 mmHg
What vessel group has the greatest total cross-sectional area?
- Capillaries (4500 cm²)
What vessel has the lowest total cross-sectional area?
- Aorta (4.5 cm²)
What is the formula for blood velocity?
- Flow / Area
What structure governs blood flow into the capillaries?
- Arterioles & precapillary sphincters
What would trigger arteriole relaxation?
Why would this occur?
- H⁺, CO₂, & adenosine (metabolic byproducts)
- Arteriole relaxation = ↑ flow & movement of metabolic products.
What is the normal hydrostatic pressure at the beginning of a capillary system?
What about at the end?
What would the average pressure be throughout the capillary system?
- 30mmHg to 10mmHg
- 17mmHg
What is the plasma colloid osmotic pressure (πCAP) ?
- 28 mmHg