Hemodynamics

Question 1

Viscosity

Answer 1

The greater the viscosity, the slower the blood flow. Decreased viscosity will cause elevated flow velocities

Question 2

Mitral regurgitation normally does not effect what?

Answer 2

The systolic velocities in the arterial system.

Question 3

Increased resistance equals

Answer 3

Decreased flow

Question 4

Increased resistance requires an

Answer 4

Increase in pressure to maintain constant flow

Question 5

Causes of increased resistance

Answer 5

Stenosis, vasoconstriction, organ supplies not functioning properly

Question 6

High resistance characteristics

Answer 6

1. Sharp upstroke with rapid deceleration
2. Little/no diastolic flow
3. Areas fed do NOT require constant flow
4. Muscle, extremities

Question 7

Low resistance characteristics

Answer 7

1. Slow upstroke
2. Increased diastolic flow
3. Areas fed DO require constant flow
4. Brain, kidneys, spleen

Question 8

Bernoulli Effect

Answer 8

1. Pressure is higher proximal to the stenosis causing lower velocity
2. Pressure drops at the stenosis causing a large gradient and high velocity
3. Pressure increases mildly just distal to the stenosis causing drop in velocity
4. Multiple lesions affect flow more than a single lesion. Flow will decrease significantly distal to multiple lesions.
5. Collaterals can mask disease by allowing blood to course to distal locations through alternate pathways.